Improved barrier coating for produce

Abstract

Thixotropic aqueous mixtures are provided that can form very thin coatings on fruits and vegetables to extend shelf life and optimal shelf life at much lower concentrations and doses than prior art. A mixture comprising at least one smectite clay and a glycerophospholipid, and optionally a water-soluble polymer, is added to water under high shear mixing, and then applied to an agricultural product through a tank, spray lance or brush bed, or a combination thereof.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480035267.6 (22) Application Date 2024.05.24 (30) Priority Data 63 / 469,091 2023.05.26 US 63 / 469,094 2023.05.26 US (85) PCT International Application Entering National Phase Date 2025.11.26 (86) PCT International Application Application Data PCT / US2024 / 031097 2024.05.24 (87) PCT International Application Publication Data WO2024 / 249343 EN 2024.12.05 (71) Applicant: Nabaco Corporation, Address: Texas, USA (72) Inventors: G. Bill M. Amiri (74) Patent Agency: Beijing Lusheng Law Firm, 11326 Patent Attorneys: Wei Wangyang, Li Mi (51) Int.Cl. A23P 20 / 00 (2006.01) A23B 7 / 16 (2006.01) (54) Invention Title: Improved Barrier Coating for Agricultural Products (57) Abstract: A thixotropic aqueous mixture is provided that can form a very thin coating on fruits and vegetables, thereby extending shelf life and best-before date at a much lower concentration and dosage than prior art. The mixture comprises at least one montmorillonite clay and glycerophospholipids, and optionally a water-soluble polymer, added to water under high-shear mixing, and then applied to agricultural products by means of a trough, spray bar, or brush bed or a combination thereof. Claims (3 pages), Description (26 pages), Drawings (7 pages), CN 121240779 A, ​​2025.12.30, CN 1 21 24 07 79 A. 1. A thixotropic aqueous mixture for preventing dehydration and / or oxidation of agricultural products, comprising: a) montmorillonite clay; and b) glycerophospholipids. 2. The thixotropic aqueous mixture according to claim 1, wherein the montmorillonite clay is montmorillonite, lithium saponite, or bentonite, or montmorillonite and lithium saponite. 3. The thixotropic aqueous mixture according to claim 1 or 2, wherein the glycerophospholipids are lecithin; optionally, wherein the lecithin is or is derived from soybean lecithin, sunflower lecithin, or egg lecithin. 4. The thixotropic aqueous mixture according to any one of claims 1-3, wherein the montmorillonite clay is present in the thixotropic aqueous mixture in an amount of 0.5% to 6.5% by weight, optionally 1.0% to 5.0% by weight, optionally 1.0% to 1.5% by weight.5. The thixotropic aqueous mixture according to any one of claims 1-4, wherein the glycerophospholipid is present in the thixotropic aqueous mixture in an amount of 0.5% to 4.0% by weight, optionally 1.5% to 3.5% by weight, optionally 1.5% to 2.5% by weight. 6. The thixotropic aqueous mixture according to any one of claims 1-5, wherein the ratio of montmorillonite clay to the glycerophospholipid is 3:1 to 0.3:1 (w / w), optionally 1.5:1 to 0.5:1, or 1:1 to 0.5:1; optionally about 0.7:1 (w / w). 7. The thixotropic aqueous mixture according to any one of claims 1-6, further comprising an antioxidant; optionally wherein the antioxidant is sodium citrate. 8. The thixotropic aqueous mixture according to claim 7, wherein the antioxidant is present in the mixture in an amount of 0.05% to 0.5% by weight; optionally 0.1% to 0.3% by weight. 9. The thixotropic aqueous mixture according to claim 7 or 8, comprising: a) montmorillonite clay; b) lecithin; and c) sodium citrate. 10. The thixotropic aqueous mixture according to any one of claims 1-9, further comprising a water-soluble polymer. 11. The thixotropic aqueous mixture according to claim 10, wherein the water-soluble polymer is PVOH. 12. The thixotropic aqueous mixture according to claim 11, comprising: a) montmorillonite clay; b) lecithin; c) PVOH; and d) sodium citrate. 13. The thixotropic aqueous mixture according to claim 12, wherein the montmorillonite clay is bentonite, lithium saponite, or montmorillonite and lithium saponite. 14. The thixotropic aqueous mixture according to any one of claims 11-13, wherein the PVOH is present in the mixture in an amount of 1.0% to 3.0% by weight, optionally 1.5% to 2.5% by weight, optionally about 2.0% by weight. 15. The thixotropic aqueous mixture of claim 10, wherein the water-soluble polymer comprises one or more polysaccharides. 16. The thixotropic aqueous mixture of claim 15, wherein the polysaccharide is xanthan gum or gum arabic. 17. The thixotropic aqueous mixture of claim 16, comprising: (a) montmorillonite clay; (b) lecithin; (c) xanthan gum or gum arabic; and (d) sodium citrate. 18. The thixotropic aqueous mixture of claim 17, wherein the montmorillonite clay is montmorillonite or lithium saponite.19. The thixotropic aqueous mixture according to any one of claims 15-18, wherein the one or more polysaccharides are present in the mixture in an amount of 0.2% to 6.5% by weight; optionally, wherein xanthan gum is present in the mixture in an amount of 0.2% to 0.6% by weight; optionally, wherein gum arabic is present in the mixture in an amount of 0.2% to 2.0% by weight, optionally 0.5% to 2.0% by weight. 20. The thixotropic aqueous mixture according to any one of claims 1-19, wherein the total solids content of the thixotropic aqueous mixture is 2% to 10% solids, optionally 3% to 6% solids, optionally 3.5% to 5.5% solids. 21. A method of manufacturing a thixotropic aqueous mixture, comprising mixing at least one montmorillonite clay and glycerophospholipids with water under high shear to form the thixotropic aqueous mixture. 22. The method of claim 21, wherein: the at least one montmorillonite clay is montmorillonite, lithium montmorillonite, bentonite, or a combination of montmorillonite and lithium montmorillonite; and / or the glycerophospholipid is lecithin. 23. The method of claim 21 or 22, wherein: the at least one montmorillonite clay and the glycerophospholipid are combined in powder form, and then the combined powder is mixed with a solvent under high shear; or the at least one montmorillonite clay and the glycerophospholipid are added separately to water during high shear mixing. 24. The method of any one of claims 21-23, further comprising mixing sodium citrate with montmorillonite clay, glycerophospholipid, and water under high shear. 25. The method of any one of claims 21-23, further comprising mixing a water-soluble polymer with montmorillonite clay, glycerophospholipid, and water under high shear; optionally wherein the water-soluble polymer is PVOH or a polysaccharide. 26. A thixotropic mixture prepared by the method of any one of claims 21-25. 27. A method comprising: i) producing a thixotropic aqueous mixture using a high-shear method according to any one of claims 21-25; and ii) applying the thixotropic aqueous mixture to a surface of an agricultural product. 28. A method for preventing dehydration and / or oxidation of an agricultural product, comprising applying the thixotropic aqueous mixture according to any one of claims 1-20 or 26 to a surface of the agricultural product. 29. A method for delaying the ripening of an agricultural product, comprising applying the thixotropic aqueous mixture according to any one of claims 1-20 or 26 to a surface of the agricultural product, thereby delaying the ripening of the agricultural product compared to the ripening of an uncoated agricultural product.30. The method according to any one of claims 27-29, wherein the thixotropic aqueous mixture is applied to the surface of the agricultural product using an impregnation tank, a spray bar, or a brush bed, or any combination thereof; optionally, wherein the thixotropic aqueous mixture is applied using a combination of a spray bar and a brush bed, or a combination of an impregnation tank and a brush bed; Optionally, the thixotropic aqueous mixture is applied using a spray bar at a spraying ratio of 1,000 to 10,000 pounds of agricultural product per liter of thixotropic aqueous mixture; optionally, 5,000 to 8,000 pounds of agricultural product per liter of thixotropic aqueous mixture; optionally, about 7,000 pounds of agricultural product per liter of thixotropic aqueous mixture. 31. Use of the thixotropic aqueous mixture according to any one of claims 1-20 or 26 for preventing dehydration and / or oxidation of agricultural products. 32. Use of the thixotropic aqueous mixture according to any one of claims 1-20 or 26 for delaying the ripening of agricultural products. 33. The method according to any one of claims 27-30, or the use according to claim 31 or 32, wherein the agricultural product is a fruit, optionally a pome or a citrus fruit. Claims 3 / 3 Page 4 CN 121240779 A Improved Barrier Coatings for Agricultural Products Technical Field

[0001] The present invention generally relates to compositions that increase the shelf life and ready-to-eat window of agricultural products such as fruits and vegetables. These compositions form a coating on the surface of agricultural products that improves one or more barrier properties of the surface of the agricultural product, particularly gas barrier efficacy, compared to uncoated agricultural products, thereby preventing dehydration and / or oxidation of the agricultural product, which reduces the shelf life and ready-to-eat window of the agricultural product. The present invention also relates to methods of manufacturing these compositions. The present invention further provides methods of coating agricultural products (such as fruits), including applying a coating composition to the agricultural product, and methods and uses of improving the effectiveness of the barrier coating to extend the shelf life of the coated fruits and vegetables. Background Art

[0002] The shelf life and ready-to-eat window of fruits and vegetables are limited due to dehydration and exposure to oxygen in the air. Climax fruits, including apples, pears, and avocados, continue to ripen after harvest. Ethylene production, coupled with increased respiration rates, accelerates ripening, thus shortening shelf life and optimal consumption period. Fruits and vegetables often require long-term storage and frequently travel long distances before reaching consumers. Rapid ripening of produce presents a problem. Overripe or damaged fruits and vegetables are often unsellable or inedible, resulting in significant food waste. Therefore, it is desirable to increase the storage time of produce before consumption to prevent premature ripening, damage, and / or spoilage, thereby improving shelf life.

[0003] One method to reduce dehydration is to coat fruit with wax. Fruits and vegetables are often coated with wax or shellac to give them a glossy finish and retain moisture. This practice is widely used for apples, avocados, and cucumbers. These traditional coatings do not improve the shelf life of produce and do little to protect fruit from oxidation. Furthermore, wax coatings can act as carriers for fungicides and pesticides applied to produce, resulting in undesirable taste and texture in produce, especially fruit, which can be off-putting to consumers. Wax coatings are not easily removed from the surface of produce by consumers and can accumulate on the packaging line.

[0004] Recent studies have shown that fruit coatings containing a hydrated mixture of selected montmorillonite clay and appropriate polymers self-assemble into nanocomposite barrier coatings on the surface of fruits or vegetables. These coatings effectively prevent fruit oxidation and dehydration. When applied to fruit via a dip tank, these self-assembled barrier coatings can effectively extend shelf life by one or two times. However, this method requires high concentrations and high doses of coating on the fruit, which can lead to anaerobic conditions that are very detrimental to the taste and ripening of the fruit. Higher concentrations can also cause application problems due to viscosity. These thick coatings can separate from the fruit and fall off. They are also quite expensive.

[0005] Therefore, there is a need in the art for an additive that can improve the effectiveness of these barrier coatings at lower concentrations and dosages, and also for a thinner barrier coating that also extends the shelf life of agricultural products. Summary of the Invention

[0006] The present invention generally relates to compositions, methods, and uses for preventing dehydration and / or oxidation of agricultural products, or for delaying the ripening of agricultural products. The method involves coating agricultural products with the thixotropic aqueous mixture described herein. The terms “thixotropic aqueous mixture” and “thixotropic aqueous composition” (or more generally “thixotropic mixture” and “thixotropic composition”) are used interchangeably herein to refer to the thixotropic compositions and mixtures of the present invention.

[0007] According to a first aspect of the invention, a thixotropic aqueous mixture for preventing dehydration and / or oxidation of agricultural products is provided, comprising: a) montmorillonite clay; and b) glycerophospholipids. Specification 1 / 26 pages 5 CN 121240779 A

[0008] The present invention also provides a method for manufacturing the thixotropic aqueous mixture of the present invention, and a thixotropic aqueous mixture manufactured by the method of the present invention. The method of the present invention generally includes at least one mixing step performed under high shear. Thus, according to a second aspect of the present invention, a method for manufacturing a thixotropic aqueous mixture is provided, comprising mixing at least one montmorillonite clay and glycerophospholipid with water under high shear to form a thixotropic aqueous mixture. In some embodiments, the method further includes applying the thixotropic aqueous mixture to the surface of agricultural products.

[0009] Applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products yields one or more advantageous properties, as described herein.In this respect, coating the surface of agricultural products with the thixotropic aqueous mixture of the present invention improves one or more barrier properties of the agricultural product surface compared to an uncoated surface. For example, it is envisioned that coating the surface of agricultural products with the thixotropic aqueous mixture of the present invention creates a barrier between the agricultural product surface and the external environment, reducing the transfer of gases and / or moisture through the surface compared to an uncoated surface, thereby reducing oxidation, respiration, transpiration, moisture loss, and / or dehydration. Any or more of these barrier properties can contribute to improving the shelf life and / or best-before date of agricultural products.

[0010] Therefore, the present invention provides methods and uses for preventing dehydration and / or oxidation of agricultural products, and / or delaying the ripening of agricultural products. Accordingly, in a third aspect, the present invention provides a method for preventing dehydration and / or oxidation of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product; and a method for delaying the ripening of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product, thereby delaying the ripening of the agricultural product compared to an uncoated agricultural product. The method of the present invention generally comprises applying the thixotropic aqueous mixture to the surface of an agricultural product using a high-shear technique.

[0011] The present invention also provides the use of the thixotropic aqueous mixture of the present invention. Therefore, in a fifth aspect, the present invention provides the use of the thixotropic aqueous mixture of the present invention to prevent dehydration and / or oxidation of agricultural products, and further provides the use of the thixotropic aqueous mixture of the present invention to delay the ripening of agricultural products. Brief Description of the Drawings

[0012] Figure 1 shows photographs of the ripening (color change from green to pale yellow / yellow) observed 7 days after application of a thixotropic 4.5% aqueous dispersion containing 0.945% bentonite, 1.48% polyvinyl alcohol, 1.89% lecithin, and 0.18% sodium citrate in Argentina Packham pears (bottom) and a “control” Argentina Packham pear without any coating (top). It can be seen that the coated pears better retained their appealing green color and also showed fewer signs of damage on the skin compared to the uncoated control pears.

[0013] Figure 2 illustrates the percentage of weight loss of organic Gala apples coated with the thixotropic coating of the present invention compared to "control" Gala apples (uncoated) 24 days after application. It can be seen that coating the apples with the thixotropic aqueous mixture of the present invention results in a significant reduction in weight loss percentage compared to the uncoated apples of the same species.

[0014] Figure 3 illustrates the percentage of weight loss of conventional (i.e., non-organic) Bartlett pears coated with the thixotropic coating of the present invention compared to "control" Bartlett pears 9 days after application. It can be seen that coating the pears with the thixotropic aqueous mixture of the present invention results in a significant reduction in weight loss compared to the uncoated pears of the same species.

[0015] Figure 4 illustrates the percentage of weight loss of lemons coated with the thixotropic coating of the present invention compared to a "control" lemon (uncoated) 7 days after application. It can be seen that coating lemons with the thixotropic aqueous mixture of the present invention results in a significant reduction in weight loss percentage compared to uncoated lemons.

[0016] Figure 5 illustrates the percentage of weight loss of lemons coated with the thixotropic coating of the present invention compared to a "control" lemon (uncoated) 7 days after application. It can be seen that coating lemons with the thixotropic aqueous mixture of the present invention results in a significant reduction in weight loss percentage compared to uncoated lemons.

[0017] Figure 6 illustrates the percentage of weight loss of citrus fruits coated with the thixotropic coating of the present invention compared to a "control" citrus fruit (uncoated) 7 days after application. It can be seen that coating citrus fruits with the thixotropic aqueous mixture of the present invention results in a significant reduction in weight loss compared to uncoated citrus fruits.

[0018] Figure 7 illustrates the percentage of weight loss of citrus fruits coated with the thixotropic coating of the present invention compared to "control" citrus fruits (uncoated) 7 days after application. It can be seen that coating citrus fruits with the thixotropic aqueous mixture of the present invention results in a significant reduction in weight loss percentage compared to uncoated citrus fruits. Detailed Description

[0019] The following detailed description is intended to enable those skilled in the art to make and use the present invention. Specific details are set forth for ease of explanation to provide a thorough understanding of the invention. However, these specific details will be apparent to those skilled in the art that they are not essential for carrying out the invention. The description of specific applications is provided only as representative examples. Various modifications to preferred embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. The invention is not intended to be limited to the embodiments shown, but rather to be given the broadest possible scope while conforming to the principles and features disclosed herein.

[0020] It has been unexpectedly found that coating agricultural product surfaces (e.g., the skin, peel, or rind of agricultural products) with the thixotropic aqueous mixture of the present invention improves one or more barrier properties of the agricultural product surface compared to surfaces uncoated with the thixotropic aqueous mixture of the present invention (i.e., “uncoated” surfaces / “uncoated agricultural products”). As used herein, the term “uncoated” includes surfaces lacking any coating as well as surfaces coated with conventional barrier coatings (e.g., wax-based coatings). Therefore, agricultural product surfaces uncoated with the thixotropic aqueous mixture of the present invention (i.e., “uncoated”) may have different coatings or may not have any type of coating. For example, it is envisioned that coating agricultural product surfaces with the thixotropic aqueous mixture of the present invention creates a barrier between the agricultural product surface and the external environment, reducing the transfer of gases and / or moisture through the surface compared to uncoated surfaces.Therefore, when the thixotropic aqueous mixture of the present invention is coated on the surface of agricultural products, it can act as a barrier against gases and / or moisture (such as water vapor). By reducing the transfer of gases (including oxygen and carbon dioxide) through the surface of agricultural products, the thixotropic aqueous mixture of the present invention can reduce the respiration rate of agricultural products and mitigate the effects of ethylene on the ripening of agricultural products. By reducing the transfer of atmospheric oxygen through the surface of agricultural products, the thixotropic aqueous mixture of the present invention can prevent the oxidation of agricultural products. In addition, by reducing the loss of moisture (including water) through the surface of agricultural products, the thixotropic aqueous mixture of the present invention can prevent transpiration and / or dehydration of agricultural products. Any one or more of these barrier properties can help improve the shelf life and / or best-before date of agricultural products.

[0021] In a first aspect, the present invention provides a thixotropic aqueous mixture comprising: a) montmorillonite clay; and b) glycerophospholipids.

[0022] The thixotropic aqueous mixture is used to (suitably and effectively) prevent the dehydration and / or oxidation of agricultural products. Compared with uncoated agricultural products, the thixotropic aqueous mixture is also used to (suitably and effectively) delay the ripening of agricultural products coated with the mixture. Furthermore, compared to uncoated agricultural products, thixotropic aqueous mixtures (suitably and effectively) maintain or extend the shelf life of agricultural products coated with the mixture. Thixotropic aqueous mixtures are also used (suitably and effectively) to form a barrier coating on the surface of agricultural products, which improves one or more barrier properties (such as gas barrier properties) of the surface of the agricultural product to which the mixture is applied compared to an uncoated surface of the same (type) of agricultural product. Therefore, thixotropic aqueous mixtures can be referred to as coating compositions, and optionally as barrier coating compositions, such as gas and / or moisture barrier coating compositions. When the thixotropic aqueous mixture of the present invention is applied to the surface of an agricultural product, a coating is formed that acts as a barrier against the transfer of gas and / or moisture through the surface of the agricultural product. Therefore, the thixotropic aqueous mixture coating of the present invention can be referred to as a barrier coating, such as a gas barrier coating (see page 3 / 26 of CN 121240779 A) and / or a moisture barrier coating.

[0023] As used herein, the term "thixotropic" refers to a mixture having non-Newtonian fluid dynamics characteristics whose flow properties (such as apparent viscosity) vary with shear rate and shear duration. The thixotropy of aqueous mixtures is crucial for achieving one or more desired barrier properties, thus preventing dehydration and / or oxidation when coated onto agricultural product surfaces. The high shear generated during mixture preparation and / or application to agricultural product surfaces reduces the viscosity of the thixotropic aqueous mixture and decreases flow resistance. For example, when a coating mixture is sprayed onto an agricultural product surface using a spray bar, the shear generated by the pump and nozzle reduces the viscosity of the aqueous thixotropic mixture and decreases flow resistance during spraying (i.e., the thixotropic mixture is thinned out when dispensed through the nozzle).Using a high-shear application method, the amount of produce coated with a given volume of the mixture is far greater than the amount coated with the same volume of the mixture using a non-high-shear method such as immersion. For example, when applied via an immersion tank, 1 liter of the thixotropic aqueous mixture of the present invention can be used to coat 500 pounds of produce, but when applied via a spray bar, up to 7,000 pounds of produce can be coated. Once the spray hits the surface of the produce, the viscosity of the thixotropic aqueous mixture is restored, and the thixotropic aqueous mixture forms a coating or film on the surface of the produce. The coating on the surface of the produce can be further smoothed using a brush bed, making the coating more complete and uniform. In addition, brushing reorients the lamellar crystals of the montmorillonite clay to be parallel to the surface of the produce (i.e., aligned with the surface of the produce), thereby enhancing the coating.

[0024] The thixotropic aqueous mixture of the present invention contains montmorillonite clay. Any montmorillonite clay can be used in the thixotropic aqueous mixture of the present invention. For example, it is envisioned that montmorillonite clay is at least one of montmorillonite, bentonite, lithium montmorillonite, or lithium saponite (sodium lithium magnesium silicate, Na0.7Si8Mg5.5Li0.3O2O(OH)4), or any combination thereof. Particularly good results are achieved using montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises montmorillonite and / or lithium saponite. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises bentonite. When dispersed in water, montmorillonite clay forms a colloidal dispersion, which may be translucent or even transparent.

[0025] It is envisioned that montmorillonite clay is present in the thixotropic aqueous mixture in amounts, for example, from 0.5% to 6.5% by weight, optionally from 1.0% to 5.0% by weight, optionally from 1.0% to 1.5% by weight. Therefore, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; and b) glycerophospholipids. For example, in some embodiments, the thixotropic aqueous mixture comprises: a) about 1.0% to 1.5% by weight of montmorillonite clay; and b) glycerophospholipids. In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium saponite, or bentonite, or montmorillonite and lithium saponite.

[0026] The thixotropic aqueous mixture of the present invention also comprises glycerophospholipids. In particular, it is contemplated that the thixotropic aqueous mixture of the present invention comprises lecithin. Lecithin is a mixture of glycerophospholipids, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid. Common sources of lecithin include egg yolks, seafood, soybeans, milk, rapeseed oil, cottonseed oil, and sunflower oil. The exact composition of lecithin depends on its source.Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises montmorillonite clay and lecithin. For example, the lecithin may be (or derived from) sunflower lecithin, soybean lecithin, or egg lecithin. Sunflower lecithin and soybean lecithin are vegan, which may be beneficial in maintaining the vegan status of fruit and vegetable produce to which the thixotropic aqueous mixture is applied.

[0027] It is envisioned that glycerophospholipids (such as lecithin) are present in the thixotropic aqueous mixture in amounts, for example, from 0.5% to 4.0% by weight, optionally from 1.5% to 3.5% by weight, optionally from 1.5% to 2.5% by weight, and optionally (about) 2% by weight. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) montmorillonite clay and b) glycerophospholipids in an amount, for example, from 0.5% to 4.0% by weight, such as from 1.5% to 3.5% by weight, such as from 1.5% to 2.5% by weight, such as about 2% by weight. In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) montmorillonite clay and b) lecithin in an amount, for example, from 0.5% to 4.0% by weight, such as from 1.5% to 3.5% by weight, such as from 1.5% to 2.5% by weight, such as about 2% by weight. For example, in some embodiments, the thixotropic aqueous mixture of the present invention comprises a) montmorillonite clay and b) lecithin in an amount, such as about 2% by weight.

[0028] Therefore, the thixotropic aqueous mixture of the present invention is contemplated to comprise: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; and b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of glycerophospholipids. For example, the thixotropic aqueous mixture of the present invention may comprise: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; and b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of lecithin. In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 1.0% to 1.5% by weight of montmorillonite clay; and b) about 2% by weight of glycerophospholipids (such as lecithin). In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite.

[0029] In some embodiments, the ratio of montmorillonite clay to glycerophospholipids (such as lecithin) is 3:1 to 0.3:1 (w / w); optionally 3:1 to 1:1, such as about 1.4:1; or optionally 1.5:1 to 0.5:1 (w / w), such as 1:1 to 0.5:1, or 0.7:1 to 0.5:1; optionally about 0.7:1 or 0.6:1. For example, the thixotropic aqueous mixture of the present invention may contain montmorillonite clay:lecithin in a ratio of about 0.7:1.

[0030] The thixotropic aqueous mixture may further contain an antioxidant. Containing an antioxidant is useful when it is necessary to limit the oxidation of agricultural products. In some embodiments, the antioxidant is or contains sodium citrate. Sodium citrate also acts as an anti-flocculation agent, which is useful when preparing mixtures using hard water, which can cause the coating to flocculate. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises montmorillonite clay, glycerophospholipids, and sodium citrate. For example, the thixotropic aqueous mixture may comprise montmorillonite clay, lecithin, and sodium citrate.

[0031] It is contemplated that an antioxidant (optionally sodium citrate) is present in any thixotropic aqueous mixture in an amount of 0.05% to 0.5% by weight, optionally 0.1% to 0.3% by weight, optionally (about) 0.2% by weight, or 0.25% by weight.

[0032] Therefore, the thixotropic aqueous mixture of the present invention is envisioned to comprise: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of glycerophospholipids; and c) 0.05 wt% to 0.5 wt%, such as 0.1 wt% to 0.3 wt%, such as about 0.2 wt% or 0.25 wt% of an antioxidant. For example, the thixotropic aqueous mixture of the present invention comprises: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; and c) 0.05% to 0.5% by weight, such as 0.1% to 0.3% by weight, such as about 0.2% or 0.25% by weight of an antioxidant.For example, the thixotropic aqueous mixture of the present invention comprises: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; and c) 0.05% to 0.5% by weight, such as 0.1% to 0.3% by weight, such as about 0.2% or 0.25% by weight of sodium citrate. In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 1.0% to 1.5% by weight of montmorillonite clay; b) about 2% by weight of lecithin; and c) about 0.2% or 0.25% by weight of an antioxidant. In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite. Specification 5 / 26 page 9 CN 121240779 A

[0033] In some embodiments, the thixotropic aqueous mixture of the present invention comprises 0.45% to 6.5% by weight (e.g., about 5.0% or 6.0% by weight) of montmorillonite, 2.0% to 4.0% by weight of lecithin, and about 0.2% by weight of sodium citrate. Other thixotropic aqueous mixtures of the present invention comprise: 1.0% to 1.5% by weight of montmorillonite; about 2% by weight of lecithin; and about 0.2% by weight of sodium citrate.

[0034] The thixotropic aqueous mixture may also comprise one or more water-soluble polymers. Suitable water-soluble polymers incorporated into the thixotropic aqueous mixtures of the present invention include synthetic water-soluble polymers, semi-synthetic water-soluble polymers, or natural water-soluble polymers.

[0035] An example of a synthetic water-soluble polymer useful in the present invention is polyvinyl alcohol (PVOH). Therefore, in some embodiments, the thixotropic aqueous mixtures of the present invention contain PVOH. For example, the thixotropic aqueous mixtures of the present invention may contain: a) montmorillonite clay; b) lecithin; c) PVOH. In some embodiments, the thixotropic aqueous mixtures of the present invention may contain: a) montmorillonite clay; b) lecithin; c) PVOH; and d) an antioxidant, optionally sodium citrate. For example, the thixotropic aqueous mixture of the present invention may contain: a) lithium saponite; b) lecithin; c) PVOH; and d) sodium citrate; such as a) montmorillonite and lithium saponite; b) lecithin; c) PVOH; and d) sodium citrate, or the thixotropic aqueous mixture of the present invention may contain: a) bentonite; b) lecithin; c) PVOH; and d) sodium citrate.

[0036] It is envisioned that PVOH be present in any thixotropic aqueous mixture in an amount of 1.0 wt% to 3.0 wt%, optionally 1.5 wt% to 2.5 wt%, optionally about 2.0 wt%. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) montmorillonite clay; b) glycerophospholipids; and c) PVOH in an amount of 1.0 wt% to 3.0 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2.0 wt%. For example, the thixotropic aqueous mixture of the present invention comprises: a) montmorillonite clay; b) lecithin; and c) PVOH in an amount of 1.0 wt% to 3.0 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2.0 wt%. In any of these embodiments, the thixotropic aqueous mixture of the present invention may also comprise an antioxidant, such as sodium citrate.

[0037] Therefore, the thixotropic aqueous mixture of the present invention is contemplated to comprise: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of glycerophospholipids; and c) 1.0 wt% to 3.0 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2.0 wt% of PVOH. For example, the thixotropic aqueous mixture of the present invention comprises: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; and c) 1.0% to 3.0% by weight, such as 1.5% to 2.5% by weight, such as about 2.0% by weight of PVOH. For example, the thixotropic aqueous mixture of the present invention comprises: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; c) 1.0% to 3.0% by weight, such as 1.5% to 2.5% by weight, such as about 2.0% by weight of PVOH; and d) 0.05% to 0.5% by weight, such as 0.1% to 0.3% by weight, such as about 0.2% or 0.25% by weight of an antioxidant, optionally sodium citrate.In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 1.0% to 1.5% by weight of montmorillonite clay; b) about 2% by weight of lecithin; c) about 2.0% by weight of PVOH; and d) about 0.2% or 0.25% by weight of sodium citrate. In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite.

[0038] For example, the thixotropic aqueous mixture of the present invention may comprise about 1.3% by weight of montmorillonite clay, about 2.0% by weight of lecithin, about 2.0% by weight of PVOH, and about 0.25% by weight of sodium citrate (e.g., about 0.6% by weight of lithium saponite and 0.7% by weight of montmorillonite). The thixotropic aqueous mixture of the present invention may alternatively comprise about 1.6 wt% montmorillonite clay, about 3.0 wt% lecithin, about 2.5 wt% PVOH, and about 0.20 wt% sodium citrate (e.g., about 0.8 wt% lithium saponite and 0.8 wt% montmorillonite). A further alternative thixotropic aqueous mixture of the present invention comprises about 1.1 wt% lithium saponite, about 2.3 wt% lecithin, about 2.1 wt% PVOH, and about 0.2 wt% sodium citrate. A still further alternative thixotropic aqueous mixture of the present invention comprises about 1.0 wt% bentonite, about 1.9 wt% lecithin, about 1.5 wt% PVOH, and about 0.2 wt% sodium citrate.

[0039] In some embodiments, the ratio of PVOH to montmorillonite clay in the thixotropic aqueous mixture of the present invention is from 1.25:1 to 2.5:1 (w / w), optionally wherein the ratio of PVOH to montmorillonite clay is from 1.5:1 to 2:1 (w / w). In some embodiments, the ratio of PVOH to lecithin in the thixotropic aqueous mixture of the present invention is from 0.7:1 to 1.1:1 (w / w), optionally wherein the ratio of PVOH to lecithin is from 0.8:1 to 1:1 (w / w).

[0040] In other embodiments, the water-soluble polymer is a natural water-soluble polymer. As used herein, the term “natural” or “naturally occurring” means a water-soluble polymer that is present in or derived from nature, rather than being man-made or created. This term does not require that the polymer be “directly derived from nature.” A “natural” or “naturally occurring” water-soluble polymer can be a natural equivalent, but this is not mandatory. Examples of naturally occurring water-soluble polymers useful in the present invention include polysaccharides.

[0041] In some embodiments, the thixotropic aqueous mixture of the present invention comprises polysaccharides. For example, the thixotropic aqueous mixture of the present invention may comprise: a) montmorillonite clay; b) lecithin; and c) polysaccharides.In some embodiments, the thixotropic aqueous mixture of the present invention may comprise: a) montmorillonite clay; b) lecithin; c) polysaccharides; and d) an antioxidant, optionally sodium citrate.

[0042] Examples of polysaccharides suitable for inclusion in the thixotropic aqueous mixture of the present invention include xanthan gum, gum arabic, pullullan, pectin, and carboxymethyl cellulose. Particularly good results have been achieved using xanthan gum or gum arabic. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises xanthan gum or gum arabic. For example, the thixotropic aqueous mixture of the present invention may comprise: a) montmorillonite clay; b) lecithin; and c) xanthan gum or gum arabic. In some embodiments, the thixotropic aqueous mixture of the present invention may comprise: a) montmorillonite clay; b) lecithin; c) xanthan gum or gum arabic; and d) an antioxidant, optionally sodium citrate. In any of these embodiments, the montmorillonite clay may be, for example, montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite. For example, the thixotropic aqueous mixture of the present invention may contain: a) montmorillonite; b) lecithin; c) xanthan gum or gum arabic; and d) sodium citrate; or the thixotropic aqueous mixture of the present invention may contain: a) lithium saponite; b) lecithin; c) xanthan gum or gum arabic; and d) sodium citrate.

[0043] It is contemplated that the polysaccharide is present in any thixotropic aqueous mixture in an amount of 0.1 wt% to 6.5 wt%; optionally 0.2 wt% to 2.0 wt%; optionally 0.2 wt% to 1.5 wt%. For example, it is contemplated that xanthan gum is present in the mixture in an amount of 0.2 wt% to 0.8 wt%; optionally 0.3 wt% to 0.5 wt%. In other embodiments, gum arabic is present in the mixture in an amount of 0.2% to 4.0% by weight; optionally, 0.5% to 2.0% by weight.

[0044] In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of glycerophospholipids; and c) 0.1% to 6.5% by weight, such as 0.2% to 2.0% by weight, such as about 0.2% to 1.5% by weight of polysaccharides.For example, the thixotropic aqueous mixture of the present invention may contain: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of lecithin; and c) 0.1 wt% to 6.5 wt%, such as 0.2 wt% to 2.0 wt%, such as about 0.2 wt% to 1.5 wt% of polysaccharides. For example, the thixotropic aqueous mixture of the present invention may comprise: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; c) 0.1% to 6.5% by weight, such as 0.2% to 2.0% by weight, such as 0.2% to 1.5% by weight of polysaccharides; and d) 0.05% to 0.5% by weight, such as 0.1% to 0.3% by weight, such as about 0.2% or 0.25% by weight of an antioxidant, optionally sodium citrate. In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 1.0% to 1.5% by weight of montmorillonite clay; b) about 2% by weight of lecithin; c) 0.1% to 6.5% by weight of polysaccharides, such as 0.2% to 2.0% by weight; and d) about 0.2% or 0.25% by weight of sodium citrate. In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium montmorillonite, or a combination of montmorillonite and lithium montmorillonite.

[0045] Therefore, the thixotropic aqueous mixture of the present invention is contemplated to comprise: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of glycerophospholipids; and c) 0.2 wt% to 0.8 wt%, such as 0.3 wt% to 0.5 wt% of xanthan gum.For example, the thixotropic aqueous mixture of the present invention may comprise: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; and c) 0.2% to 0.8% by weight, such as 0.3% to 0.5% by weight of xanthan gum. For example, the thixotropic aqueous mixture of the present invention may comprise: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; c) 0.2% to 0.8% by weight, such as 0.3% to 0.5% by weight of xanthan gum; and d) 0.05% to 0.5% by weight, such as 0.1% to 0.3% by weight, such as about 0.2% or 0.25% by weight of an antioxidant, optionally sodium citrate. In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 1.0% to 1.5% by weight of montmorillonite clay; b) about 2% by weight of lecithin; c) 0.3% to 0.5% by weight of xanthan gum; and about 0.2% or 0.25% by weight of sodium citrate. In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium montmorillonite, or a combination of montmorillonite and lithium montmorillonite.

[0046] The thixotropic aqueous mixture of the present invention is also envisioned to comprise: a) 0.5 wt% to 6.5 wt%, such as 1.0 wt% to 5.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite clay; b) 0.5 wt% to 4.0 wt%, such as 1.5 wt% to 3.5 wt%, such as 1.5 wt% to 2.5 wt%, such as about 2 wt% of glycerophospholipids; and c) 0.2 wt% to 4.0 wt%, such as 0.5 wt% to 2.0 wt% of gum arabic. For example, the thixotropic aqueous mixture of the present invention may comprise: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; and c) 0.2% to 4.0% by weight, such as 0.5% to 2.0% by weight of gum arabic.For example, the thixotropic aqueous mixture of the present invention may comprise: a) 0.5% to 6.5% by weight, such as 1.0% to 5.0% by weight, such as 1.0% to 1.5% by weight of montmorillonite clay; b) 0.5% to 4.0% by weight, such as 1.5% to 3.5% by weight, such as 1.5% to 2.5% by weight, such as about 2% by weight of lecithin; c) 0.2% to 4.0% by weight, such as 0.5% to 2.0% by weight of gum arabic; and d) 0.05% to 0.5% by weight, such as 0.1% to 0.3% by weight, such as about 0.2% or 0.25% by weight of an antioxidant, optionally sodium citrate. In some embodiments, the thixotropic aqueous mixture of the present invention comprises: a) 1.0% to 1.5% by weight of montmorillonite clay; b) about 2% by weight of lecithin; c) 0.5% to 2.0% by weight of gum arabic; and d) about 0.2% by weight of sodium citrate. In any of these embodiments, the montmorillonite clay may be montmorillonite, lithium montmorillonite, or a combination of montmorillonite and lithium montmorillonite.

[0047] In some embodiments, the ratio of polysaccharide to montmorillonite clay in the thixotropic aqueous mixture of the present invention is 5:1 to 1:5 (w / w), optionally 1:2 to 1:4 (w / w). For example, the ratio of xanthan gum to montmorillonite clay can be 1:2 to 1:5, such as 1:2.5 to 1:4 (w / w); or the ratio of gum arabic to montmorillonite clay can be 5:1 to 1:4; optionally 1:2 to 1:3.5, optionally about 1:2.5 (w / w).

[0048] In some embodiments, the ratio of polysaccharides to glycerophospholipids (such as lecithin) in the thixotropic aqueous mixture of the present invention is 3:1 to 1:10 (w / w), optionally 1.5:1 to 1:5 (w / w). For example, a xanthan gum to lecithin ratio of 1:1 to 1:10 is envisioned, such as 1:3 to 1:5 (w / w), such as about 1:5 (w / w); or a gum arabic to lecithin ratio of 3:1 to 1:3, such as 1.5:1 to 1:2.5, such as 1:1.5 to 1:2.5 (w / w) or 1:1.5 to 1:2.0 (w / w).

[0049] Food-grade montmorillonite clay, glycerophospholipids (such as lecithin), PVOH and / or polysaccharides (such as xanthan gum or gum arabic) are particularly suitable for use in this invention. As used herein, the term "food-grade" means a substance that is safe for human or animal consumption and is permitted to come into direct contact with food intended for human or animal consumption.

[0050] The thixotropic aqueous mixture of the present invention contains water. Montmorillonite clay and other solids are dispersed in water, thereby forming a colloidal dispersion. Water can also act as a solvent for any water-soluble polymers in the mixture.In some embodiments, the thixotropic aqueous mixture comprises water and another solvent (optionally, a food-grade solvent), such as ethanol. If a volatile solvent such as ethanol is present, its proportion in the total solvent of the mixture does not exceed 25%. In some embodiments, the thixotropic aqueous mixture of the present invention is an aqueous colloidal dispersion comprising 2%–10% solids, optionally 3%–6% solids; optionally 3.5%–5.5% solids. In the aqueous colloidal dispersion, montmorillonite is not dissolved in the solution but dispersed, allowing individual clay flakes to remain in the colloidal dispersion. The solids content of the aqueous colloidal dispersion is measured by drying a known volume of the dispersion and weighing the dry solids.

[0051] The thixotropic aqueous mixture is generally edible, meaning it is safe for human or animal consumption. In some embodiments, the thixotropic aqueous mixture does not adversely modify the agricultural product to which it has been applied. For example, if the agricultural product is organic, the thixotropic aqueous mixture is also organic. As used herein, the term "organic" means a component that, once applied to an agricultural product, does not alter the organic state of the product. Therefore, these components meet the standards for organically produced agricultural products, such as the "organic" declaration requirements established by the USDA National Organic Program (NOP). In some embodiments, the organic thixotropic aqueous mixture contains no inorganic components, wherein, as used herein, the term "inorganic" means a component that, once applied to an agricultural product, alters the organic state of the product.

[0052] The present invention also provides a method for manufacturing the thixotropic aqueous mixture of the present invention, and mixtures manufactured by these methods. The method for manufacturing the thixotropic aqueous mixture generally includes at least one mixing step performed under high shear.

[0053] Therefore, in a second aspect, the present invention provides a method for manufacturing the thixotropic aqueous mixture of the present invention. The method includes mixing at least one montmorillonite clay and glycerophospholipids (such as lecithin), and optionally one or more other components described herein, with water. At least one mixing step is performed under high shear. Thus, the thixotropic aqueous mixture of the present invention is formed.

[0054] In the method of the present invention, montmorillonite clay and other solids are dispersed in water. Water may also act as a solvent for water-soluble polymers (if present). In some embodiments, the method uses water and another solvent (optionally, a food-grade solvent), optionally a volatile solvent, such as ethanol. If a volatile solvent such as ethanol is present, its proportion in the total solvent used in the method does not exceed 25%.

[0055] The method of the present invention for producing thixotropic aqueous mixtures involves at least one step performed under high shear.The methods or steps described herein involving high-shear mixing can be performed using any known high-shear mixer, such as a blade mixer, a Cowles dissolver, or a colloid mill. High-shear mixing requires equipment with high RPM and high horsepower to ensure that the dispersing blades can reach maximum speeds of 2,500 to 5,000 feet per minute. High-shear mixing processes may take 1–2 hours. High-shear blenders can be used when mixing smaller batches of the composition. The advantage of high-shear methods is that they achieve rapid dispersion of montmorillonite clay in water, and / or rapid mixing of montmorillonite clay with one or more other components of the mixture to form a thixotropic aqueous mixture, ensuring a uniform dispersion of montmorillonite clay particles (lamellae). When using standard mixing methods that do not involve high shear (such as tanks with paddle stirrers), mixing montmorillonite clay with other components in water can never completely disperse the montmorillonite clay to form a uniformly dispersed mixture. This is because montmorillonite clay lamellars are stacked together by many weak bonds (such as hydrogen bonds and ionic dipole interactions), which together generate strong cohesive forces. Standard mixing is insufficient to overcome this cohesive energy. When methods involving high shear are used, the increased energy and enormous forces generated by high shear are sufficient to break the forces binding these clay flakes together. Therefore, the high-shear method for producing the thixotropic aqueous mixture of the present invention is very effective.

[0056] In some embodiments, montmorillonite clay and glycerophospholipids (such as lecithin) are combined in powder form, and then the montmorillonite clay and glycerophospholipid "premix" is combined with water (e.g., added to water) and mixed under high-shear mixing conditions to disperse the montmorillonite clay and glycerophospholipids in the water.

[0057] Alternatively, it is contemplated that montmorillonite clay and glycerophospholipids (such as lecithin) be added to water separately and mixed under high shear. In these embodiments, "separately" adding components encompasses adding the components to water simultaneously or adding each component sequentially. Therefore, in some embodiments, the method includes adding at least one montmorillonite clay to water, followed by high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, and then adding a glycerophospholipid (such as lecithin) to the aqueous colloidal dispersion, optionally further subjecting it to high-shear mixing. In other embodiments, the method includes adding montmorillonite clay and a glycerophospholipid (such as lecithin) to water, followed by mixing under high shear.

[0058] In some embodiments, the method of the present invention for producing a thixotropic aqueous mixture includes mixing: a) at least one montmorillonite clay; b) a glycerophospholipid (such as lecithin) and c) an antioxidant (such as sodium citrate) with water to form a thixotropic aqueous mixture. In some embodiments, the method includes mixing: a) at least one montmorillonite clay; b) lecithin and c) sodium citrate with water to form a thixotropic aqueous mixture. At least one mixing step in the method is performed under high shear.

[0059] It is envisioned to mix montmorillonite clay, glycerophospholipids (such as lecithin), and antioxidants (such as sodium citrate) together in powder form, and then combine this "premix" of montmorillonite clay, glycerophospholipids, and antioxidants with water (as added), and mix under high-shear mixing conditions. Alternatively, it is envisioned to add montmorillonite clay, glycerophospholipids (such as lecithin), and antioxidants (such as sodium citrate) separately to water and mix under high-shear conditions. In these embodiments, adding components "separately" encompasses adding components to water simultaneously, adding two components simultaneously, adding them sequentially with another component, or adding each component in sequence. Thus, in some embodiments, the method includes adding montmorillonite clay to water, then performing high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, and then adding glycerophospholipids (such as lecithin) and antioxidants (such as sodium citrate) to the aqueous colloidal dispersion, optionally further performing high-shear mixing. In other embodiments, the method includes adding montmorillonite clay and glycerophospholipids (such as lecithin) to water, then mixing under high shear, and then adding an antioxidant (such as sodium citrate) to the mixture, optionally further performing high-shear mixing. In a further embodiment, the method includes adding montmorillonite clay to water, then performing high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, then adding glycerophospholipids (such as lecithin) to the aqueous colloidal dispersion, optionally further performing high-shear mixing, and then adding an antioxidant (such as sodium citrate) to the mixture, optionally further performing high-shear mixing.

[0060] In some embodiments, the method of the present invention for producing a thixotropic aqueous mixture includes mixing: a) at least one montmorillonite clay; b) glycerophospholipids (such as lecithin); and c) a water-soluble polymer (such as PVOH or polysaccharide) with water to form a thixotropic aqueous mixture. In some embodiments, the method includes mixing: a) at least one montmorillonite clay; b) lecithin; and c) PVOH or a polysaccharide (such as xanthan gum or gum arabic) with water to form a thixotropic aqueous mixture. At least one mixing step in the method is performed under high shear.

[0061] It is envisioned to mix montmorillonite clay, glycerophospholipids (such as lecithin), and a water-soluble polymer (such as PVOH or a polysaccharide) together in powder form, and then combine this "premix" of montmorillonite clay, glycerophospholipids, and polymer with water (such as an additive) and mix under high shear mixing conditions. Alternatively, it is envisioned to add montmorillonite clay, glycerophospholipids (such as lecithin), and a water-soluble polymer (such as PVOH or a polysaccharide) separately to water and mix under high shear.In these embodiments, "separately" adding components encompasses adding components to water simultaneously, adding two components simultaneously, adding them sequentially with another component, or adding each component sequentially. Thus, in some embodiments, the method includes adding montmorillonite clay to water and then performing high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, followed by adding glycerophospholipids (such as lecithin) and water-soluble polymers (such as PVOH or polysaccharides) to the aqueous colloidal dispersion, optionally further performing high-shear mixing. In other embodiments, the method includes adding montmorillonite clay and glycerophospholipids (such as lecithin) to water, then mixing under high shear, followed by adding a water-soluble polymer (such as PVOH or polysaccharides) to the mixture, optionally further performing high-shear mixing. In a further embodiment, the method includes adding montmorillonite clay to water, followed by high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, then adding glycerophospholipids (such as lecithin) to the aqueous colloidal dispersion, optionally further performing high-shear mixing, and then adding a water-soluble polymer (such as PVOH or polysaccharide) to the mixture, optionally further performing high-shear mixing.

[0062] In some embodiments, the method of the present invention for producing a thixotropic aqueous mixture includes mixing: a) at least one montmorillonite clay; b) glycerophospholipids (such as lecithin); c) a water-soluble polymer (such as PVOH or polysaccharide) and d) an antioxidant (such as sodium citrate) with water to form a thixotropic aqueous mixture. In some embodiments, the method includes mixing: a) at least one montmorillonite clay; b) lecithin; c) PVOH or polysaccharide (such as xanthan gum or gum arabic) and d) sodium citrate with water to form a thixotropic aqueous mixture. At least one mixing step of the method is performed under high shear.

[0063] It is envisioned to mix montmorillonite clay, glycerophospholipids (such as lecithin), water-soluble polymers (such as PVOH or polysaccharides), and antioxidants (sodium citrate) together in powder form, and then combine this "premix" of montmorillonite clay, glycerophospholipids, polymers, and antioxidants with water (as added), and mix under high-shear mixing conditions. Alternatively, it is envisioned to add montmorillonite clay, glycerophospholipids (such as lecithin), water-soluble polymers (such as PVOH or polysaccharides), and antioxidants (such as sodium citrate) separately to water and mix under high-shear conditions. In these embodiments, "separately" adding components encompasses adding components to water simultaneously, adding two components simultaneously, adding them sequentially with another component, or adding each component in sequence.Therefore, in some embodiments, the method includes adding montmorillonite clay to water and then performing high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, followed by adding glycerophospholipids (such as lecithin), a water-soluble polymer (such as PVOH or polysaccharides), and an antioxidant (such as sodium citrate) to the aqueous colloidal dispersion, optionally further performing high-shear mixing. In other embodiments, the method includes adding montmorillonite clay and glycerophospholipids (such as lecithin) to water, then mixing under high shear, followed by adding a water-soluble polymer (such as PVOH or polysaccharides) and an antioxidant (such as sodium citrate) to the mixture, optionally further performing high-shear mixing. In a further embodiment, the method includes adding montmorillonite clay to water and then performing high-shear mixing to form an aqueous colloidal dispersion of montmorillonite clay in water, then adding glycerophospholipids (such as lecithin) to the aqueous colloidal dispersion, optionally further performing high-shear mixing, then adding a water-soluble polymer (such as PVOH or polysaccharide) to the mixture, optionally further performing high-shear mixing, and then adding an antioxidant (such as sodium citrate) to the mixture, optionally further performing high-shear mixing.

[0064] The descriptions and definitions provided herein in the context of thixotropic aqueous mixtures of the present invention are equally applicable to the methods of manufacturing thixotropic aqueous mixtures of the present invention. In particular, the montmorillonite clay and glycerophospholipids used in the method may each be used as described in the thixotropic aqueous mixtures of the present invention, and may each be used in the amounts and / or proportions described in the context of thixotropic aqueous mixtures of the present invention. In embodiments of the method using antioxidants and / or water-soluble polymers, these components may each be used as described in the thixotropic aqueous mixtures of the present invention, and may each be used in the amounts and / or proportions described in the context of thixotropic aqueous mixtures of the present invention.

[0065] The present invention also provides thixotropic aqueous mixtures prepared by any of the methods of the present invention. For example, thixotropic aqueous mixtures prepared by any of the methods of the present invention may comprise montmorillonite clay (such as montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite) and lecithin. In some embodiments, thixotropic aqueous mixtures prepared by any of the methods of the present invention comprise montmorillonite clay, lecithin, and sodium citrate. In some embodiments, thixotropic aqueous mixtures prepared by any of the methods of the present invention comprise montmorillonite clay, lecithin, PVOH, and sodium citrate; or comprise montmorillonite clay, lecithin, polysaccharides (such as xanthan gum or gum arabic), and sodium citrate. Thixotropic aqueous mixtures prepared by any of the methods of the present invention may be edible and may optionally be organic. These terms have the meanings defined herein.

[0066] It is contemplated that any method of manufacturing the thixotropic aqueous mixture of the present invention may further include applying the thixotropic aqueous mixture to the surface of an agricultural product. Therefore, the present invention provides a method comprising: i) manufacturing the thixotropic aqueous mixture using the high-shear method of the present invention; and ii) applying the thixotropic aqueous mixture to the surface of an agricultural product. The thixotropic aqueous mixture forms a coating on the surface of the applied agricultural product. As defined herein, the coating imparts one or more beneficial barrier properties to the surface of the agricultural product. The coating may prevent dehydration and / or oxidation of the agricultural product; and / or, compared to uncoated agricultural products, the coating may delay the ripening of the agricultural product. Therefore, the coating may extend the shelf life of the product compared to the same agricultural product lacking the coating of the present invention.

[0067] In a third aspect, the present invention provides a method comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product to achieve one or more beneficial properties. In some embodiments, the present invention provides a method for improving one or more barrier properties (such as gas and / or moisture barrier properties) of the surface of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product, thereby improving one or more barrier properties of the surface compared to the barrier properties of an uncoated agricultural product surface. In some embodiments, the present invention provides a method for preventing dehydration and / or oxidation of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product. In some embodiments, the present invention provides a method for delaying the ripening of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product, thereby delaying the ripening of the agricultural product compared to the ripening of an uncoated agricultural product. In some embodiments, the present invention provides a method for extending the shelf life of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product, thereby extending the shelf life of the agricultural product compared to the shelf life of an uncoated agricultural product.

[0068] As used herein, the term "agricultural product" refers to crops produced on a farm. In some embodiments, agricultural products are fruits. In some embodiments, agricultural products are climacteric fruits, such as pome fruits or avocados. In some embodiments, the agricultural product is a pome fruit (such as an apple or pear), a stone fruit (including avocados and cherries), a citrus fruit (such as a lemon or citrus) or a tomato. The invention is particularly applicable to pome fruits, and more particularly to apples, pears and / or quince. In some embodiments, the agricultural product is a vegetable product. For example, a vegetable product may be a cucumber or a mushroom.

[0069] In all aspects of the invention, reference to the “surface” of an agricultural product (such as a fruit or vegetable) refers to the outer surface of the agricultural product, which, depending on the type of agricultural product, may be called the peel, outer skin, or pericarp.For example, in some embodiments, the present invention relates to thixotropic aqueous mixtures and methods for improving one or more barrier properties (such as gas and / or moisture barrier properties) of the skin of pome fruits (such as apples or pears) compared to the same, uncoated pome fruits. In some embodiments, the thixotropic aqueous mixtures and methods of the present invention reduce the transfer of gases (including oxygen and carbon dioxide) through the skin of pome fruits, thereby reducing the respiration rate of pome fruits and slowing the ripening effect of ethylene on pome fruits. By reducing the transfer of atmospheric oxygen through the pome fruit skin, the thixotropic aqueous mixtures and methods of the present invention can prevent fruit oxidation. In addition, by reducing the loss of moisture (including water) through the pome fruit skin, the thixotropic aqueous mixtures of the present invention can prevent transpiration and / or dehydration of the fruit. Any or more of these barrier properties can contribute to improving the shelf life and / or best-before date of pome fruits.

[0070] The thixotropic aqueous mixture used in the methods of the present invention can be any of the thixotropic aqueous mixtures of the present invention described herein. In some embodiments, the thixotropic aqueous mixture used in the methods of the present invention comprises at least one montmorillonite clay (such as montmorillonite, lithium zeolite, bentonite, or a combination of montmorillonite and lithium zeolite) and lecithin. In some embodiments, the thixotropic aqueous mixture used in any method of the present invention comprises montmorillonite clay, lecithin, and sodium citrate. In some embodiments, the thixotropic aqueous mixture used in any method of the present invention comprises montmorillonite clay, lecithin, PVOH, and sodium citrate; or comprises montmorillonite clay, lecithin, polysaccharides (such as xanthan gum or gum arabic), and sodium citrate. The descriptions and definitions provided herein in the context of the thixotropic aqueous mixtures of the present invention are equally applicable to the methods of preparing the thixotropic aqueous mixtures of the present invention. In particular, the montmorillonite clay and glycerophospholipids in the thixotropic aqueous mixture used in any method of the present invention may each be used as described in the thixotropic aqueous mixtures of the present invention, and may each be used in the amounts and / or proportions described in the context of the thixotropic aqueous mixtures of the present invention. In methods of using thixotropic aqueous mixtures comprising antioxidants and / or water-soluble polymers, these components may each be used as described in the thixotropic aqueous mixtures of the present invention, and may each be used in the amounts and / or proportions described in the context of the thixotropic aqueous mixtures of the present invention.

[0071] In some embodiments, the thixotropic aqueous mixture is applied to the produce prior to harvest, but in other embodiments, the thixotropic aqueous mixture is applied after harvest. Applying the thixotropic aqueous mixture prior to harvest provides the greatest effect on shelf life, but substantial effects can also be obtained if applied after storage.

[0072] It is envisioned that in the method of the present invention relating to applying a thixotropic aqueous mixture to the surface of an agricultural product, the thixotropic aqueous mixture can be applied by any one or more methods suitable for applying a thin and uniform coating of the mixture to the surface of the agricultural product. For example, the thixotropic aqueous mixture can be applied to the surface of the agricultural product by immersing the agricultural product in the thixotropic aqueous mixture, and / or by spraying and / or brushing the thixotropic aqueous mixture onto the surface of the agricultural product. In some embodiments, the thixotropic aqueous mixture is applied to the surface of the agricultural product by spraying (optionally by a combination of spraying and brushing). In other embodiments, the thixotropic aqueous mixture is applied to the surface of the agricultural product by a combination of immersion and brushing. In some embodiments, the application method involves high shear.

[0073] Therefore, in some embodiments, an immersion tank, a spray bar, or a brush bed, or any combination thereof, can be used to apply the thixotropic aqueous mixture to the surface of the agricultural product.

[0074] In some embodiments, an immersion tank is used to apply the thixotropic aqueous mixture. An impregnation tank is a device capable of holding 5,000 to 10,000 liters of the thixotropic aqueous mixture of the present invention, which facilitates the soaking of agricultural products for coating the surface of the agricultural products (see page 13 / 26 of the specification, CN 121240779 A). For example, the agricultural products are immersed in the thixotropic aqueous mixture once for 2 to 5 minutes. The thixotropic aqueous mixture of the present invention can be applied using an impregnation tank at a ratio of approximately 500 pounds of agricultural products per liter of mixture. After applying the mixture using an impregnation tank, the agricultural products can be placed on a drain belt to remove excess mixture.

[0075] It is envisioned that the thixotropic aqueous mixture can be applied to the surface of agricultural products using a combination of an impregnation tank and a brush bed. A brush bed typically has 6 to 12 rolling brushes that serve to convey and brush the agricultural products. After the thixotropic aqueous mixture is applied to the surface of the agricultural products, these brushes will evenly and effectively coat the agricultural products with the thixotropic aqueous mixture of the present invention. The use of a brush bed is particularly advantageous because it ensures that the thixotropic aqueous mixture is evenly coated on the agricultural products and avoids the use of excessive mixture.

[0076] In some embodiments, the thixotropic aqueous mixture is applied using a spray bar (optionally a combination of a spray bar and a brush bed). A spray bar is a device comprising a pump and at least one nozzle for spraying the thixotropic aqueous mixture onto the agricultural product. During the application phase, the high shear generated by the pump and nozzle of the spray bar reduces the viscosity of the thixotropic aqueous mixture and decreases flow resistance when applied to the surface of the agricultural product. The spray bar can be used to apply the thixotropic aqueous mixture at a spraying rate of at least 1000 pounds of agricultural product per liter of thixotropic aqueous mixture; for example, 1000 to 7000 pounds of agricultural product per liter of mixture, or 3000 to 7000 pounds of agricultural product per liter of mixture.Once the thixotropic aqueous mixture impacts the surface of the agricultural product (i.e., the thixotropic aqueous mixture comes into contact with the surface of the agricultural product), the viscosity is restored, and a very uniform coating is formed on the surface of the agricultural product. This advantageous feature observed during the application of the thixotropic aqueous mixture of the present invention is due to the non-Newtonian fluid dynamics of the thixotropic mixture. In some embodiments, the thixotropic aqueous mixture is sprayed onto the surface of the agricultural product using a spray bar, and then a brush bed as described above is used to increase the complete uniformity of the coating.

[0077] Spraying may optionally be performed after the agricultural product has been immersed in the thixotropic aqueous mixture in an immersion tank and before the optional brush bed. For example, after the agricultural product has left the immersion tank and drain belt, the thixotropic aqueous mixture may be further sprayed onto the agricultural product using a spray bar located after the drain belt and before the optional brush bed.

[0078] The agricultural product may be washed in an immersion tank before the application of the thixotropic mixture. The immersion tank is typically a 10,000-liter tank used to introduce the agricultural product into the packaging line and to wash the agricultural product and remove any debris, such as leaves and branches. The advantage of using immersion tanks is that they can minimize potential damage to agricultural products during these processes. Immersion tanks and / or soaking tanks may contain mild disinfectants, such as para-acids.

[0079] These methods may further include drying (e.g., by applying heat) after applying the thixotropic aqueous mixture to the surface of the agricultural product, but more generally, allowing the mixture to air dry on the surface of the agricultural product under ambient conditions.

[0080] Coatings formed using the thixotropic aqueous mixture of the present invention are generally transparent. As used herein, the term “transparent” means a coating that allows light to pass through. Therefore, apart from the optional gloss that may distinguish the coated surface from the uncoated surface, the coating film on the surface may not be perceptible to the human eye. Thus, transparent coatings make it possible to clearly see the surface of the agricultural product through the coating. Those skilled in the art can determine whether a coating is transparent by the naked eye or by methods known in the art.

[0081] Compared to agricultural product surfaces not coated with the thixotropic aqueous mixture of the present invention (i.e., “uncoated” surfaces / “uncoated agricultural products” may have different (e.g., wax-based) coatings, or may not have any type of coating), the method of coating agricultural product surfaces with the thixotropic aqueous mixture of the present invention has been shown to improve one or more barrier properties of the agricultural product surface. For example, the method of the present invention is envisioned to form a barrier between the agricultural product surface and the external environment, reducing the transfer of gases and / or moisture through the surface compared to an uncoated surface, i.e., the method applies a layer of thixotropic aqueous mixture to the agricultural product surface, acting as a barrier against gases and / or moisture (e.g., water vapor).Therefore, applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products can reduce the transfer of gases (including oxygen and carbon dioxide) through the surface of agricultural products, thereby reducing the respiration rate of agricultural products, mitigating the effects of ethylene on the ripening of agricultural products, and / or preventing oxidation of agricultural products. Furthermore, applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products can reduce the loss of moisture (including water) through the surface of agricultural products, thereby preventing dehydration of agricultural products. Any one or more of these barrier properties can help improve the shelf life and / or best-before date of agricultural products.

[0082] In some embodiments, the thixotropic aqueous mixture and method of the present invention are used to prevent dehydration of agricultural products. Agricultural products dehydrate more rapidly under drier environmental conditions and when exposed to air / oxygen. For example, agricultural products such as fruits (e.g., pome fruits) and vegetables lose water during storage. The thixotropic aqueous mixture and related methods of the present invention can be used to reduce the permeability of water vapor through the surface of agricultural products to which the thixotropic aqueous mixture has been applied, thereby reducing moisture loss from agricultural products. As used herein, preventing agricultural products from “dehydrating” means preventing the loss of moisture (e.g., water loss) through the surface of the agricultural product. In these embodiments, “preventing” dehydration includes reducing or even avoiding dehydration. A reduction in dehydration can be defined by comparison with the dehydration of the same agricultural product uncoated with the thixotropic aqueous mixture of the present invention (i.e., the same agricultural product without any coating composition, or the same agricultural product coated with a conventional composition known in the art). Methods for observing and measuring the dehydration of agricultural products are well known in the art. For example, dehydration can be measured by weighing the agricultural product at time intervals, where a weight reduction compared to a previous weight measurement corresponds to water loss.

[0083] In some embodiments, pome fruits coated with the thixotropic aqueous mixture of the present invention show at least a 25% reduction in weight loss (e.g., at least a 30% reduction, or at least a 40% or 45% reduction) during storage at ambient temperature for 9 days, compared to the uncoated same agricultural product (control). When monitoring for longer periods, in some embodiments, pome fruits exhibit at least a 10% reduction in weight loss (e.g., at least 20%, or at least 25%) compared to uncoated pome fruits (control) stored at ambient temperature for 24 days. For example, this paper demonstrates that pears coated with any one of the eight different thixotropic hydration mixtures of the present invention showed an average reduction in weight loss of 29% to 49% (i.e., an average improvement in water retention of 29-49%) during storage at ambient temperature compared to uncoated pears. Furthermore, this paper demonstrates that apples coated with any one of the thixotropic hydration mixtures of the present invention showed an average reduction in weight loss of 11% to 27% (i.e., an average improvement in water retention of 11-27%) during storage at ambient temperature compared to uncoated apples.Therefore, the thixotropic hydrate mixture and method of the present invention provide substantial dehydration protection for pome fruits such as apples or pears.

[0084] In some embodiments, citrus fruits coated with the thixotropic hydrate mixture of the present invention exhibit at least a 10% reduction in weight loss (e.g., at least 20% or at least 25%) during storage at ambient temperature, compared to uncoated identical produce (control). When monitored for longer periods, in some embodiments, citrus fruits exhibit at least a 5% reduction in weight loss (e.g., at least 10% or at least 15%) during storage at ambient temperature, compared to uncoated identical produce (control). For example, this document demonstrates that lemons coated with various different thixotropic hydrate mixtures of the present invention exhibit an average reduction in weight loss of 24% to 28% (i.e., an average improvement in water retention of 24-28%) during storage at ambient temperature, and an average reduction in weight loss of 9% to 16% (i.e., an average improvement in water retention of 9-16%) during storage at ambient temperature, compared to uncoated lemons. Furthermore, this paper demonstrates that, compared to uncoated citrus, citrus coated with various thixotropic hydrating mixtures of the present invention exhibits an average reduction of 14% to 22% in weight loss during 3 days of storage at ambient temperature (i.e., an average improvement in water retention of 14-22%), and an average reduction of 14% to 18% in weight loss during 7 days of storage at ambient temperature (i.e., an average improvement in water retention of 14-18%). Therefore, the thixotropic hydrating mixtures and methods of the present invention provide substantial dehydration protection for citrus fruits such as lemons or citrus.

[0085] In some embodiments, the thixotropic hydrating mixtures and methods of the present invention are used to prevent the oxidation of agricultural products. Oxidation of agricultural products such as fruits (e.g., pome fruits) and vegetables leads to browning and softening. The thixotropic hydrating mixtures and related methods of the present invention can be used to reduce the permeability of oxygen to the surface of agricultural products to which the thixotropic hydrating mixture has been applied, thereby preventing the oxidation of agricultural products. As used herein, preventing the “oxidation” of agricultural products means preventing the agricultural product or its surface from being oxidized. In these embodiments, “preventing” oxidation includes reducing or even avoiding oxidation. A reduction in oxidation can be defined in comparison to oxidation of the same agricultural product not coated with the thixotropic aqueous mixture of the present invention (i.e., the same agricultural product without any coating composition, or the same agricultural product coated with a conventional composition known in the art). Methods for observing and measuring the oxidation of agricultural products are well known in the art. For example, the oxidation of agricultural products (such as browning and / or softening of agricultural products such as fruits, especially pome fruits) is typically observed and measured by the naked eye.

[0086] In some embodiments, the thixotropic aqueous mixture and method of the present invention are used to delay the ripening of agricultural products. Methods for observing and measuring ripening and overripeness of agricultural products are well known in the art.For example, the ripeness of fruits and vegetables can be observed by sight or touch. In pears, the color change from green to yellow (visual observation) is an indicator of overripeness. Ripeness can also be determined by measuring the resistance of the produce to stress (i.e., by determining firmness). It is envisioned that produce coated with the thixotropic aqueous mixture of the present invention will reach ripeness by at least 10%, 20%, or 30% compared to an uncoated control. For example, this paper demonstrates that the thixotropic aqueous mixture of the present invention delayed the ripening time of pears by about 30% compared to a control composition lacking lecithin and having a higher solids content. Compared to the uncoated control, pears coated with the thixotropic aqueous mixture of the present invention maintained an appealing green color after 7 days of storage and showed fewer signs of epidermal damage.

[0087] The shelf life of fresh produce can be defined as the length of time that a produce can be stored without affecting its use, consumption, or sale. Within the shelf life of a produce, a specific proportion of the produce maintains an acceptable level of predetermined quality under expected (or specified) conditions. Dehydration and / or oxidation of produce can reduce its shelf life. Therefore, preventing dehydration and / or oxidation of agricultural products can be used to maintain or improve the expected shelf life of agricultural products. "Improvement" in shelf life can refer to an extension of the length of time an agricultural product can be stored without affecting its use, consumption, or sale. The improvement in shelf life is achieved compared to the shelf life of the same agricultural product not coated with the thixotropic aqueous mixture of the present invention (i.e., the same agricultural product without any coating composition, or the same agricultural product coated with a conventional composition known in the art). The extension of the shelf life of an agricultural product can be measured in days or as a percentage increase in shelf life compared to a control agricultural product. For example, this document demonstrates that pome fruits (such as pears) coated with the thixotropic aqueous mixture of the present invention can have a shelf life extended by at least 4, 6, or 8 days compared to a control uncoated agricultural product.

[0088] In a fourth aspect, the present invention provides the use of any of the thixotropic aqueous mixtures of the present invention. In particular, the present invention provides the use of the thixotropic aqueous mixtures of the present invention to achieve one or more beneficial properties. In some embodiments, the present invention provides the use of the thixotropic aqueous mixture of the present invention for improving one or more barrier properties (such as gas and / or moisture barrier properties) of the surface of agricultural products compared to the barrier properties of uncoated agricultural products. In some embodiments, the present invention provides the use of the thixotropic aqueous mixture of the present invention for preventing dehydration and / or oxidation of agricultural products. In some embodiments, the present invention provides the use of the thixotropic aqueous mixture of the present invention for delaying the ripening of agricultural products. In some embodiments, the present invention provides the use of the thixotropic aqueous mixture of the present invention for extending the shelf life of agricultural products. This document defines methods for preventing dehydration and / or oxidation of agricultural products, as well as methods for determining and measuring dehydration and / or oxidation.Similarly, this document defines “maturity” and “shelf life” as well as methods for determining maturity and shelf life. The term “agricultural product” is also defined herein. In any of these uses of the invention, the thixotropic aqueous mixture can be any of the thixotropic aqueous mixtures of the invention described herein.

[0089] The thixotropic aqueous mixture used in the invention can be any of the thixotropic aqueous mixtures of the invention described herein. In some embodiments, the thixotropic aqueous mixture used in the invention comprises at least one montmorillonite clay (such as montmorillonite, lithium saponite, bentonite, or a combination of montmorillonite and lithium saponite) and lecithin. In some embodiments, the thixotropic aqueous mixture used in the invention (pages 16 / 26 of this specification, 20 CN 121240779 A) comprises montmorillonite clay, lecithin, and sodium citrate. In some embodiments, the thixotropic aqueous mixture used in the invention comprises montmorillonite clay, lecithin, PVOH, and sodium citrate; or comprises montmorillonite clay, lecithin, polysaccharides (such as xanthan gum or gum arabic), and sodium citrate. The descriptions and definitions provided herein in the context of the thixotropic aqueous mixtures of the present invention also apply to the use of the thixotropic aqueous mixtures. In particular, the montmorillonite clay and glycerophospholipids in the thixotropic aqueous mixtures used in the present invention may each be used as described in the thixotropic aqueous mixtures of the present invention, and may each be used in the amounts and / or proportions described in the context of the thixotropic aqueous mixtures of the present invention. In any use of the thixotropic aqueous mixtures containing antioxidants and / or water-soluble polymers, these components may each be used as described in the thixotropic aqueous mixtures of the present invention, and may each be used in the amounts and / or proportions described in the context of the thixotropic aqueous mixtures of the present invention.

[0090] Other Compositions and Methods of the Invention

[0091] The present invention also provides a thixotropic aqueous mixture comprising: a) montmorillonite clay; b) xanthan gum; and c) an antioxidant. This mixture is used to (suitably and effectively) prevent dehydration and / or oxidation of agricultural products, and / or delay the ripening of agricultural products, and / or extend the shelf life of agricultural products.

[0092] Any one or more montmorillonite clays may be used in this aspect of the invention. In some embodiments, the montmorillonite clay is montmorillonite, or montmorillonite and lithium montmorillonite. It is contemplated that the montmorillonite clay is present in the thixotropic aqueous mixture in amounts, for example, from 0.5 wt% to 4 wt%, optionally from 1.0 wt% to 4 wt%, optionally from 1.0 wt% to 3.5 wt%. In some embodiments, the thixotropic aqueous mixture contains 0.5 wt% to 2.5 wt%, such as 1.0 wt% to 2.0 wt%, such as 1.0 wt% to 1.5 wt% of montmorillonite. In some embodiments, the thixotropic aqueous mixture further contains 1.0 wt% to 2.5 wt%, such as 1.5 wt% to 2.0 wt% of lithium montmorillonite.Therefore, in some embodiments, the thixotropic aqueous mixture comprises: a) montmorillonite, or montmorillonite and lithium montmorillonite, in an amount of 0.5 wt% to 4 wt%, such as 1.0 wt% to 4 wt%, such as 1.0 wt% to 3.5 wt%; b) xanthan gum; and c) an antioxidant.

[0093] It is contemplated that xanthan gum is present in the thixotropic aqueous mixture in an amount of 0.2 wt% to 5.5 wt%, optionally 0.2 wt% to 0.5 wt%, or 4.5 wt% to 5.5 wt%. Therefore, in some embodiments, the thixotropic aqueous mixture comprises: a) montmorillonite clay; b) xanthan gum in an amount of 0.2 wt% to 5.5 wt%, such as 0.2 wt% to 0.5 wt% or 4.5 wt% to 5.5 wt%; and c) an antioxidant.

[0094] Therefore, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising: a) 0.5 wt% to 4 wt%, such as 1.0 wt% to 4 wt%, such as 1.0 wt% to 3.5 wt% montmorillonite clay; b) 0.2 wt% to 5.5 wt%, such as 0.2 wt% to 0.5 wt% or 4.5 wt% to 5.5 wt% xanthan gum; and c) an antioxidant. For example, the thixotropic aqueous mixture may comprise: a) 0.5 wt% to 4 wt%, such as 1.0 wt% to 4 wt%, such as 1.0 wt% to 3.5 wt% montmorillonite or montmorillonite and lithium montmorillonite; b) 0.2 wt% to 5.5 wt%, such as 0.2 wt% to 0.5 wt% or 4.5 wt% to 5.5 wt% xanthan gum; and c) an antioxidant.

[0095] In some embodiments, the ratio of at least one montmorillonite clay to xanthan gum is 10:1 to 1:3, such as 8:1 to 1:4, such as about 4:1.

[0096] The antioxidant may be sodium citrate. Thus, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising: a) montmorillonite clay; b) xanthan gum; and c) sodium citrate. For example, the thixotropic aqueous mixture may comprise: a) montmorillonite, or montmorillonite and lithium montmorillonite; b) xanthan gum; and c) sodium citrate. It is contemplated that an antioxidant (such as sodium citrate) is present in the mixture in an amount of, for example, 0.1 to 0.3% by weight, optionally about 0.2% by weight.

[0097] Therefore, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising: a) 0.5 wt% to 4 wt%, such as 1.0 wt% to 4 wt%, such as 1.0 wt% to 3.5 wt% of montmorillonite clay; b) 0.2 wt% to 5.5 wt%, such as 0.2 wt% to 0.5 wt% or 4.5 wt% to 5.5 wt% of xanthan gum; and c) 0.1 wt% to 0.3 wt%, optionally about 0.2 wt% of an antioxidant (such as sodium citrate). For example, a thixotropic aqueous mixture may contain: a) 0.5 wt% to 4 wt%, such as 1.0 wt% to 4 wt%, such as 1.0 wt% to 3.5 wt% of montmorillonite clay; b) 0.2 wt% to 5.5 wt%, such as 0.2 wt% to 0.5 wt% or 4.5 wt% to 5.5 wt% of xanthan gum; and c) 0.1 wt% to 0.3 wt%, optionally about 0.2 wt% of sodium citrate. For example, a thixotropic aqueous mixture may comprise: a) 0.5 wt% to 4 wt%, such as 1.0 wt% to 4 wt%, such as 1.0 wt% to 3.5 wt% of montmorillonite, or montmorillonite and lithium montmorillonite; b) 0.2 wt% to 5.5 wt%, such as 0.2 wt% to 0.5 wt% or 4.5 wt% to 5.5 wt% of xanthan gum; and c) 0.1 wt% to 0.3 wt%, optionally about 0.2 wt% of sodium citrate.

[0098] A total solids content of 1% to 7% solids, optionally 3.5% to 7% solids, such as about 4% solids, is contemplated in the thixotropic aqueous mixture.

[0099] A method for producing a thixotropic aqueous mixture is also provided, comprising mixing at least one montmorillonite clay, xanthan gum, and an antioxidant with water under high shear to form a thixotropic aqueous mixture. The definitions of at least one montmorillonite clay, xanthan gum, and antioxidant are the same as those given above in the context of the thixotropic aqueous mixtures of the present invention. Therefore, in some embodiments, at least one montmorillonite clay is montmorillonite, or montmorillonite and lithium montmorillonite; and / or the antioxidant is sodium citrate.

[0100] In some embodiments, at least one montmorillonite clay, xanthan gum, and / or sodium citrate are combined in powder form, and then the combined powder is mixed with water under high shear. Alternatively, during high shear mixing, at least one montmorillonite clay, xanthan gum, and sodium citrate are added to water, respectively (simultaneously or sequentially). The high shear mixing step and suitable equipment are as defined herein.

[0101] A thixotropic aqueous mixture prepared by the method of the present invention is also provided.In some embodiments, the high-shear method for manufacturing the thixotropic aqueous mixture of the present invention further includes applying the thixotropic aqueous mixture to the surface of an agricultural product.

[0102] The present invention also provides a method for preventing dehydration and / or oxidation of agricultural products, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product. A method for delaying the ripening of agricultural products is also provided, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product, thereby delaying ripening compared to ripening of agricultural products without the composition applied. A method for extending the shelf life of agricultural products is also provided, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural product, thereby extending the shelf life compared to the shelf life of agricultural products without the mixture applied. The present invention also provides corresponding uses of the thixotropic aqueous mixture of the present invention. Methods for preventing dehydration and / or oxidation of agricultural products, delaying ripening of agricultural products, and extending the shelf life of agricultural products, and methods for measuring these, are as defined herein.

[0103] In any method of the present invention, the application of the thixotropic aqueous mixture of the present invention to the surface of an agricultural product, the agricultural product and the agricultural product surface, are as defined herein. For example, the agricultural product is a fruit, optionally a pome fruit.

[0104] In any method of the invention comprising applying the thixotropic aqueous mixture of the invention to the surface of agricultural products, the mixture may be applied using an impregnation tank, a spray bar, or a brush bed, or any combination thereof; optionally, a combination of a spray bar and a brush bed, or a combination of an impregnation tank and a brush bed. For example, in some embodiments, the thixotropic aqueous mixture is applied using a spray bar at a spray rate of 1,000 to 10,000 pounds of agricultural products per liter of thixotropic aqueous mixture, optionally 5,000 to 8,000 pounds of agricultural products per liter of thixotropic aqueous mixture, optionally about 7,000 pounds of agricultural products per liter of thixotropic aqueous mixture.

[0105] Other aspects of the invention

[0106] It has been unexpectedly found that certain mixtures of water-soluble polymers, montmorillonite clay, and glycerophospholipids, when coated onto agricultural products (page 18 / 26 of specification 22 CN 121240779 A), form a highly thixotropic fluid in water, thereby increasing shelf life and best-before date more effectively than previous self-assembling coatings. Furthermore, it has been unexpectedly discovered that certain mixtures of water-soluble polymers, montmorillonite clay, and glycerophospholipids and / or polysaccharides, when coated onto agricultural products, form highly thixotropic fluids in water, increasing shelf life and best-before date. The thixotropic mixtures of the present invention form a very thin coating on agricultural products such as fruits and vegetables, extending shelf life and best-before date at much lower concentrations and dosages than previous techniques. This new formulation has a much lower percentage of solids by weight, resulting in an extremely thin coating after drying that does not alter the appearance and texture of the fruit.

[0107] In one embodiment of the invention, the mixture comprises at least one montmorillonite clay, a water-soluble polymer, and glycerophospholipids.For example, it is envisioned that the mixture is an organic thixotropic aqueous mixture for increasing the shelf life and best-before date of agricultural products, comprising at least one montmorillonite clay, a water-soluble polymer, and glycerophospholipids.

[0108] The at least one montmorillonite clay component may comprise, but is not limited to, sodium montmorillonite, lithium montmorillonite, or lithium saponite or mixtures thereof; such as sodium montmorillonite, sodium lithium montmorillonite, or lithium saponite and mixtures thereof. Envisioned water-soluble polymers include polyvinyl alcohol (PVOH), gum arabic, pullulan, and pectin or combinations thereof. In some embodiments, the water-soluble polymer is PVOH, gum arabic, or pectin, or mixtures thereof. Envisioned glycerophospholipids may include, but are not limited to, lecithin from various sources, such as soybeans, sunflowers, eggs, etc. One preferred embodiment of the composition is sodium montmorillonite, food-grade polyvinyl alcohol (PVOH), and sunflower lecithin.

[0109] In one embodiment of the invention, the coating composition comprises at least one montmorillonite clay in an amount of 0.5 w / v% to 4.5 w / v% of the total composition. In another embodiment of the coating composition of the present invention, the coating composition comprises a water-soluble polymer in an amount of 0.5 w / v% to 4.5 w / v% of the total composition. In another embodiment of the coating composition of the present invention, the coating composition comprises lecithin in an amount of 0.5 w / v% to 2.5 w / v% of the total composition. Various ratios of at least one montmorillonite clay to a water-soluble polymer are considered herein. In one embodiment, the ratio of at least one montmorillonite clay to a water-soluble polymer in the composition is 1:4 to 4:1. In another embodiment, the ratio of at least one montmorillonite clay to a water-soluble polymer in the composition is 1:1. In yet another embodiment, the aqueous dispersion of the composition is 1% to 7% solids, such as 1% to 6% solids.

[0110] This composition does not contain any components that would alter the organic state of the fruit, nor does it require additional components to achieve the desired effect. Therefore, in some embodiments, the composition described herein is a novel edible and organic composition that increases shelf life and best-before date.

[0111] The present invention also provides a method for manufacturing the thixotropic aqueous mixture of the present invention and for applying the composition to agricultural products. For example, the present invention provides a method for manufacturing a thixotropic mixture comprising at least one montmorillonite clay, glycerophospholipids, and a water-soluble polymer, and for applying said mixture to fruit. Under high-speed shear mixing, at least one montmorillonite clay, a water-soluble polymer, and glycerophospholipids are added to water, and then applied to the agricultural product via a trough, spray bar, brush bed, or a combination thereof. For example, under high-speed shear mixing, at least one montmorillonite clay, a water-soluble polymer, and food-grade lecithin are added to water, and then applied to the agricultural product via a trough, spray bar, brush bed, or a combination thereof.This method of coating agricultural products with a composition of at least one montmorillonite clay, a water-soluble polymer, and glycerophospholipids (such as lecithin) increases shelf life and optimal consumption period.

[0112] The present invention also provides a method for manufacturing a thixotropic mixture comprising at least one montmorillonite clay, glycerophospholipids, a water-soluble polymer, and / or polysaccharides, and for applying said mixture to fruit. The present invention also provides a method for applying a thixotropic mixture comprising a water-soluble polymer, montmorillonite clay, and glycerophospholipids and / or polysaccharides to form a highly oriented thin coating on the surface of fruits and vegetables to improve efficacy and extend shelf life and optimal consumption period with low dosage. In an embodiment of the present invention, the components of the composition are premixed in powder form and then added to water under high shear mixing. In another embodiment of the present invention, the components of the composition are added to water separately under high shear mixing.

[0113] The compositions of the present invention can be applied by a trough, a spray bar, a brush bed, or other methods to completely coat the agricultural products with the thixotropic mixture. Therefore, the present invention provides a method for applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products, wherein the composition is applied in an impregnation tank, a spray bar, a brush bed, or any combination thereof. In the disclosed compositions, a preferred method for applying the coating to agricultural products is a combination of a spray bar and a brush bed to increase the integrity and uniformity of the coating. Applying the coating to agricultural products using a combination of a spray bar and a brush bed during production can greatly improve efficiency and minimize coating thickness. Therefore, the present invention provides a method for applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products to increase shelf life and best-before date, wherein the composition is applied in a combination of a spray bar and a brush bed. A method for coating organic thixotropic aqueous mixtures to increase the shelf life and best-before date of agricultural products is also provided, comprising a combination of a spray bar and a brush bed. In one embodiment of the invention, fruit (such as pome fruits) is sprayed after an impregnation tank and before a brush bed. In some embodiments, the spraying rate is 1000 lb / L to 7000 lb / L of treated fruit. During the spraying stage, the shear generated by the pump and nozzle reduces the viscosity of the fluid, reducing flow resistance. Once sprayed onto the fruit surface, the viscosity recovers, forming a fairly uniform coating on the fruit. The coated fruit then passes through a brush bed, which ensures uniform coating, and the shearing action of the brush on the coating reduces its viscosity, causing the nanoclay sheets to lie parallel to the fruit surface. This action contributes to the formation of a highly oriented, self-assembled barrier coating with extremely high efficacy.

[0114] The method of applying the coating composition to the fruit can be carried out before or after harvest. Applying the coating before harvest yields the greatest effect, but applying it after storage also provides substantial benefits for shelf life and optimal consumption period.

[0115] The present invention utilizes the thixotropy of the self-assembled coating and the high aspect ratio of the nanoclay contained therein.

[0116] The terms “comprising,” “including,” and “having” as used in the claims and specification herein shall be considered as indicating an open group that may include other unspecified elements. The terms “an,” “a,” and singular forms of words shall be considered as plural forms that include the same words, such that these words imply the provision of one or more of something. The terms “a” or “single” may be used to indicate that something exists only once. Similarly, other specific integer values, such as “two,” may be used when a particular quantity of things is intended. The terms “preferred,” “ideally,” “preferred,” “optionally,” “may,” and similar terms are used to indicate that the mentioned items, conditions, or steps are optional (non-essential) features of the invention.

[0117] The present invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while maintaining the spirit and scope of the invention. It will be apparent to those skilled in the art that, in addition to the methods, apparatuses, apparatus elements, materials, procedures, and techniques specifically described herein, the practices of the invention as broadly disclosed herein can also be applied without undue experimentation. This invention is intended to cover all known functional equivalents of the methods, apparatuses, apparatus elements, materials, procedures, and techniques described herein. All sub-scopes and individual values ​​are intended to be included within the scope of this disclosure. This invention is not limited to the disclosed embodiments, but includes any embodiments illustrated in the drawings or exemplified in the description, which are merely illustrative and not limiting.

[0118] While the invention has been described with respect to a limited number of embodiments, those skilled in the art will understand, upon understanding the disclosure of this invention, that other embodiments can be devised without departing from the scope of this invention. Therefore, the scope of this invention should be limited only by the appended claims.

[0119] All references in this application, such as patent documents, including issued or authorized patents or equivalents, patent application publications, and non-patent documents or other original materials, are incorporated herein by reference in their entirety, as if individually incorporated by reference, provided that each reference does not contradict at least part of the disclosure in this application (e.g., partially contradictory references are incorporated by reference except for the non-contradictory parts of the specification 20 / 26 pages 24 CN 121240779 A in the middle of the reference).

[0120] Examples

[0121] Example 1: Thixotropic composition for extending the shelf life of D'Anjou pear

[0122] A laboratory-scale test was conducted in which a control self-assembled composition was compared with the thixotropic composition of the present invention.The control composition had a total solids content of 7.4% by weight, consisting of 1.2% lithium saponite, 1.5% montmorillonite, 4.2% polyvinyl alcohol (PVOH), and 0.5% sodium citrate. The composition of the present invention had a total solids content of 5.5% by weight, containing 0.576% lithium saponite, 0.72% montmorillonite, 2.0% lecithin (from sunflower), 2.02% PVOH, and 0.252% sodium citrate. Anjou pears were coated with both formulations using a spray gun at the same spray volume. The pears were then monitored for a green-to-yellow transition. This color change indicates overripeness. The control coating lasted for 10 days, while the fruit coated with the composition of the present invention lasted for 13 days. This represents a 30% increase in shelf life compared to the control coating using a formulation with 26% less solids.

[0123] Example 2: Application of a thixotropic composition to extend the shelf life of Bartlett pears

[0124] A thixotropic composition containing montmorillonite, lithium saponite, polyvinyl alcohol, and lecithin was applied to pears in two ways. The first was by immersion tank, and the second was a combination of a spray bar and a brush bed. In the tests, color change and pressure measurements were used to determine the amount of coating per liter of fruit and the amount of shelf-life extension. The pears used in the tests were Bartlett pears. For fruit coated by immersion tank, the dosage ratio was determined to be 500 pounds of fruit per liter. The shelf life was extended by six days compared to the control pears without any coating. For pears coated by the combination of the spray bar and brush bed, the optimal dosage ratio was 7000 pounds per liter. The shelf life was extended by eight days compared to the uncoated control.

[0125] Example 3: Extending the shelf life of Argentine Packham Triumph pears

[0126] In this example, Argentine Packham Triumph pears, a common pear variety, were coated by immersion in a 4.5% thixotropic aqueous dispersion containing 0.945% bentonite, 1.48% polyvinyl alcohol, 1.89% lecithin, and 0.18% sodium citrate. The pears were stored at room temperature for seven days. The color change of the coated fruit was delayed, which is related to ripening. Figure 1 shows that, compared with the uncoated control, the coated pears retained their appealing green color better and showed fewer signs of damage on the skin.

[0127] Example 4: Thixotropic coating to prevent dehydration of Gala apples

[0128] Tests were conducted to measure the effect of changes in the composition of the thixotropic mixture of the present invention on improving the shelf life of coated Gala apples. In this experiment, 13 different thixotropic aqueous mixtures containing various proportions of montmorillonite (MMT), lithium montmorillonite, lecithin, xanthan gum, and citrate were used to coat organic Gala apples. The mixtures were applied manually to simulate high-shear spraying and brush beds. The composition of mixtures S1 to S13 is detailed in Table 1.

[0129] Table 1: Specification 21 / 26 pages 25 CN 121240779 A

[0130] After 24 days, the apples were weighed to assess fruit dehydration, which led to spoilage. The average weight of each apple sample is summarized in Table 2 and Figure 2. Compared with the uncoated control, the water retention of apples coated with one of the 13 mixtures was improved by an average of 11%-27%. The samples with the highest improvement in water retention were S7 and S11.

[0131] Table 2: Specification 22 / 26 pages 26 CN 121240779 A

[0132] Example 5: Thixotropic coating for preventing dehydration of Bartlett pears

[0133] Tests were conducted to measure the effect of changes in the composition of the thixotropic mixtures of the present invention on improving the shelf life of coated Bartlett pears. In this experiment, eight different thixotropic aqueous mixtures containing various proportions of montmorillonite (MMT), lecithin, gum arabic, and citrate were used to coat Bartlett pears. The mixtures were applied manually to simulate high-shear spraying and brush bed application methods. The composition of mixtures S14 to S23 is detailed in Table 3.

[0134] Table 3:

[0135] After 4, 7, and 9 days, the pears were weighed to assess fruit dehydration, which leads to spoilage. The average weight of each Bartlett pear sample is summarized in Table 4 and Figure 3. After 9 days, the water retention of pears coated with one of the eight mixtures improved by an average of 29%–49% compared to the uncoated control. The samples with the highest improvement in water retention percentage compared to the control were S21 and S22.

[0136] Table 4:

[0137] Example 6: Thixotropic coating for preventing lemon dehydration, instruction manual 23 / 26 pages 27 CN 121240779 A

[0138] Tests were conducted to measure the effect of changes in the composition of the thixotropic mixtures of the present invention on improving the shelf life of coated lemons. In this test, four different thixotropic aqueous mixtures containing various proportions of montmorillonite (MMT), lecithin, citrate, and xanthan gum or gum arabic were used to coat lemons. The composition of mixtures S2 and S24-S26 is detailed in Table 5.

[0139] Table 5:

[0140] After 3, 5, and 7 days, the lemons were weighed to assess fruit dehydration, which leads to spoilage. The average weight of each lemon sample is summarized in Table 6 and Figure 4. Lemons coated with one of the four mixtures showed an average improvement in water retention of 24%–27.5% compared to the uncoated control after 3 days, and an average improvement of 9%–13% compared to the uncoated control after 7 days. The sample with the highest improvement in water retention was S2.

[0141] Table 6:

[0142] The tests were also conducted on lemons coated with a thixotropic composition containing montmorillonite, optionally lithium soapstone (LAP), PVOH, lecithin, and citrate; the formulations of compositions S27 and S28 are detailed in Table 7.

[0143] Table 7:

[0144] After 3, 5, and 7 days, the lemons were weighed to assess fruit dehydration. The average weight of each lemon sample is summarized in Table 8 and Figure 5. Lemons coated with one of the two mixtures showed an average improvement in water retention of 26%–27.5% compared to the uncoated control after 3 days, and an average improvement of 11%–16% compared to the uncoated control after 7 days. The sample with the highest improvement in water retention was S27.

[0145] Table 8: Specification 24 / 26 pages 28 CN 121240779 A

[0146] Example 7: Thixotropic coating for preventing citrus dehydration

[0147] Tests were conducted to measure the effect of changes in the composition of the thixotropic mixtures of the present invention on improving the shelf life of coated citrus. In this test, four different thixotropic aqueous mixtures containing various proportions of montmorillonite (MMT), lecithin, citrate, and xanthan gum or gum arabic were used to coat citrus. The composition of mixtures S2, S24, S26, and S29 is detailed in Table 9.

[0148] Table 9:

[0149] The citrus fruits were weighed after 3, 5, and 7 days to assess fruit dehydration. The average weight of each citrus sample is summarized in Table 10 and Figure 6. Citrus fruits coated with one of the two mixtures showed an average improvement in water retention of 14%–19% compared to the uncoated control after 3 days, and an average improvement of 14%–18% compared to the uncoated control after 7 days. The sample with the highest improvement in water retention was S2.

[0150] Table 10:

[0151] The tests were also conducted on citrus fruits coated with thixotropic compositions S27 and S28, the formulation of which is detailed in Table 7 for the lemon coating. The citrus fruits were weighed after 3, 5, and 7 days to assess fruit dehydration. The average weight of each citrus sample is summarized in Table 11 and Figure 7. Citrus fruits coated with one of the two mixtures showed an average improvement in water retention of 19%-22% compared to the uncoated control after 3 days, and an average improvement of 14%-15% compared to the uncoated control after 7 days. The sample with the highest improvement in water retention was S27.

[0152] Table 11: Specification 25 / 26 pages 29 CN 121240779 A

[0153] Example 8: Thixotropic coating to prevent cherry dehydration

[0154] In this test, cherries were coated with three thixotropic mixtures containing various proportions of montmorillonite (MMT), xanthan gum, lecithin, and citrate. The composition of mixtures S30 and S31 is detailed in Table 12.

[0155] Specification 26 / 26 pages 30 CN 121240779 A Figure 1 Specification Figure 1 / 7 pages 31 CN 121240779 A Figure 2 Specification Figure 2 / 7 pages 32 CN 121240779 A Figure 3 Specification Figure 3 / 7 pages 33 CN 121240779 A Figure 4 Specification Figure 4 / 7 pages 34 CN 121240779 A Figure 5 Specification Figure 5 / 7 pages 35 CN 121240779 A Figure 6 Specification Figure 6 / 7 pages 36 CN 121240779 A Figure 7 Specification Figure 7 / 7 pages 37 CN 121240779 A.

Claims

1. A thixotropic aqueous mixture for use in preventing dehydration and / or oxidation of an agricultural product, comprising: a) a smectite clay; and b) a glycerophospholipid.

2. The thixotropic aqueous mixture of claim 1, wherein the smectite clay is montmorillonite, hectorite, or bentonite, or is montmorillonite and hectorite.

3. The thixotropic aqueous mixture of claim 1 or 2, wherein the glycerophospholipid is lecithin; optionally, wherein the lecithin is or is derived from soy lecithin, sunflower lecithin, or egg lecithin.

4. The thixotropic aqueous mixture of any one of claims 1-3, wherein the smectite clay is present in the thixotropic aqueous mixture in an amount of 0.5 wt% to 6.5 wt%, optionally 1.0 wt% to 5.0 wt%, optionally 1.0 wt% to 1.5 wt%.

5. The thixotropic aqueous mixture of any one of claims 1-4, wherein the glycerophospholipid is present in the thixotropic aqueous mixture in an amount of 0.5 wt% to 4.0 wt%, optionally 1.5 wt% to 3.5 wt%, optionally 1.5 wt% to 2.5 wt%.

6. The thixotropic aqueous mixture of any one of claims 1-5, wherein the ratio of the smectite clay to the glycerophospholipid is 3: 1 to 0.3: 1 (w / w), optionally 1.5: 1 to 0.5: 1, or 1: 1 to 0.5: 1; optionally about 0.7: 1 (w / w).

7. The thixotropic aqueous mixture of any one of claims 1-6, further comprising an antioxidant; optionally wherein the antioxidant is sodium citrate.

8. The thixotropic aqueous mixture of claim 7, wherein the antioxidant is present in the mixture in an amount of 0.05 wt% to 0.5 wt%; optionally 0.1 wt% to 0.3 wt%.

9. The thixotropic aqueous mixture of claim 7 or 8, comprising: a) a smectite clay; b) lecithin; and c) sodium citrate.

10. The thixotropic aqueous mixture of any one of claims 1-9, further comprising a water-soluble polymer.

11. The thixotropic aqueous mixture of claim 10, wherein the water-soluble polymer is PVOH.

12. The thixotropic aqueous mixture of claim 11, comprising: a) a smectite clay; b) lecithin; c) PVOH; and d) sodium citrate.

13. The thixotropic aqueous mixture of claim 12, wherein the smectite clay is bentonite, hectorite, or montmorillonite and hectorite.

14. The thixotropic aqueous mixture of any one of claims 11-13, wherein the PVOH is present in the mixture in an amount of 1.0 wt% to 3.0 wt%, optionally 1.5 wt% to 2.5 wt%, optionally about 2.0 wt%.

15. The thixotropic aqueous mixture of claim 10, wherein the water-soluble polymer comprises one or more polysaccharides.

16. The thixotropic aqueous mixture of claim 15, wherein the polysaccharide is xanthan gum or gum arabic.

17. The thixotropic aqueous mixture of claim 16, comprising: a) a smectite clay; b) lecithin; c) xanthan gum or gum arabic; and d) sodium citrate.

18. The thixotropic aqueous mixture of claim 17, wherein the smectite clay is montmorillonite or hectorite.

19. The thixotropic aqueous mixture of any one of claims 15-18, wherein the one or more polysaccharides are present in the mixture in an amount of 0.2 wt% to 6.5 wt%; optionally, wherein xanthan gum is present in the mixture in an amount of 0.2 wt% to 0.6 wt%; optionally, wherein gum arabic is present in the mixture in an amount of 0.2 wt% to 2.0 wt%, optionally 0.5 wt% to 2.0 wt%.

20. The thixotropic aqueous mixture of any one of claims 1-19, wherein the total solids content of the thixotropic aqueous mixture is 2% to 10% solids, optionally 3% to 6% solids, optionally 3.5% to 5.5% solids.

21. A method of manufacturing a thixotropic aqueous mixture, comprising mixing at least one smectite clay and a glycerophospholipid with water under high shear to form a thixotropic aqueous mixture.

22. The method of claim 21, wherein: the at least one smectite clay is montmorillonite, hectorite, bentonite, or montmorillonite and hectorite; and / or the glycerophospholipid is lecithin.

23. The method of claim 21 or 22, wherein: the at least one smectite clay and the glycerophospholipid are combined in powder form, and then the combined powder is mixed with the solvent under high shear; or the at least one smectite clay and the glycerophospholipid are added separately to the water during the high shear mixing process.

24. The method of any one of claims 21-23, further comprising mixing sodium citrate with the smectite clay, glycerophospholipid, and water under high shear.

25. The method of any one of claims 21-23, further comprising mixing a water-soluble polymer with the smectite clay, glycerophospholipid, and water under high shear; optionally wherein the water-soluble polymer is PVOH or a polysaccharide.

26. A thixotropic mixture manufactured according to the method of any one of claims 21-25.

27. A method comprising: i) manufacturing a thixotropic aqueous mixture according to the method of any one of claims 21-25 using high shear; and ii) applying the thixotropic aqueous mixture to the surface of an agricultural product.

28. A method of preventing dehydration and / or oxidation of an agricultural product, comprising applying the thixotropic aqueous mixture of any one of claims 1-20 or 26 to the surface of an agricultural product.

29. A method of delaying ripening of an agricultural product, comprising applying the thixotropic aqueous mixture of any one of claims 1-20 or 26 to the surface of an agricultural product, thereby delaying ripening of the agricultural product compared to ripening of an uncoated agricultural product.

30. The method of any one of claims 27-29, wherein the thixotropic aqueous mixture is applied to the surface of the produce using an immersion tank, a spray bar, or a brush bed, or any combination thereof; optionally, wherein the thixotropic aqueous mixture is applied using a combination of a spray bar and a brush bed, or using a combination of an immersion tank and a brush bed; optionally, wherein the thixotropic aqueous mixture is applied using a spray bar at a spray rate of 1000 to 10000 pounds of produce per liter of thixotropic aqueous mixture; optionally 5000 to 8000 pounds of produce per liter of thixotropic aqueous mixture; optionally about 7000 pounds of produce per liter of thixotropic aqueous mixture.

31. Use of the thixotropic aqueous mixture of any one of claims 1-20 or 26 for preventing dehydration and / or oxidation of produce.

32. Use of the thixotropic aqueous mixture of any one of claims 1-20 or 26 for delaying ripening of produce.

33. The method of any one of claims 27-30, or the use of claim 31 or 32, wherein the produce is fruit, optionally stone fruit or citrus fruit.

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