Improved barrier coating for agricultural products

Abstract

A thixotropic aqueous mixture is provided, which forms a very thin coating on fruits and vegetables, extending their shelf life and shelf life at much lower concentrations and doses than conventional techniques. The mixture comprises at least one smectite clay and glycerophospholipid, as well as optionally a water-soluble polymer, and is added to water by high-shear mixing and then applied to agricultural products via tanks, spray bars, or brush beds or a combination thereof.

Description

Technical Field

[0001] The present invention generally relates to compositions for increasing the storage life and eating-ripe period of agricultural products such as fruits and vegetables. The composition forms a coating on the surface of the agricultural product that improves one or more barrier properties, particularly the gas barrier effect, of the surface of the agricultural product compared to uncoated agricultural products, thereby protecting the agricultural product from dehydration and / or oxidation that would otherwise reduce the storage life and eating-ripe period of the agricultural product. The present invention also relates to methods of manufacturing the composition. The present invention further provides a method for coating agricultural products (such as fruits), including applying the coating composition to the agricultural product, as well as methods and uses for improving the effectiveness of the barrier coating for extending the storage life of coated fruits and vegetables.

Background Art

[0002] Fruits and vegetables have the problem that their storage life and eating-ripe period are limited, which is affected by dehydration and exposure to oxygen in the air. Climacteric fruits including apples, pears, and avocados continue to ripen after harvest. The production of ethylene, combined with an increased respiration rate, contributes to faster ripening, thereby reducing the storage life and eating-ripe period. Fruits and vegetables are often stored for long periods and are often transported long distances before reaching the final point of sale to consumers. This can pose problems when the agricultural products ripen early. Overripe or damaged fruits and vegetables often cannot be sold or consumed, resulting in large amounts of food waste. Therefore, it is desirable to improve the storage life of agricultural products by increasing the length of time they can be stored before consumption and by preventing premature ripening, damage, and / or spoilage of the agricultural products.

[0003] One approach to reducing dehydration is the use of wax to coat fruits. Fruits and vegetables are commonly coated with wax or shellac to give them a glossy sheen and retain moisture. This technique is widely used for apples, avocados, and cucumbers. These traditional coatings do not improve the shelf life of produce and offer little protection against oxidation. Wax coatings also act as carriers for fungicides and pesticides applied to produce, potentially causing undesirable tastes and textures in produce (especially fruits), which can be unpleasant for consumers. Wax coatings are not easily removed from the surface of produce by consumers and can accumulate on packaging lines.

[0004] It has recently been demonstrated that coating fruits with an aqueous mixture of selected smectite clay and a suitable polymer self-assembles into a nanocomposite barrier coating on the surface of fruits or vegetables. This coating does an excellent job of protecting fruits from oxidation and dehydration. When applied to fruits via a dip tank, these self-assembling barrier coatings result in a good extension of shelf life, doubling or tripling the shelf life of agricultural products. However, this approach requires high concentrations and doses of the coating on the fruit, which can result in very poor anaerobic conditions for fruit taste and ripening. Higher concentrations also present application problems due to viscosity. These thick coatings can separate and peel off from the fruit. They are also quite expensive.

[0005] Therefore, there is a need in the art for additives that improve the effectiveness of these barrier coatings at much lower concentrations and doses, and for thinner barrier coatings that extend the shelf life of agricultural products. [Overview of the project]

[0006] The present invention generally relates to compositions, methods and uses for protecting agricultural products from dehydration and / or oxidation, 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 compositions and mixtures of the present invention that are thixotropic.

[0007] According to a first aspect of the present invention, a thixotropic aqueous mixture for protecting agricultural products from dehydration and / or oxidation is provided, comprising a) smectite clay and b) glycerophospholipid.

[0008] The present invention also provides a method for producing a thixotropic aqueous mixture and a thixotropic aqueous mixture produced by the method of the present invention. The method of the present invention generally includes at least one mixing step carried out under high shear. Accordingly, according to a second aspect of the present invention, a method for producing a thixotropic aqueous mixture is provided, comprising mixing at least one smectite clay and a 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 an agricultural product.

[0009] By applying a coating of the thixotropic aqueous mixture of the present invention to the surface of agricultural products, one or more of the advantageous properties described herein are imparted. In this regard, coating the surface of agricultural products with the thixotropic aqueous mixture of the present invention improves one or more of the barrier properties of the agricultural product surface compared to an uncoated agricultural product surface. For example, coating the surface of agricultural products with the thixotropic aqueous mixture of the present invention is expected to form a barrier between the agricultural product surface and the external environment, reducing the movement of gases and / or moisture across the surface compared to an uncoated surface, thereby reducing oxidation, respiration, transpiration, moisture loss, and / or dehydration. Any one or more of these barrier properties may contribute to improving the shelf life and / or shelf life of agricultural products.

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

[0011] The present invention also provides the use of the thixotropic aqueous mixture of the present invention. Accordingly, in a fifth aspect, the present invention provides the use of the thixotropic aqueous mixture of the present invention for protecting agricultural products from dehydration and / or oxidation, and further provides the use of the thixotropic aqueous mixture of the present invention for delaying the ripening of agricultural products. [Brief explanation of the drawing]

[0012] [Figure 1]Figure 1 shows photographs illustrating the degree of ripening (change from green to pale yellow) observed on day 7 after application in Argentine Paccam pears coated with a 4.5% aqueous dispersion of thixotropy containing 0.945% bentonite, 1.48% polyvinyl alcohol, 1.89% lecithin, and 0.18% sodium citrate, compared to uncoated "control" Argentine Paccam pears (top photo). The coated pears can be observed to retain their attractive green color better and show fewer signs of skin damage compared to the uncoated control pears.

[0013] [Figure 2] Figure 2 shows the weight loss percentage of organic apples coated with the thixotropic coating of the present invention compared to "control" apples (uncoated) 24 days after application. When apples are coated with the thixotropic aqueous mixture of the present invention, a significant reduction in weight loss percentage can be observed compared to uncoated apples of the same type.

[0014] [Figure 3] Figure 3 shows the weight loss percentage of conventional (i.e., non-organic) Bartlett pears coated with the thixotropic coating of the present invention compared to "control" Bartlett pears (uncoated) on day 9 after application. When pears are coated with the thixotropic aqueous mixture of the present invention, a significant reduction in weight loss percentage can be observed compared to uncoated pears of the same type.

[0015] [Figure 4] Figure 4 shows the weight loss percentage of lemons coated with the thixotropic coating of the present invention compared to "control" lemons (uncoated) on day 7 after application. When lemons are coated with the thixotropic aqueous mixture of the present invention, a significant reduction in weight loss percentage can be observed compared to uncoated lemons.

[0016] [Figure 5] Figure 5 shows the weight loss percentage of lemons coated with the thixotropic coating of the present invention compared to "control" lemons (uncoated) on day 7 after application. When lemons are coated with the thixotropic aqueous mixture of the present invention, a significant reduction in weight loss percentage can be observed compared to uncoated lemons.

[0017] [Figure 6] Figure 6 shows the weight loss percentage of mandarins coated with the thixotropic coating of the present invention compared to "control" mandarins (uncoated) on day 7 after application. When mandarins are coated with the thixotropic aqueous mixture of the present invention, a significant reduction in weight loss percentage can be observed compared to uncoated mandarins.

[0018] [Figure 7] Figure 7 shows the weight loss percentage of mandarins coated with the thixotropic coating of the present invention compared to "control" mandarins (uncoated) on day 7 after application. When mandarins are coated with the thixotropic aqueous mixture of the present invention, a significant reduction in weight loss percentage can be observed compared to uncoated mandarins. [Modes for carrying out the invention]

[0019] The following detailed description is provided to enable those skilled in the art to construct and use the present invention. For illustrative purposes, specific details are given to provide a complete understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to carry out the present invention. Descriptions of specific uses are provided only as representative examples. Various modifications to preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and uses without departing from the scope of the present invention. The present invention is not intended to be limited to the embodiments shown, but rather to provide the broadest possible scope consistent with the principles and features disclosed herein.

[0020] When the surface of agricultural products (e.g., the skin, hull or pericarp of agricultural products) is coated with the thixotropic aqueous mixture of the present invention, it has been unexpectedly discovered that one or more barrier properties of the surface of the agricultural products are improved as compared to the surface of agricultural products not coated with the thixotropic aqueous mixture of the present invention (i.e., the "uncoated" surface / "uncoated agricultural products"). As used herein, the term "uncoated" encompasses surfaces lacking a coating, as well as surfaces coated with conventional barrier coatings such as wax-based coatings. Thus, the surface of agricultural products not coated with the thixotropic aqueous mixture of the present invention (i.e., "uncoated") may have different coatings or may have no coatings of any kind. For example, when the surface of agricultural products is coated with the thixotropic aqueous mixture of the present invention, it is envisioned that a barrier is formed between the surface of the agricultural products and the external environment, reducing the movement of gas and / or moisture through the surface as compared to an uncoated surface. Thus, when applied to the surface of agricultural products, the thixotropic aqueous mixture of the present invention can act as a gas and / or moisture (e.g., water vapor) barrier. By reducing the movement 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 slow the effect of ethylene on the ripening of agricultural products. By reducing the movement of atmospheric oxygen through the surface of agricultural products, the thixotropic aqueous mixture of the present invention can protect agricultural products from oxidation. Further, by reducing the loss of moisture, including water, through the surface of agricultural products, the thixotropic aqueous mixture of the present invention can protect agricultural products from transpiration and / or dehydration. Any one or more of these barrier properties can contribute to an improvement in the storage life and / or eating-ripe period of agricultural products.

[0021] In a first aspect, the present invention provides a thixotropic aqueous mixture comprising a) a smectite clay, and b) a glycerophospholipid.

[0022] Thixotropic aqueous mixtures are intended to protect agricultural products from dehydration and / or oxidation (they are suitable and effective at protecting). Thixotropic aqueous mixtures are also intended to slow down the ripening of agricultural products coated with the mixture compared to uncoated agricultural products (they are suitable and effective at slowing down ripening). Furthermore, thixotropic aqueous mixtures are intended to maintain or extend the shelf life of agricultural products coated with the mixture compared to uncoated agricultural products (they are suitable and effective at maintaining or extending shelf life). Thixotropic aqueous mixtures are also intended to form a barrier coating on the surface of agricultural products (they are suitable and effective at forming barrier coatings), and improve one or more barrier properties (e.g., gas barrier properties) of the surface of agricultural products to which the thixotropic aqueous mixture is applied compared to an uncoated surface of the same (kind) agricultural product. Thus, thixotropic aqueous mixtures may be called coating compositions, and optionally, barrier coating compositions such as gas barrier coating compositions and / or moisture barrier coating compositions. When applied to the surface of agricultural products, the thixotropic aqueous mixture of the present invention forms a coating that acts as a barrier against the movement of gases and / or moisture through the surface of agricultural products. Therefore, the coating of the thixotropic aqueous mixture of the present invention may be referred to as a barrier coating, such as a gas barrier coating and / or moisture barrier coating.

[0023] As used herein, the term "thixotropy" refers to a mixture having non-Newtonian hydrodynamics such as flow characteristics that vary with apparent viscosity, shear rate, and shear duration. The thixotropy of an aqueous mixture is important for achieving one or more of the desired barrier properties when coated on the surface of an agricultural product, thereby protecting it from dehydration and / or oxidation. The high shear applied during the preparation of the mixture and / or during the application of the mixture to the surface of the agricultural product reduces the viscosity of the thixotropic aqueous mixture and the flow resistance. For example, when spraying a coating mixture onto the surface of an agricultural product using a spray bar, the shear applied by the pump and spray nozzles reduces the viscosity of the aqueous thixotropic mixture and the flow resistance during spraying (i.e., the thixotropic mixture is thinned when dispensed through the spray nozzles). Using a high shear application method, the amount of agricultural product that can be coated using a defined volume of the mixture is much greater than the amount of agricultural product that can be coated with the same volume of the mixture using a non-high shear method such as dipping. For example, using 1 liter of the thixotropic aqueous mixture of the present invention, 500 pounds of agricultural product can be coated when applied via a dip tank, whereas up to 7000 pounds of agricultural product can be coated when applied via a spray bar. When the spray hits the surface of the agricultural product, the viscosity of the thixotropic aqueous mixture recovers and the thixotropic aqueous mixture forms a coating or film on the surface of the agricultural product. A brush bed can be used to further smooth the coating on the surface of the agricultural product and make the coating more comprehensive. Further, brushing reorients the platelets of the smectite clay to be parallel to the surface of the agricultural product (i.e., aligned with the surface of the agricultural product), which strengthens the coating.

[0024] The thixotropic aqueous mixture of the present invention contains smectite clay. Any smectite clay can be used in the thixotropic aqueous mixture of the present invention. For example, the smectite clay may be montmorillonite, bentonite, hectorite, or laponite (lithium sodium magnesium silicate, Na 0.7 Si8Mg 5.5 Li 0.3 O 20 It is assumed that the material is (OH)4), or at least one of any combination thereof. Particularly good results have been achieved using montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises montmorillonite and / or laponite. In some embodiments, the thixotropic aqueous mixture of the present invention comprises bentonite. When dispersed in water, the smectite clay forms a colloidal dispersion which may be translucent or transparent.

[0025] Smectite clay is assumed to be present in the thixotropic aqueous mixture in an amount of, for example, 0.5 to 6.5% by weight, optionally 1.0 to 5.0% by weight, or optionally 1.0 to 1.5% by weight. Accordingly, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, or for example 1.0 to 1.5% by weight, and b) glycerophospholipids. For example, in some embodiments, the thixotropic aqueous mixture comprises a) smectite clay in an amount of about 1.0 to 1.5% by weight, and b) glycerophospholipids. In any of these embodiments, the smectite clay may be montmorillonite, laponite, or bentonite, or montmorillonite and laponite.

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

[0027] Glycerophospholipids (e.g., lecithin) are assumed to be present in the thixotropic aqueous mixture in amounts of, for example, 0.5 to 4.0% by weight, optionally 1.5 to 3.5% by weight, optionally 1.5 to 2.5% by weight, and optionally 2% by weight (or about 2% by weight). Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention contains a) smectite clay and b) glycerophospholipids in amounts of, for example, 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, and for example about 2% by weight. In some embodiments, the thixotropic aqueous mixture of the present invention contains a) smectite clay and b) lecithin in amounts of, for example, 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, and for example about 2% by weight. For example, in some embodiments, the thixotropic aqueous mixture of the present invention comprises a) smectite clay and b) lecithin in an amount of about 2% by weight.

[0028] Therefore, the thixotropic aqueous mixture of the present invention is assumed to contain a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight, and b) glycerophospholipid in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight. For example, the thixotropic aqueous mixture of the present invention may contain a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight, and b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight. In some embodiments, the thixotropic aqueous mixture of the present invention comprises a) 1.0 to 1.5% by weight of smectite clay and b) about 2% by weight of glycerophospholipid (e.g., lecithin). In any of these embodiments, the smectite clay may be montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite.

[0029] In some embodiments, the ratio of smectite clay to glycerophospholipid (e.g., lecithin) is 3:1 to 0.3:1 (w / w), optionally 3:1 to 1:1, for example about 1.4:1, or optionally 1.5:1 to 0.5:1 (w / w), for example 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 smectite clay:lecithin in a ratio of about 0.7:1.

[0030] The thixotropic aqueous mixture may further contain an antioxidant. The inclusion of an antioxidant is useful when it is desirable to limit the oxidation of agricultural products. In some embodiments, the antioxidant is sodium citrate or contains sodium citrate. Sodium citrate also acts as a useful anti-flocculation agent when preparing the mixture using hard water that floccates the coating. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises smectite clay, glycerophospholipid, and sodium citrate. For example, the thixotropic aqueous mixture may contain smectite clay, lecithin, and sodium citrate.

[0031] Antioxidants, optionally sodium citrate, are assumed to be present in any of the thixotropic aqueous mixtures of the present invention in an amount of 0.05 to 0.5% by weight, optionally 0.1 to 0.3% by weight, or optionally (or about) 0.2 or 0.25% by weight.

[0032] Therefore, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) glycerophospholipid in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) antioxidant in an amount of 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example about 0.2 or 0.25% by weight. For example, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) an antioxidant in an amount of 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example about 0.2 or 0.25% by weight. For example, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) sodium citrate in an amount of 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example about 0.2 or 0.25% by weight. In some embodiments, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 1.0 to 1.5% by weight; b) lecithin in an amount of about 2% by weight; and sodium citrate in an amount of about 0.2 or 0.25% by weight. In any of these embodiments, the smectite clay may be montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite.

[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 to 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 further contain one or more water-soluble polymers. Suitable water-soluble polymers to be included in the thixotropic aqueous mixture 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 mixture of the present invention contains PVOH. For example, the thixotropic aqueous mixture of the present invention may contain a) smectite clay, b) lecithin, and c) PVOH. In some embodiments, the thixotropic aqueous mixture of the present invention may contain a) smectite clay, b) lecithin, c) PVOH, d) an antioxidant, and optionally, sodium citrate. For example, the thixotropic aqueous mixture of the present invention may contain a) laponite, b) lecithin, c) PVOH, and d) sodium citrate, for example, a) montmorillonite and laponite, 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] PVOH is assumed to be present in any of the thixotropic aqueous mixtures of the present invention in an amount of 1.0 to 3.0% by weight, optionally 1.5 to 2.5% by weight, and optionally about 2.0% by weight. Therefore, in some embodiments, the thixotropic aqueous mixture of the present invention comprises a) smectite clay, b) glycerophospholipid, and c) PVOH in an amount of 1.0 to 3.0% by weight, for example, 1.5 to 2.5% by weight, or for example, about 2.0% by weight. For example, the thixotropic aqueous mixture of the present invention may comprise a) smectite clay, b) lecithin, and c) PVOH in an amount of 1.0 to 3.0% by weight, for example, 1.5 to 2.5% by weight, or for example, about 2.0% by weight. In any of these embodiments, the thixotropic aqueous mixture of the present invention may further contain an antioxidant such as sodium citrate.

[0037] Therefore, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) glycerophospholipid in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) PVOH in an amount of 1.0 to 3.0% by weight, for example 1.5 to 2.5% by weight, for example about 2.0% by weight. For example, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) PVOH in an amount of 1.0 to 3.0% by weight, for example 1.5 to 2.5% by weight, for example about 2.0% by weight. For example, the thixotropic aqueous mixture of the present invention may contain a) 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight of smectite clay; b) 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight of lecithin; c) 1.0 to 3.0% by weight, for example 1.5 to 2.5% by weight, for example about 2.0% by weight of PVOH; and d) 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example 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 smectite clay, b) about 2% by weight of lecithin, c) about 2.0% by weight of PVOH, and about 0.2 or 0.25% by weight of sodium citrate. In any of these embodiments, the smectite clay may be montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite.

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

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

[0040] In other embodiments, the water-soluble polymer is a naturally occurring water-soluble polymer. As used in this context, the terms “natural” or “naturally occurring” refer to a water-soluble polymer that is naturally occurring or derived from nature and not produced or caused by the human species. The term does not require the polymer to be “directly obtained from nature.” A “natural” or “naturally occurring” water-soluble substance may, but is not required to be, naturally identical. Examples of naturally occurring water-soluble polymers useful in this invention include polysaccharides.

[0041] In some embodiments, the thixotropic aqueous mixture of the present invention contains a polysaccharide. For example, the thixotropic aqueous mixture of the present invention may contain a) smectite clay, b) lecithin, and c) a polysaccharide. In some embodiments, the thixotropic aqueous mixture of the present invention may contain a) smectite clay, b) lecithin, c) a polysaccharide, d) an antioxidant, and optionally sodium citrate.

[0042] Examples of polysaccharides suitable for inclusion in the thixotropic aqueous mixture of the present invention include xanthan gum, gum arabic, pullulan, pectin, and carboxymethylcellulose. 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) smectite clay, b) lecithin, and c) xanthan gum or gum arabic. In some embodiments, the thixotropic aqueous mixture of the present invention may comprise a) smectite clay, b) lecithin, c) xanthan gum or gum arabic, d) an antioxidant, and optionally, sodium citrate. In any of these embodiments, the smectite clay may be, for example, montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite. For example, the thixotropic aqueous mixture of the present invention may comprise a) montmorillonite, b) lecithin, c) xanthan gum or gum arabic, and d) sodium citrate, or the thixotropic aqueous mixture of the present invention may comprise a) laponite, b) lecithin, c) xanthan gum or gum arabic, and d) sodium citrate.

[0043] Polysaccharides are present in any of the thixotropic aqueous mixtures of the present invention in an amount of 0.1 to 6.5% by weight, optionally 0.2 to 2.0% by weight, and optionally 0.2 to 1.5% by weight. For example, xanthan gum is assumed to be present in the mixture in an amount of 0.2 to 0.8% by weight, optionally 0.3 to 0.5% by weight. 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) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) glycerophospholipid in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) polysaccharide in an amount of 0.1 to 6.5% by weight, for example 0.2 to 2.0% by weight, for example 0.2 to 1.5% by weight. For example, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) polysaccharide in an amount of 0.1 to 6.5% by weight, for example 0.2 to 2.0% by weight, for example about 0.2 to 1.5% by weight. For example, the thixotropic aqueous mixture of the present invention may contain a) 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight of smectite clay; b) 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight of lecithin; c) 0.1 to 6.5% by weight, for example 0.2 to 2.0% by weight, for example about 0.2 to 1.5% by weight of polysaccharide; and d) 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example 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 smectite clay, b) about 2% by weight of lecithin, c) 0.1 to 6.5% by weight, for example 0.2 to 2.0% by weight, for example 0.2 to 1.5% by weight of polysaccharide, and about 0.2 or 0.25% by weight of sodium citrate. In any of these embodiments, the smectite clay may be montmorillonite, laponite, or a combination of montmorillonite and laponite.

[0045] Therefore, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) glycerophospholipid in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) xanthan gum in an amount of 0.2 to 0.8% by weight, for example 0.3 to 0.5% by weight. For example, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) xanthan gum in an amount of 0.2 to 0.8% by weight, for example 0.3 to 0.5% by weight. For example, the thixotropic aqueous mixture of the present invention may contain a) 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight of smectite clay; b) 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight of lecithin; c) 0.2 to 0.8% by weight, for example 0.3 to 0.5% by weight of xanthan gum; and d) 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example 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 smectite 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 smectite clay may be montmorillonite, laponite, or a combination of montmorillonite and laponite.

[0046] Furthermore, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) glycerophospholipid in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) gum arabic in an amount of 0.2 to 4.0% by weight, for example 0.5 to 2.0% by weight. For example, the thixotropic aqueous mixture of the present invention comprises a) smectite clay in an amount of 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight; b) lecithin in an amount of 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight; and c) gum arabic in an amount of 0.2 to 4.0% by weight, for example 0.5 to 2.0% by weight. For example, the thixotropic aqueous mixture of the present invention may contain a) 0.5 to 6.5% by weight, for example 1.0 to 5.0% by weight, for example 1.0 to 1.5% by weight of smectite clay; b) 0.5 to 4.0% by weight, for example 1.5 to 3.5% by weight, for example 1.5 to 2.5% by weight, for example about 2% by weight of lecithin; c) 0.2 to 4.0% by weight, for example 0.5 to 2.0% by weight of gum arabic; and d) 0.05 to 0.5% by weight, for example 0.1 to 0.3% by weight, for example 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 smectite clay, b) about 2% by weight of lecithin, c) 0.5 to 2.0% by weight of gum arabic, and about 0.2% by weight of sodium citrate. In any of these embodiments, the smectite clay may be montmorillonite, laponite, or a combination of montmorillonite and laponite.

[0047] In some embodiments, the ratio of polysaccharide to smectite 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 smectite clay may be 1:2 to 1:5, for example 1:2.5 to 1:4 (w / w), or the ratio of gum arabic to smectite clay may 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 (e.g., 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, the ratio of xanthan gum to lecithin is assumed to be 1:1 to 1:10, for example 1:3 to 1:5 (w / w), for example about 1:5 (w / w), or the ratio of gum arabic to lecithin is assumed to be 3:1 to 1:3, for example 1.5:1 to 1:2.5, for example 1:1.5 to 1.2.5 (w / w) or 1:1.5 to 1.2.0 (w / w).

[0049] Food-grade smectite clay, glycerophospholipids (e.g., lecithin), PVOH, and / or polysaccharides (e.g., xanthan gum or gum arabic) are particularly suitable for use in the present 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. Smectite clay and other solids are dispersed in water to form a colloidal dispersion. Water may further act as a solvent for any water-soluble polymer in the mixture. In some embodiments, the thixotropic aqueous mixture contains water and a further solvent such as ethanol (optionally, a food-grade solvent). If a volatile solvent such as ethanol is present, it constitutes no more than 25% of the total solvent in the mixture. In some embodiments, the thixotropic aqueous mixture of the present invention is an aqueous colloidal dispersion containing 2% to 10% solids, optionally 3% to 6% solids, and optionally 3.5% to 5.5% solids. In the aqueous colloidal dispersion, the smectite is not dissolved in the solution and is dispersed so that individual clay platelets 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 dried solids.

[0051] Thixotropic aqueous mixtures are typically edible and therefore safe for human or animal consumption. In some embodiments, thixotropic aqueous mixtures do not negatively modify the agricultural product to which they are applied. For example, if an agricultural product is organic, the thixotropic aqueous mixture is also organic. As used herein, the term “organic” refers to components that, when applied to an agricultural product, do not alter the organic state of the agricultural product. These components thus meet the standards set for organically produced agricultural products, for example, the rules for “organic” labeling set by the U.S. Department of Agriculture (USDA) National Organic Program (NOP). In some embodiments, organic thixotropic aqueous mixtures do not contain inorganic components, and as used herein, the term “inorganic” refers to components that, when applied to an agricultural product, alter the organic state of the agricultural product.

[0052] The present invention also provides methods for producing thixotropic aqueous mixtures and mixtures produced by these methods. Methods for producing thixotropic aqueous mixtures generally include at least one mixing step carried out under high shear.

[0053] Accordingly, in a second aspect, the present invention provides a method for producing the thixotropic aqueous mixture of the present invention. This method comprises mixing water with at least one smectite clay and a glycerophospholipid (e.g., lecithin), and optionally one or more additional components as described herein. At least one mixing step is carried out under high shear. This forms the thixotropic aqueous mixture of the present invention.

[0054] In the method of the present invention, smectite clay and other solids are dispersed in water. Water, if present, can also act as a solvent for water-soluble polymers. In some embodiments, the method uses water and a further solvent (optionally a food-grade solvent), optionally a volatile solvent, such as ethanol. If a volatile solvent such as ethanol is present, it constitutes no more than 25% of the total solvent used in this method.

[0055] The present invention's method for producing a thixotropic aqueous mixture comprises at least one step carried out under high shear. Any method or step of method described herein involving high shear mixing may be carried out using any known high shear mixer such as a vane mixer, Cowles dissolver, or colloid mill. High shear mixing requires high RPM and horsepower equipment to ensure that the dispersion blades can reach a maximum speed between 2,500 and 5,000 feet / min. The high shear mixing process may take 1 to 2 hours. A high shear blender may be used to mix smaller batches of composition. The high shear method is advantageous because it achieves rapid dispersion of smectite clay in water and / or rapid mixing of the smectite clay with one or more other components of the mixture to form a thixotropic aqueous mixture that ensures uniform dispersion of smectite clay particles (platelets). When using standard mixing methods without high shear (such as tanks equipped with paddle mixers), mixing smectite clay and other components in water does not completely disperse the smectite clay to form a uniformly dispersed mixture. This is because the smectite clay plates are held together by many weak bonds, such as hydrogen bonds and ionic dipole interactions, which collectively create a large cohesive force. Standard mixing is not sufficient to overcome this cohesive energy. When using a method with high shear, the increased energy and substantial force imposed by the high shear are sufficient to break the forces holding the clay plates together. Therefore, the high-shear method for producing the thixotropic aqueous mixture of the present invention is highly efficient.

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

[0057] Alternatively, the smectite clay and glycerophospholipid (e.g., lecithin) may be added separately to water and mixed under high shear. In these embodiments, adding the components "separately" includes adding the components to water simultaneously or adding each component sequentially. Thus, in some embodiments, the method includes adding at least one smectite clay to water, followed by high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water, then adding a glycerophospholipid (e.g., lecithin) to the colloidal dispersion, and optionally, further high-shear mixing thereafter. In other embodiments, the method includes adding the smectite clay and glycerophospholipid (e.g., lecithin) to water and then mixing under high shear.

[0058] In some embodiments, the present invention's method for producing a thixotropic aqueous mixture comprises mixing a) at least one smectite clay, b) glycerophospholipid (e.g., lecithin), and c) an antioxidant (e.g., sodium citrate) with water to form a thixotropic aqueous mixture. In some embodiments, the method comprises mixing a) at least one smectite clay, b) lecithin, and c) sodium citrate with water to form a thixotropic aqueous mixture. At least one mixing step of the method is carried out under high shear.

[0059] It is assumed that smectite clay, glycerophospholipids (e.g., lecithin), and antioxidants (e.g., sodium citrate) are mixed together in powder form, and then this "premix" of smectite clay, glycerophospholipids, and antioxidants is combined with water (e.g., added to water) and mixed under high shear mixing conditions. Alternatively, it is assumed that smectite clay, glycerophospholipids (e.g., lecithin), and antioxidants (e.g., sodium citrate) are added separately to water and mixed under high shear. In these embodiments, adding the components "separately" includes adding the components to water simultaneously, adding other components sequentially to add two components simultaneously, or adding each component sequentially. Therefore, in some embodiments, the method involves adding smectite clay to water, followed by high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water, then adding a glycerophospholipid (e.g., lecithin) and an antioxidant (e.g., sodium citrate) to the colloidal dispersion, and optionally further high-shear mixing. In other embodiments, the method involves adding smectite clay and a glycerophospholipid (e.g., lecithin) to water, followed by mixing under high shear, then adding an antioxidant (e.g., sodium citrate) to the mixture, and optionally further high-shear mixing. In a further embodiment, the method includes adding smectite clay to water and subsequently high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water; then adding a glycerophospholipid (e.g., lecithin) to the aqueous colloidal dispersion and subsequently optionally further high-shear mixing; then adding an antioxidant (e.g., sodium citrate) to the mixture and subsequently optionally further high-shear mixing.

[0060] In some embodiments, the present invention's method for producing a thixotropic aqueous mixture comprises mixing a) at least one smectite clay, b) glycerophospholipid (e.g., lecithin), and c) a water-soluble polymer (e.g., PVOH or polysaccharide) with water to form a thixotropic aqueous mixture. In some embodiments, the method comprises mixing a) at least one smectite clay, b) lecithin, and c) PVOH or polysaccharide (e.g., xanthan gum or gum arabic) with water to form a thixotropic aqueous mixture. At least one mixing step of the method is carried out under high shear.

[0061] Smectite clay, glycerophospholipids (e.g., lecithin), and water-soluble polymers (e.g., PVOH or polysaccharides) may be mixed together in powder form, and then this “premix” of smectite clay, glycerophospholipids, and polymers is combined with water (e.g., added to water) and mixed under high-shear mixing conditions. Alternatively, smectite clay, glycerophospholipids (e.g., lecithin), and water-soluble polymers (e.g., PVOH or polysaccharides) may be added separately to water and mixed under high-shear conditions. In these embodiments, adding the components “separately” includes adding the components to water simultaneously, adding other components sequentially to add two components simultaneously, or adding each component sequentially. Therefore, in some embodiments, the method involves adding smectite clay to water, followed by high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water, then adding a glycerophospholipid (e.g., lecithin) and a water-soluble polymer (e.g., PVOH or polysaccharide) to the colloidal dispersion, followed by optionally further high-shear mixing. In other embodiments, the method involves adding smectite clay and a glycerophospholipid (e.g., lecithin) to water, followed by mixing under high shear, then adding a water-soluble polymer (e.g., PVOH or polysaccharide) to the mixture, followed by optionally further high-shear mixing. In a further embodiment, the method comprises adding smectite clay to water and subsequently high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water; then adding a glycerophospholipid (e.g., lecithin) to the aqueous colloidal dispersion and optionally further high-shear mixing; and then adding a water-soluble polymer (e.g., PVOH or polysaccharide) to the mixture and optionally further high-shear mixing.

[0062] In some embodiments, the present invention's method for producing a thixotropic aqueous mixture comprises mixing a) at least one smectite clay, b) glycerophospholipid (e.g., lecithin), c) a water-soluble polymer (e.g., PVOH or polysaccharide), and d) an antioxidant (e.g., sodium citrate) with water to form a thixotropic aqueous mixture. In some embodiments, the method comprises mixing a) at least one smectite clay, b) lecithin, c) PVOH or polysaccharide (e.g., 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 carried out under high shear.

[0063] Smectite clay, glycerophospholipids (e.g., lecithin), water-soluble polymers (e.g., PVOH or polysaccharides), and antioxidants (e.g., sodium citrate) may be mixed together in powder form, and then this smectite clay, glycerophospholipid, polymer, and antioxidant “premix” is to be combined with water (e.g., added to water) and mixed under high shear mixing conditions. Alternatively, the smectite clay, glycerophospholipids (e.g., lecithin), water-soluble polymers (e.g., PVOH or polysaccharides), and antioxidants (e.g., sodium citrate) may be added separately to water and mixed under high shear. In these embodiments, adding the components “separately” includes adding the components to water simultaneously, adding other components sequentially to add two components simultaneously, or adding each component sequentially. Therefore, in some embodiments, the method involves adding smectite clay to water, followed by high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water, then adding a glycerophospholipid (e.g., lecithin), a water-soluble polymer (e.g., PVOH or polysaccharide), and an antioxidant (e.g., sodium citrate) to the colloidal dispersion, followed by optional further high-shear mixing. In other embodiments, the method involves adding smectite clay and a glycerophospholipid (e.g., lecithin) to water, followed by mixing under high shear, then adding a water-soluble polymer (e.g., PVOH or polysaccharide) and an antioxidant (e.g., sodium citrate) to the mixture, followed by optional further high-shear mixing. In a further embodiment, the method includes adding smectite clay to water and subsequently high-shear mixing to form an aqueous colloidal dispersion of smectite clay in water; then adding a glycerophospholipid (e.g., lecithin) to the aqueous colloidal dispersion and optionally further high-shear mixing; then adding a water-soluble polymer (e.g., PVOH or polysaccharide) to the mixture and optionally further high-shear mixing; then adding an antioxidant (e.g., sodium citrate) to the mixture and optionally further high-shear mixing.

[0064] The descriptions and definitions provided herein in the context of the thixotropic aqueous mixture of the present invention also apply to the method of the present invention for producing the thixotropic aqueous mixture. In particular, the smectite clay and glycerophospholipid used in the method may be as described in the context of the thixotropic aqueous mixture of the present invention and may be used in the amounts and / or ratios described in the context of the thixotropic aqueous mixture of the present invention. In embodiments of the method using antioxidants and / or water-soluble polymers, these components may be as described in relation to the thixotropic aqueous mixture of the present invention and may be used in the amounts and / or ratios described in relation to the thixotropic aqueous mixture 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, a thixotropic aqueous mixture prepared by any of the methods of the present invention may contain smectite clay (e.g., montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite) and lecithin. In some embodiments, a thixotropic aqueous mixture prepared by any of the methods of the present invention contains smectite clay, lecithin, and sodium citrate. In some embodiments, a thixotropic aqueous mixture prepared by any of the methods of the present invention contains smectite clay, lecithin, PVOH, and sodium citrate. Or it contains smectite clay, lecithin, polysaccharide (e.g., xanthan gum or gum arabic), and sodium citrate. A thixotropic aqueous mixture prepared by any of the methods of the present invention may be edible and optionally organic. These terms have the meanings defined herein.

[0066] Any of the methods of the present invention for producing a thixotropic aqueous mixture may further include applying the thixotropic aqueous mixture to the surface of an agricultural product. Accordingly, the present invention provides a method comprising i) producing a 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 agricultural product to which it is applied. The coating provides the surface of the agricultural product with one or more beneficial barrier properties, as defined herein. The coating may protect the agricultural product from dehydration and / or oxidation, and / or the coating may slow the ripening of the agricultural product compared to an uncoated agricultural product. Thereafter, the coating may improve the shelf life of the agricultural product compared to the same agricultural product lacking the coating of the present invention.

[0067] In a third embodiment, the present invention provides a method comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product in order to achieve one or more beneficial properties. In some embodiments, the present invention provides a method comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product in order to improve one or more barrier properties (e.g., gas and / or moisture barrier properties) of the surface of an agricultural product so that one or more barrier properties of the surface are improved compared to one or more barrier properties of an uncoated agricultural product surface. In some embodiments, the present invention provides a method comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product in order to protect an agricultural product from dehydration and / or oxidation. In some embodiments, the present invention provides a method comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product in order to delay the ripening of the agricultural product so that the ripening of the agricultural product is delayed compared to the ripening of an uncoated agricultural product. In some embodiments, the present invention provides a method comprising applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product in order to extend the shelf life of the agricultural product so that the shelf life of the agricultural product is extended 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, the agricultural product is a fruit. In some embodiments, the agricultural product is a ripening fruit, such as a pome fruit or avocado. In some embodiments, the agricultural product is a pome fruit (e.g., apple or pear), a drupe fruit (including avocado and cherry), a citrus fruit (e.g., lemon or mandarin), or a tomato. The present invention is particularly applicable to pome fruits, more specifically apples, pears, and / or quince. In some embodiments, the agricultural product is a vegetable agricultural product. For example, a vegetable agricultural product may be a cucumber or a mushroom.

[0069] In all embodiments of the present 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 may be called the peel, outer layer, or fruit peel depending on the type of agricultural product. For example, in some embodiments, the present invention relates to thixotropic aqueous mixtures and methods for improving one or more barrier properties (e.g., gas and / or moisture barrier properties) of the peel of pomegranate fruits such as apples or pears compared to the same uncoated pomegranate fruits. In some embodiments, the thixotropic aqueous mixtures and methods of the present invention reduce the movement of gases, including oxygen and carbon dioxide, through the peel of pomegranate fruits, thereby reducing the respiration rate of pomegranate fruits and slowing the ripening effect of ethylene on pomegranate fruits. By reducing the movement of atmospheric oxygen through the peel of pomegranate fruits, the thixotropic aqueous mixtures and methods of the present invention can protect the fruit from oxidation. Furthermore, by reducing the loss of water-containing moisture through the peel of pomegranate fruits, the thixotropic aqueous mixtures of the present invention can protect the fruit from transpiration and / or dehydration. Any one or more of these barrier properties may contribute to improving the shelf life and / or the shelf life of pome fruits.

[0070] The thixotropic aqueous mixture used in the methods of the present invention may 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 smectite clay (e.g., montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite) and lecithin. In some embodiments, the thixotropic aqueous mixture used in the methods of the present invention comprises smectite clay, lecithin, and sodium citrate. In some embodiments, the thixotropic aqueous mixture used in the methods of the present invention comprises smectite clay, lecithin, PVOH, and sodium citrate, or comprises smectite clay, lecithin, polysaccharide (e.g., 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 methods of the present invention utilizing thixotropic aqueous mixtures. In particular, the smectite clay and glycerophospholipid components of the thixotropic aqueous mixture used in any of the methods of the present invention may be as described in the context of the thixotropic aqueous mixture of the present invention, and may be used in the amounts and / or ratios described in the context of the thixotropic aqueous mixture of the present invention. In a method using a thixotropic aqueous mixture comprising an antioxidant and / or a water-soluble polymer, these components may be as described in the context of the thixotropic aqueous mixture of the present invention, and may be used in the amounts and / or ratios described in the context of the thixotropic aqueous mixture of the present invention.

[0071] In some embodiments, the thixotropic aqueous mixture is applied to agricultural products before harvest, while in other embodiments, it is applied after harvest. The greatest effect on shelf life is observed when the thixotropic aqueous mixture is applied before harvest, but a substantial effect is also observed when the agricultural products are coated after storage.

[0072] In a method of the present invention comprising applying a thixotropic aqueous mixture to the surface of an agricultural product, it is assumed that the thixotropic aqueous mixture may be applied by any one or more means suitable for applying a thin, uniform coating of the mixture to the surface of the agricultural product. For example, the thixotropic aqueous mixture may be applied to the surface of an agricultural product by immersion 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, or 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, the thixotropic aqueous mixture may be applied to the surface of agricultural products using a dip tank, a spray bar or brush bed, or any combination thereof.

[0074] In some embodiments, the thixotropic aqueous mixture is applied using a dip tank. A dip tank is a device capable of holding 5,000 to 10,000 liters of the thixotropic aqueous mixture of the present invention and facilitates dipping of agricultural products to coat their surfaces. For example, agricultural products are dipped once in the thixotropic aqueous mixture for a dipping time of 2 to 5 minutes. Using a dip tank, the thixotropic aqueous mixture of the present invention can be applied to agricultural products at a rate of about 500 pounds of agricultural products per liter of mixture. After applying the mixture using a dip tank, the agricultural products may be placed on a drainage belt to remove excess mixture.

[0075] The thixotropic aqueous mixture is envisioned to be applied to the surface of agricultural products using a combination of a dip tank and a brush bed. The brush bed typically has 6 to 12 rotating brushes that act for both conveying and brushing the agricultural products. After the thixotropic aqueous mixture is applied to the surface of the agricultural products, these brushes uniformly and efficiently 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 a uniform coating of the thixotropic aqueous mixture on the agricultural products and avoids the use of excess mixture.

[0076] In some embodiments, the thixotropic aqueous mixture is applied using a spray bar, or optionally using a combination of a spray bar and a brush bed. The spray bar is a device comprising a pump and at least one nozzle for spraying the thixotropic aqueous mixture onto the crop. During the application phase, the high shear provided by the pump and spray nozzle of the spray bar reduces the viscosity of the thixotropic aqueous mixture, thereby reducing the flow resistance when the thixotropic aqueous mixture is applied to the surface of the crop. Using the spray bar, the thixotropic aqueous mixture can be applied to the crop at a spray rate ranging from at least 1,000 pounds of crop per liter of thixotropic aqueous mixture, for example, 1,000 to 7,000 pounds of crop per liter of mixture, or for example, 3,000 to 7,000 pounds of crop per liter of mixture. When the spray of the thixotropic aqueous mixture hits the surface of the crop (i.e., the thixotropic aqueous mixture comes into contact with the surface of the crop), the viscosity is restored, forming a fairly uniform coating on the crop. This advantageous feature observed during the application of the thixotropic aqueous mixture of the present invention is due to the non-Newtonian hydrodynamics of the thixotropic mixture. In some embodiments, the thixotropic aqueous mixture is sprayed onto the surface of agricultural products using a spray bar, and then a brush bed is used as described above to enhance the coverage of the coating.

[0077] After immersing the crops in a thixotropic aqueous mixture in a dip tank, spraying may be optionally performed in front of the brush beds. For example, after the crops have exited the dip tank and drainage belt, additional thixotropic aqueous mixture may be sprayed onto the crops using a spray bar positioned behind the drainage belt and in front of any brush beds.

[0078] Before applying the thixotropic mixture, the produce may be washed in a dunk tank. A dunk tank is typically a 10,000-liter tank used to introduce the produce into the pack line, wash it, and remove debris such as leaves and twigs. The use of a dunk tank is advantageous because it minimizes the damage that may be inflicted on the produce during these processes. The dunk tank and / or dip tank may contain fungicides such as paracidic acid.

[0079] The method may further include drying the thixotropic aqueous mixture after application to the surface of the agricultural product (e.g., by applying heat), but more typically the mixture is left to air dry on the surface of the agricultural product under ambient conditions.

[0080] The coatings formed when using the thixotropic aqueous mixture of the present invention are generally transparent. As used herein, the term “transparent” refers to a coating that allows light to pass through. Thus, a coating film on a surface may be undetectable to the human eye, except for any gloss that could distinguish the coated surface from the uncoated surface. Therefore, a transparent coating allows for a clear view of the surface of agricultural products through the coating. Those skilled in the art can determine whether a coating is transparent by sight or by using methods known in the art.

[0081] The present invention's method for coating agricultural product surfaces with the thixotropic aqueous mixture has been demonstrated to improve one or more barrier properties of agricultural product surfaces compared to agricultural product surfaces that are not coated with the thixotropic aqueous mixture of the present invention (i.e., “uncoated” surfaces / “uncoated agricultural products” which may have different (e.g., wax-based) coatings or may not have any kind of coating). For example, the present invention creates a barrier between the agricultural product surface and the external environment that reduces the movement of gases and / or moisture across the surface compared to an uncoated surface; that is, the method envisions applying a layer of the thixotropic aqueous mixture to the agricultural product surface that acts as a gas and / or moisture (e.g., water vapor) barrier. Therefore, by applying the thixotropic aqueous mixture of the present invention to agricultural product surfaces, the movement of gases including oxygen and carbon dioxide across the agricultural product surface can be reduced, thereby lowering the respiration rate of the agricultural product, slowing the effect of ethylene on the ripening of the agricultural product, and / or protecting the agricultural product from oxidation. Furthermore, by applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products, the loss of water-containing moisture passing through the surface of the agricultural products can be reduced, thereby protecting the agricultural products from dehydration. Any one or more of these barrier properties may contribute to improving the shelf life and / or shelf life of agricultural products.

[0082] In some embodiments, the thixotropic aqueous mixtures and methods of the present invention are for protecting agricultural products from dehydration. Dehydration of agricultural products is accelerated by drier environmental conditions and exposure to air / oxygen. For example, water is lost from agricultural products such as fruits (e.g., pome fruits) and vegetables during storage. The thixotropic aqueous mixtures and associated methods of the present invention are useful in reducing moisture loss from agricultural products by reducing the water vapor permeability across the surface of the agricultural product to which the thixotropic aqueous mixture is applied. As used herein, protecting agricultural products "from dehydration" means protecting them from moisture loss (such as water loss) through the surface of the agricultural product. In these embodiments, "protection" from dehydration also includes reducing or even preventing dehydration. A reduction in dehydration may be defined in comparison to the dehydration of the same agricultural product not coated with the thixotropic aqueous mixture of the present invention (i.e., the same agricultural product without the coating composition, or the same agricultural product coated with a conventional composition known in the art). Methods for observing and measuring dehydration of agricultural products are known in the art. For example, dehydration can be measured by weighing agricultural products at time intervals, and a decrease in weight compared to previous weight measurements corresponds to a decrease in moisture content.

[0083] In some embodiments, pome fruits coated in the thixotropic aqueous mixture of the present invention lose at least 25% less weight (e.g., at least 30% less weight, or at least 40% or 45% less weight) during 9 days of storage at ambient temperature compared to the same uncoated produce (control). When monitored for longer periods, in some embodiments, pome fruits lose at least 10% less weight (e.g., at least 20% less weight, or at least 25% less weight) during 24 days of storage at ambient temperature compared to the same uncoated produce (control). For example, it is demonstrated herein that pears coated with any of the eight different thixotropic aqueous mixtures of the present invention lost an average of 29% to 49% less weight during 9 days of storage at ambient temperature compared to uncoated pears (i.e., had an average of 29% to 49% improved water retention). Furthermore, it is demonstrated herein that apples coated with any of the 13 different thixotropic aqueous mixtures of the present invention lost an average of 11% to 27% less weight during 24 days of storage at ambient temperature compared to uncoated apples (i.e., they had an average of 11% to 27% improved water retention). Thus, the thixotropic aqueous mixtures and methods of the present invention provide substantial protection against dehydration of pome fruits such as apples or pears.

[0084] In some embodiments, citrus fruits coated in the thixotropic aqueous mixture of the present invention lose at least 10% less weight (e.g., at least 20% less weight, or at least 25% less weight) during 3 days of storage at ambient temperature compared to the same uncoated produce (control). When monitored for longer periods, in some embodiments, citrus fruits lose at least 5% less weight (e.g., at least 10% less weight, or at least 15% less weight) during 7 days of storage at ambient temperature compared to the same uncoated produce (control). For example, it is demonstrated herein that lemons coated with various different thixotropic aqueous mixtures of the present invention lost an average of 24%–28% less weight during 3 days of storage at ambient temperature (i.e., had an average 24–28% improved water retention rate) and lost an average of 9%–16% less weight during 7 days of storage at ambient temperature (i.e., had an average 9–16% improved water retention rate) compared to uncoated lemons. Furthermore, it is demonstrated herein that mandarins coated with various different thixotropic aqueous mixtures of the present invention lost an average of 14%–22% less weight during 3 days of storage at ambient temperature (i.e., had an average improved water retention rate of 14–22%) and an average of 14%–18% less weight during 7 days of storage at ambient temperature (i.e., had an average improved water retention rate of 14–18%) compared to uncoated mandarins. Thus, the thixotropic aqueous mixtures and methods of the present invention provide substantial protection against dehydration of citrus fruits such as lemons or mandarins.

[0085] In some embodiments, the thixotropic aqueous mixtures and methods of the present invention are for protecting agricultural products from oxidation. Oxidation of agricultural products such as fruits (e.g., pome fruits) and vegetables causes browning and softening of the agricultural products. The thixotropic aqueous mixtures and related methods of the present invention are useful for protecting agricultural products from oxidation by reducing the oxygen permeability across the surface of the agricultural product to which the thixotropic aqueous mixture is applied. As used herein, protecting an agricultural product "from oxidation" means protecting the agricultural product or its surface from oxidation. In these embodiments, "protection" from oxidation also includes the reduction or even prevention of oxidation. Reduction of oxidation can be defined in comparison to the oxidation of the same agricultural product not coated with the thixotropic aqueous mixture of the present invention (i.e., the same agricultural product without the 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 known in the art. For example, the oxidation of agricultural products (e.g., browning and / or softening of agricultural products such as fruits, especially pome fruits) is typically observed and measured visually.

[0086] In some embodiments, the thixotropic aqueous mixtures and methods of the present invention are for delaying the ripening of agricultural products. Methods for observing and measuring when agricultural products are ripened and overripe are known in the art. For example, ripening of fruits and vegetables can be observed by sight or touch. In pears, the transition of color from green to yellow (observable visually) is an indicator of overripeness. Ripening can also be determined by measuring the resistance of the agricultural product to pressure (i.e., by determining its hardness). It is assumed that the time it takes for agricultural products coated with the thixotropic aqueous mixture of the present invention to reach ripening can be delayed by at least 10%, 20%, or 30% compared to uncoated control agricultural products. For example, as herein it is demonstrated, the thixotropic aqueous mixture of the present invention delays the time it takes for pears to ripen by about 30% compared to a control composition lacking lecithin and having a higher solids content. Pears coated with the thixotropic aqueous mixture of the present invention retained their attractive green color and showed fewer signs of skin damage after 7 days of storage compared to an uncoated control.

[0087] The shelf life of fresh produce can be defined as the length of time that the produce can be stored without becoming unsuitable for use, consumption, or sale. During the shelf life of produce, a specified percentage of the produce remains of acceptable quality under expected (or specified) conditions. Dehydration and / or oxidation of produce can reduce its shelf life. Therefore, protecting produce from dehydration and / or oxidation is useful to maintain or improve the expected shelf life of produce. “Improvement” in shelf life may be an extension of the time that produce can be stored without becoming unsuitable for use, consumption, or sale. Improvement in shelf life is achieved compared to the shelf life of the same produce not coated with the thixotropic aqueous mixture of the present invention (i.e., the same produce without the coating composition, or the same produce coated with a conventional composition known in the art). The extension of the shelf life of produce may be measured in days or as a percentage increase in shelf life compared to a control produce. For example, this specification demonstrates that the shelf life of pome fruits (e.g., pears) coated with the thixotropic aqueous mixture of the present invention can be extended by at least 4, 6, or 8 days compared to uncoated control produce.

[0088] In a fourth embodiment, 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 mixtures of the present invention to improve one or more barrier properties (e.g., gas and / or moisture barrier properties) of the surface of an agricultural product compared to one or more barrier properties of an uncoated agricultural product. In some embodiments, the present invention provides the use of the thixotropic aqueous mixtures of the present invention to protect agricultural products from dehydration and / or oxidation. In some embodiments, the present invention provides the use of the thixotropic aqueous mixtures of the present invention to delay the ripening of agricultural products. In some embodiments, the present invention provides the use of the thixotropic aqueous mixtures of the present invention to extend the shelf life of agricultural products. Protecting agricultural products from dehydration and / or oxidation, and methods for determining and measuring dehydration and / or oxidation, are defined herein. Similarly, “ripening” and “shelf life,” and methods for determining ripening and shelf life, are defined herein. The term “agricultural product” is also defined herein. In any of these uses of the present invention, the thixotropic aqueous mixture may be any of the thixotropic aqueous mixtures of the present invention described herein.

[0089] The thixotropic aqueous mixture for use in the present invention may be any of the thixotropic aqueous mixtures of the present invention described herein. In some embodiments, the thixotropic aqueous mixture used in the present invention comprises at least one smectite clay (e.g., montmorillonite, laponite, bentonite, or a combination of montmorillonite and laponite) and lecithin. In some embodiments, the thixotropic aqueous mixture used in the present invention comprises smectite clay, lecithin, and sodium citrate. In some embodiments, the thixotropic aqueous mixture used in the present invention comprises smectite clay, lecithin, PVOH, and sodium citrate, or comprises smectite clay, lecithin, polysaccharide (e.g., 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 smectite clay and glycerophospholipid components of the thixotropic aqueous mixture used in the present invention may be as described in the context of the thixotropic aqueous mixture of the present invention, and may be used in the amounts and / or ratios described in the context of the thixotropic aqueous mixture of the present invention. In any use of the thixotropic aqueous mixture comprising antioxidants and / or water-soluble polymers, these components may be as described in relation to the thixotropic aqueous mixture of the present invention, and may be used in the amounts and / or ratios described in relation to the thixotropic aqueous mixture of the present invention.

[0090] Further compositions and methods of the present invention The present invention also provides a thixotropic aqueous mixture comprising a) smectite clay, b) xanthan gum, and c) an antioxidant. This mixture is intended to protect agricultural products from dehydration and / or oxidation (it is suitable and effective for protection), and / or to delay the ripening of agricultural products, and / or to extend the shelf life of agricultural products.

[0091] In this embodiment of the present invention, any one or more smectite clays can be used. In some embodiments, the smectite clay is montmorillonite, or montmorillonite and hectorite. The smectite clay is assumed to be present in the thixotropic aqueous mixture in an amount of, for example, 0.5 to 4% by weight, optionally 1.0 to 4% by weight, or optionally 1.0 to 3.5% by weight. In some embodiments, the thixotropic aqueous mixture contains montmorillonite in an amount of 0.5 to 2.5% by weight, for example 1.0 to 2.0% by weight, or for example 1.0 to 1.5% by weight. In some embodiments, the thixotropic aqueous mixture further contains hectorite in an amount of 1.0 to 2.5% by weight, for example 1.5 to 2.0% by weight. Therefore, in some embodiments, the thixotropic aqueous mixture comprises a) montmorillonite, or montmorillonite and hectorite in an amount of 0.5 to 4% by weight, for example 1.0 to 4% by weight, for example 1.0 to 3.5% by weight, b) xanthan gum, and c) an antioxidant.

[0092] Xanthan gum is assumed to be present in the thixotropic aqueous mixture in an amount of 0.2–5.5% by weight, optionally 0.2–0.5% by weight, or 4.5–5.5% by weight. Therefore, in some embodiments, the thixotropic aqueous mixture comprises a) smectite clay, b) xanthan gum in an amount of 0.2–5.5% by weight, for example 0.2–0.5% by weight, or 4.5–5.5% by weight, and c) an antioxidant.

[0093] Accordingly, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising a) smectite clay in an amount of 0.5 to 4% by weight, for example 1.0 to 4% by weight, for example 1.0 to 3.5% by weight; b) xanthan gum in an amount of 0.2 to 5.5% by weight, for example 0.2 to 0.5% by weight, or 4.5 to 5.5% by weight; and c) an antioxidant. For example, the thixotropic aqueous mixture may comprise a) montmorillonite, or montmorillonite and hectorite in an amount of 0.5 to 4% by weight, for example 1.0 to 4% by weight, for example 1.0 to 3.5% by weight; b) xanthan gum in an amount of 0.2 to 5.5% by weight, for example 0.2 to 0.5% by weight, or 4.5 to 5.5% by weight; and c) an antioxidant.

[0094] In some embodiments, the ratio of at least one smectite clay to xanthan gum is 10:1 to 1:3, for example 8:1 to 1:4, for example about 4:1.

[0095] The antioxidant may be sodium citrate. Therefore, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising a) smectite clay, b) xanthan gum, and c) sodium citrate. For example, the thixotropic aqueous mixture may comprise a) montmorillonite, or montmorillonite and hectorite, b) xanthan gum, and c) sodium citrate. The antioxidant (e.g., sodium citrate) is assumed to be present in the mixture in an amount of, for example, 0.1 to 0.3% by weight, optionally about 0.2% by weight.

[0096] Accordingly, in some embodiments, the present invention provides a thixotropic aqueous mixture comprising: a) 0.5 to 4% by weight, for example 1.0 to 4% by weight, for example 1.0 to 3.5% by weight of smectite clay; b) 0.2 to 5.5% by weight, for example 0.2 to 0.5% by weight, or 4.5 to 5.5% by weight of xanthan gum; and c) 0.1 to 0.3% by weight, optionally about 0.2% by weight of an antioxidant (e.g., sodium citrate). For example, the thixotropic aqueous mixture may comprise: a) 0.5 to 4% by weight, for example 1.0 to 4% by weight, for example 1.0 to 3.5% by weight of smectite clay; b) 0.2 to 5.5% by weight, for example 0.2 to 0.5% by weight, or 4.5 to 5.5% by weight of xanthan gum; and c) 0.1 to 0.3% by weight, optionally about 0.2% by weight of sodium citrate. For example, a thixotropic aqueous mixture may contain a) 0.5 to 4% by weight, e.g., 1.0 to 4% by weight, e.g., 1.0 to 3.5% by weight of montmorillonite, or montmorillonite and hectorite; b) 0.2 to 5.5% by weight, e.g., 0.2 to 0.5% by weight, or 4.5 to 5.5% by weight of xanthan gum; and c) 0.1 to 0.3% by weight, optionally about 0.2% by weight of sodium citrate.

[0097] The total solids content of the thixotropic aqueous mixture is assumed to be 1-7%, optionally 3.5-7%, for example, about 4% solids.

[0098] A method for producing a thixotropic aqueous mixture is also provided, comprising mixing at least one smectite clay, xanthan gum, and an antioxidant with water under high shear to form a thixotropic aqueous mixture. The at least one smectite clay, xanthan gum, and antioxidant are as defined above in the context of the thixotropic aqueous mixture of the present invention. Thus, in some embodiments, the at least one smectite clay is montmorillonite, or montmorillonite and hectorite, and / or the antioxidant is sodium citrate.

[0099] In some embodiments, at least one smectite clay, xanthan gum, and / or sodium citrate are combined in powder form, and the combined powder is then mixed with water under high shear. Alternatively, at least one smectite clay, xanthan gum, and sodium citrate are added separately (simultaneously or sequentially) to the water during high-shear mixing. The high-shear mixing process and suitable apparatus are as defined herein.

[0100] A thixotropic aqueous mixture prepared by the method of the present invention is also provided. In some embodiments, the high-shear method for producing the thixotropic aqueous mixture of the present invention further includes applying the thixotropic aqueous mixture to the surface of an agricultural product.

[0101] A method for protecting agricultural products from dehydration and / or oxidation is also provided, comprising applying the thixotropic aqueous mixture of the present invention to the surface of the agricultural products. 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 products, thereby delaying ripening compared to ripening of agricultural products to which the mixture is not 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 products, thereby extending the shelf life compared to ripening of agricultural products to which the mixture is not applied. The present invention also provides corresponding uses of the thixotropic aqueous mixture of the present invention. Protecting agricultural products from dehydration and / or oxidation, delaying the ripening of agricultural products, and extending the shelf life of agricultural products, as well as methods for measuring them, are as defined herein.

[0102] In any method of the present invention, which includes applying the thixotropic aqueous mixture of the present invention to the surface of an agricultural product, the agricultural product and the surface of the agricultural product are as defined herein. For example, the agricultural product is a fruit, and optionally a pome fruit.

[0103] In any method of the present invention, which includes applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products, the mixture may be applied using a dip tank, a spray bar, or a brush bed, or any combination thereof, optionally using a combination of a spray bar and a brush bed, or using a combination of a dip tank and a brush bed. For example, in some embodiments, the thixotropic aqueous mixture is applied using a spray bar at a spray rate ranging from 1,000 to 10,000 pounds of agricultural products per liter of the thixotropic aqueous mixture, optionally ranging from 5,000 to 8,000 pounds of agricultural products per liter of the thixotropic aqueous mixture, and optionally about 7,000 pounds of agricultural products per liter of the thixotropic aqueous mixture.

[0104] Further aspects of the present invention Unexpectedly, it was discovered that a mixture of certain water-soluble polymers, smectite clay, and glycerophospholipids, which form a highly thixotropic fluid in water when coated on agricultural products, increases shelf life and ready-eat window far more effectively than previous self-assembling coatings. Furthermore, unexpectedly, it was discovered that a mixture of certain water-soluble polymers, smectite clay, and glycerophospholipids and / or polysaccharides, which form a highly thixotropic fluid in water when coated on agricultural products, increases shelf life and ready-eat window. The thixotropic mixture of the present invention forms a very thin coating on agricultural products such as fruits and vegetables, extending shelf life and ready-eat window at much lower concentrations and doses than prior art. The new formulation has a much lower weight percentage of solids and therefore dries to a very thin coating that does not alter the appearance or texture of the fruit.

[0105] In one embodiment of the present invention, the mixture comprises at least one smectite clay, a water-soluble polymer, and a glycerophospholipid. For example, the mixture is envisioned to be an organic thixotropic aqueous mixture for increasing the shelf life and shelf life of agricultural products, comprising at least one smectite clay, a water-soluble polymer, and a glycerophospholipid.

[0106] At least one smectite clay component may include, but is not limited to, sodium montmorillonite, hectorite, or laponite, or mixtures thereof, e.g., sodium montmorillonite, sodium hectorite, or laponite, and mixtures thereof. Possible 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. The glycerophospholipid may include, but is not limited to, lecithin from various sources such as soy, sunflower, and egg. One preferred embodiment of the composition is sodium montmorillonite, food-grade polyvinyl alcohol (PVOH), and sunflower lecithin.

[0107] In one embodiment of the present invention, the coating composition contains at least one smectite clay in an amount of 0.5 to 4.5% by weight of the total composition on a volume basis. In another embodiment of the coating composition of the present invention, the composition contains a water-soluble polymer in an amount of 0.5 to 4.5% by weight of the total composition on a volume basis. In yet another embodiment of the coating composition of the present invention, the composition contains lecithin in an amount of 0.5 to 2.5% by weight of the total composition. Various ratios of at least one smectite clay to water-soluble polymer are assumed herein. In one embodiment, the ratio of at least one smectite clay to water-soluble polymer in the composition is 1:4 to 4:1. In another embodiment, the ratio of at least one smectite clay to water-soluble polymer in the composition is 1:1. In yet another embodiment, the aqueous dispersion of the composition has a solids content of 1 to 7%, for example, 1 to 6%.

[0108] This composition does not contain any components that alter the organic state of the fruit, nor does it require any additional components to achieve the desired results. Therefore, in some embodiments, the compositions described herein are novel edible and organic compositions for increasing shelf life and shelf life.

[0109] The present invention also provides a method for producing a thixotropic mixture and applying the mixture to agricultural products. For example, the present invention provides a method for producing a thixotropic mixture comprising at least one smectite clay, a glycerophospholipid, and a water-soluble polymer, and applying the mixture to fruit. At least one smectite clay, a water-soluble polymer, and a glycerophospholipid are added to water in a high-shear mixture and then applied to agricultural products via a tank, spray bar, or brush bed or a combination thereof. For example, at least one smectite clay, a water-soluble polymer, and food-grade lecithin are added to water in a high-shear mixture and then applied to agricultural products via a tank, spray bar, or brush bed or a combination thereof. This method of coating agricultural products with a composition of at least one smectite clay, a water-soluble polymer, and a glycerophospholipid (e.g., lecithin) increases shelf life and the period during which the product is at its best for consumption.

[0110] The present invention further provides a method for producing a thixotropic mixture comprising at least one smectite clay, a glycerophospholipid, a water-soluble polymer and / or a polysaccharide, and for applying the mixture to fruit. The present invention further provides a method for applying a thixotropic mixture comprising a water-soluble polymer, a smectite clay, a glycerophospholipid and / or a polysaccharide, to form a very highly oriented thin coating on fruit and vegetables, thereby extending shelf life and freshness with improved potency and at low doses. In one embodiment of the present invention, the components of the composition are pre-mixed in powder form, and the mixture is then added to water in a high-shear mix. In another embodiment of the present invention, the components of the composition are added separately to water in a high-shear mix.

[0111] The compositions of the present invention can be applied via tanks, spray bars, brush beds, or other methods to completely coat agricultural products with the thixotropic mixture. Therefore, a method for applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products is provided, wherein the composition is applied in a dip tank, a spray bar, or a brush bed, or any combination thereof. A preferred method of applying the coating of agricultural products in the disclosed composition is a combination of a spray bar and a brush bed to enhance the coverage of the coating. By applying the composition to agricultural products using a combination of a spray bar and a brush bed, the effectiveness can be significantly improved and the thickness of the coating can be minimized. Therefore, a method for applying the thixotropic aqueous mixture of the present invention to the surface of agricultural products to increase shelf life and shelf life is provided, wherein the composition is applied in a combination of a spray bar and a brush bed. Furthermore, a method for coating agricultural products with an organic thixotropic aqueous mixture, including a combination of a spray bar and a brush bed, is provided to increase shelf life and shelf life. In one embodiment of the present invention, fruits (e.g., pome fruits) are sprayed after the dip tank and before the brush bed. In some embodiments, the spray rate ranges from 1,000 pounds / liter to 7,000 pounds / liter of treated fruit. During the application phase, the shear force provided by the pump and spray nozzle reduces the viscosity of the fluid and decreases resistance to flow. When the spray hits the fruit surface, the viscosity is restored, forming a fairly uniform coating on the fruit. While the fruit is thus coated, the shear force applied by the brush further reduces the viscosity of the coating and orients the plate-like particles of nanoclay parallel to the fruit surface. This action assists in the formation of a highly oriented, self-organizing barrier coating with very high effectiveness.

[0112] The method of applying the coating composition to the fruit can be done either before or after harvest. The greatest effect is seen when the coating is applied before harvest, but if the fruit is coated after storage, a substantial effect is also seen on the storage life and the period during which it is at its best for consumption.

[0113] This invention utilizes the thixotropic properties of a self-assembling coating and the large aspect ratio of the nanoclay contained therein.

[0114] As used in the claims and specification herein, the terms “comprising,” “including,” and “having” shall be considered to indicate an open group that may include other elements not specified. The terms “a,” “an,” and the singular form of the word should be interpreted as including the plural form of the same word, and such terms mean that one or more things are offered. The terms “one” or “single” may be used to indicate that one and only one thing is intended. Similarly, when a specific number of things is intended, other specific integer values ​​such as “2” may be used. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that the item, condition, or process mentioned is an optional (not essential) feature of the invention.

[0115] The present invention is described with reference to various specific preferred embodiments and techniques. However, it should be understood that many modifications and alterations are possible while remaining within the spirit and scope of the invention. It will be apparent to those skilled in the art that methods, devices, device elements, materials, procedures, and techniques other than those specifically described herein can be applied to the implementation of the invention as broadly disclosed herein without relying on excessive experimentation. All functional equivalents known in the art of the methods, devices, device elements, materials, procedures, and techniques described herein are intended to be encompassed by the invention. Whenever a scope is disclosed, all sub-scopes and individual values ​​are intended to be encompassed. The present invention is not limited by the disclosed embodiments, but includes those shown in the drawings or illustrated herein, which are given as examples rather than limitations.

[0116] Although the present invention has been described in relation to a limited number of embodiments, those skilled in the art who are interested in this disclosure will understand that other embodiments can be devised that do not depart from the scope of the invention disclosed herein. Accordingly, the scope of the invention should be limited only by the appended claims.

[0117] All references throughout this application, such as patent documents, patent application publications, and non-patent documents or other source materials including issued or granted patents or equivalents, are incorporated herein by reference in whole, as if they were incorporated individually, provided that each reference does not contradict, at least partially, the disclosures of this application (for example, partially inconsistent references are incorporated by reference except for the partially inconsistent portion of the reference). [Examples]

[0118] Example 1: Thixotropic composition for extending the shelf life of D'Anjou pears A laboratory-scale test was conducted comparing a control self-assembling composition 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% laponite, 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, consisting of 0.576% laponite, 0.72% montmorillonite, 2.0% lecithin (derived from sunflower), 2.02% PVOH, and 0.252% sodium citrate. The total solids content was 5.5% by weight. Using the two formulations, Danjou pears were coated with the same amount of spray using a paint spray gun. The pears were then monitored for the transition from green to yellow. This color change is an indicator of overripeness. The control coating group 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 group, achieved using a formulation with 26% less solids content.

[0119] Example 2: Extending the shelf life of Bartlett pears by applying a thixotropic composition. A thixotropic composition containing montmorillonite, laponite, polyvinyl alcohol, and lecithin was applied to pears in two ways. The first method was by dipping in a tank, and the second was by using a combination of a spray bar and a brush bed. In the tests, the amount of coated fruit per liter was determined, and the amount of shelf life extension was determined using color change and pressure measurements. The pears used in the tests were Bartlett variety. For fruit coated in a dipping tank, the dose rate was determined to be 500 pounds of fruit per liter. Shelf life extension was 6 days longer than that of uncoated control pears. For pears coated using the spray bar and brush bed combination, the optimal dose rate was 7000 pounds / liter. Shelf life extension was 8 days longer than that of the uncoated control.

[0120] Example 3: Extending the shelf life of Argentine Packham Triumph pears In this example, common Argentine Paccam Triumph pears were coated by immersion in a 4.5% aqueous dispersion of thixotropy containing 0.945% bentonite, 1.48% polyvinyl alcohol, 1.89% lecithin, and 0.18% sodium citrate. The pears were stored at room temperature for 7 days. The coated fruits showed delayed color changes associated with ripening. Figure 1 shows that the coated pears retained a more attractive green color and showed fewer signs of damage to the skin surface compared to the uncoated control.

[0121] Example 4: Thixotropic coating to prevent dehydration of apples Tests were conducted to measure the effect of compositional variations of the thixotropic mixtures of the present invention on improving the shelf life of coated organic glass apples. In these tests, organic glass apples were coated with 13 different thixotropic aqueous mixtures containing varying proportions of montmorillonite (MMT), hectorite, lecithin, xanthan gum, and citrate. These mixtures were applied manually to simulate high-shear spray and brush bed conditions. The compositions of mixtures S1 to S13 are detailed in Table 1. [Table 1]

[0122] After 24 days, the apples were weighed to assess fruit dehydration contributing to spoilage. The average weight of each apple sample is summarized in Table 2 and Figure 2. Apples coated with one of the 13 mixtures had an average water retention rate of 11% to 27% compared to the uncoated control. Samples S7 and S11 had the most improved % water retention rates. [Table 2]

[0123] Example 5: Thixotropic coating to prevent dehydration in Bartlett pears A study was conducted to measure the effect of compositional variations of the thixotropic mixtures of the present invention on improving the shelf life of coated Bartlett pears. In this study, Bartlett pears were coated using eight different thixotropic mixtures containing varying proportions of montmorillonite (MMT), lecithin, gum arabic, and citrate. These mixtures were applied manually to simulate high-shear spray and brush-bed application methods. The compositions of mixtures S14–23 are detailed in Table 3. [Table 3]

[0124] At 4, 7, and 9 days, the pears were weighed to assess fruit dehydration contributing to spoilage. The average weight of each Bartlett pear sample is summarized in Table 4 and Figure 3. Pears coated with one of the eight mixtures had an average water retention rate of 29%–49% compared to the uncoated control after 9 days. Samples S21 and S22 had the most improved % water retention rate compared to the control. [Table 4]

[0125] Example 6: Thixotropic coating to prevent lemon dehydration A study was 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 study, lemons were coated using four different thixotropic mixtures containing varying proportions of montmorillonite (MMT), lecithin, citrate, and either xanthan gum or gum arabic. The compositions of mixtures S2 and S24-S26 are detailed in Table 5. [Table 5]

[0126] After 3, 5, and 7 days, the lemons were weighed to assess dehydration of the fruit that contributes 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 had an average water retention rate of 24%–27.5% compared to the uncoated control after 3 days, and an average water retention rate of 9%–13% compared to the uncoated control after 7 days. Sample S2 had the most improved percentage water retention rate. [Table 6]

[0127] Lemons coated with a thixotropic composition containing montmorillonite, optionally laponite (LAP), PVOH, lecithin, and citrate were also tested, and compositions S27 and S28 were formulated as detailed in Table 7. [Table 7]

[0128] Lemons were weighed after 3, 5, and 7 days to assess fruit dehydration. The average weight of each lemon sample is summarized in Table 8 and Figure 5. Lemons coated with either of the two mixtures had an average water retention rate of 26%–27.5% compared to the uncoated control after 3 days, and an average water retention rate of 11%–16% compared to the uncoated control after 7 days. Sample S27 had the most improved percentage water retention rate. [Table 8]

[0129] Example 7: Thixotropic coating to prevent dehydration in mandarins A study was 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 mandarins. In this study, mandarins were coated using four different thixotropic mixtures containing varying proportions of montmorillonite (MMT), lecithin, citrate, and xanthan gum or gum arabic. The compositions of mixtures S2, S24, S26, and S29 are detailed in Table 9. [Table 9]

[0130] Mandarins were weighed after 3, 5, and 7 days to assess fruit dehydration. The average weight of each mandarin sample is summarized in Table 10 and Figure 6. Mandarins coated with either of the two mixtures had an average water retention rate of 14%–19% compared to the uncoated control after 3 days, and an average water retention rate of 14%–18% compared to the uncoated control after 7 days. Sample S2 had the most improved % water retention rate. [Table 10]

[0131] Mandarins coated with thixotropic compositions S27 and S28, formulated as detailed in Table 7 for lemon coating, were also tested. After 3, 5, and 7 days, the mandarins were weighed to assess fruit dehydration. The average weight of each mandarin sample is summarized in Table 11 and Figure 7. Mandarins coated with either of the two mixtures showed an average water retention rate of 19%–22% compared to the uncoated control after 3 days, and an average water retention rate of 14–15% compared to the uncoated control after 7 days. The sample with the most improved percentage water retention rate was S27. [Table 11]

[0132] Example 8: Thixotropic coating to prevent dehydration in cherries In this study, cherries were coated using three different thixotropic mixtures containing varying proportions of montmorillonite (MMT), xanthan gum, lecithin, and citrate. The compositions of mixtures S30 and S31 are detailed in Table 12. [Table 12]

Claims

1. A thixotropic aqueous mixture for protecting agricultural products from dehydration and / or oxidation, a) Smectite clay and b) Glycerophospholipids and A thixotropic aqueous mixture containing the above.

2. The thixotropic aqueous mixture according to claim 1, wherein the smectite clay is montmorillonite, laponite, or bentonite, or montmorillonite and laponite.

3. The thixotropic aqueous mixture according to claim 1 or claim 2, wherein the glycerophospholipid is lecithin, and optionally the lecithin is soy lecithin, sunflower lecithin, or egg lecithin, or derived therefrom.

4. The thixotropic aqueous mixture according to any one of claims 1 to 3, wherein the smectite 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 to 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, and optionally 1.5 to 2.5% by weight.

6. The thixotropic aqueous mixture according to any one of claims 1 to 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, and optionally about 0.7:1 (w / w).

7. A thixotropic aqueous mixture according to any one of claims 1 to 6, further comprising an antioxidant, wherein optionally 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, and optionally in an amount of 0.1 to 0.3% by weight.

9. a) Smectite clay and b) Lecithin and, c) Sodium citrate and A thixotropic aqueous mixture according to claim 7 or claim 8, comprising:

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

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

12. a) Smectite clay and b) Lecithin and, c) PVOH and, d) Sodium citrate and A thixotropic aqueous mixture according to claim 11, comprising:

13. The thixotropic aqueous mixture according to claim 12, wherein the smectite clay is bentonite, laponite, or montmorillonite and laponite.

14. The thixotropic aqueous mixture according to any one of claims 11 to 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, or optionally about 2.0% by weight.

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

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

17. a) Smectite clay and b) Lecithin and, c) Xanthan gum or gum arabic, d) Sodium citrate and A thixotropic aqueous mixture according to claim 16, comprising:

18. The thixotropic aqueous mixture according to claim 17, wherein the smectite clay is montmorillonite or laponite.

19. The one or more polysaccharides are present in the mixture in an amount of 0.2 to 6.5% by weight. Optionally, xanthan gum may be present in the mixture in an amount of 0.2 to 0.6% by weight. Optionally, gum arabic is present in the mixture in an amount of 0.2 to 2.0% by weight, and optionally 0.5 to 2.0% by weight. A thixotropic aqueous mixture according to any one of claims 15 to 18.

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

21. A method for producing 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 at least one smectite clay is montmorillonite, laponite, bentonite, or montmorillonite and laponite, and / or Glycerophospholipids are lecithin. The method according to claim 21.

23. The at least one smectite 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 smectite clay and the glycerophospholipid are added separately to the water during high-shear mixing. The method according to claim 21 or claim 22.

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

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

26. A thixotropic mixture prepared by the method described in any one of claims 21 to 25.

27. It is a method, i) Producing a thixotropic aqueous mixture using the high-shear method described in any one of claims 21 to 25, ii) Applying the thixotropic aqueous mixture to the surface of agricultural products Methods that include...

28. A method for protecting agricultural products from dehydration and / or oxidation, comprising applying a thixotropic aqueous mixture according to any one of claims 1 to 20 or 26 to the surface of the agricultural products.

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

30. The thixotropic aqueous mixture is applied to the surface of agricultural products using a dip tank, spray bar, brush bed, or any combination thereof. Optionally, the thixotropic aqueous mixture may be applied using a combination of a spray bar and a brush bed, or a combination of a dip tank and a brush bed. The method according to any one of claims 27 to 29, wherein the thixotropic aqueous mixture is optionally applied using a spray bar at a spray rate of 1,000 to 10,000 pounds of agricultural product per liter of the thixotropic aqueous mixture, optionally in the range of 5,000 to 8,000 pounds of agricultural product per liter of the thixotropic aqueous mixture, and optionally at a spray rate of approximately 7,000 pounds of agricultural product per liter of the thixotropic aqueous mixture.

31. Use of the thixotropic aqueous mixture according to any one of claims 1 to 20 or 26 for protecting the agricultural product from dehydration and / or oxidation.

32. Use of a thixotropic aqueous mixture according to any one of claims 1 to 20 or 26 for delaying the ripening of agricultural products.

33. The method according to any one of claims 27 to 30, or the use according to claim 31 or 32, wherein the agricultural product is a fruit, optionally a pome fruit, or a citrus fruit.

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