A zinc-rich rapeseed oil and a method for its production

Abstract

The application discloses a kind of zinc-rich rapeseed oil and preparation method thereof, belong to food processing technical field, the organic zinc fortifier of the present application is dispersed into water, and after hydration at low temperature, organic zinc solution is obtained by adding stabilizer;Antioxidant and emulsifier are added to rapeseed oil to form rapeseed oil premix;Organic zinc aqueous solution is added dropwise to rapeseed oil premix, and homogeneous mixing is carried out by vacuum high-speed shearing, and zinc-rich rapeseed oil is obtained after standing.The preparation method of the zinc-rich rapeseed oil of the present application provides a new way for the nutritional fortification of zinc in lipid-soluble system.The method of the present application effectively improves the comprehensive utilization rate of raw materials.The zinc-rich rapeseed oil of the present application is prepared by one-step method, and the process is simple, which lays a foundation for industrialized expansion production.The zinc content of the zinc-rich rapeseed oil prepared by the present application is controllable, and the zinc content of the zinc-rich rapeseed oil is stable in a long storage period.

Description

Technical Field

[0001] This invention belongs to the field of food processing, specifically relating to a zinc-rich rapeseed oil and its preparation method. Background Technology

[0002] Rapeseed oil, one of the world's three major oils, is also known as rapeseed oil, coriander oil, sesame oil, and canola oil. Rapeseed oil itself has a very high erucic acid content, and it is classified into ordinary rapeseed oil and low-erucic acid rapeseed oil based on the stage of rapeseed oil production. Due to different extraction methods, rapeseed oil can be divided into pressed rapeseed oil and solvent-extracted rapeseed oil. Whether or not genetically modified technology is used in the cultivation of rapeseed, the resulting rapeseed oil can be divided into genetically modified rapeseed oil and non-genetically modified rapeseed oil. Hot-pressed rapeseed oil is mainly obtained by roasting or heat-treating the seeds before pressing. Some hot-pressed rapeseed oils are known as "fragrant rapeseed oil" in my country and are very popular with consumers, such as 7D rapeseed oil. The human body has a high absorption rate of rapeseed oil, reaching up to 99%, which can promote digestion. Rapeseed oil has certain effects such as softening blood vessels, delaying aging, reducing inflammation, improving skin, and lowering cholesterol. However, rapeseed oil itself is not rich in zinc and cannot provide the same zinc supplementation through a daily diet.

[0003] Zinc, known as the "element of life," plays diverse physiological roles in the body, widely participating in the metabolism of carbohydrates, proteins, lipids, DNA, and RNA. Zinc is a component of over 200 metalloenzymes, such as DNA polymerase, RNA polymerase, and alcohol dehydrogenase, and is also an activator of over 300 enzymes, playing a crucial role in vital physiological processes such as growth and development, reproduction and heredity, immunity, and endocrine function. Zinc deficiency can impair health. In children, zinc deficiency can delay growth and development, resulting in short stature and low weight, as well as loss of appetite, weakened immunity, oral ulcers, and mood swings. In adults, zinc deficiency can damage gonadal function, lead to neurological dysfunction, and immune system disorders. In pregnant women, zinc deficiency can cause cravings for sour foods, worsened vomiting, premature birth, and fetal malformations. However, excessive zinc intake can also cause discomfort such as abdominal pain, vomiting, diarrhea, gastrointestinal bleeding, loss of appetite, fatigue, and drowsiness. Therefore, appropriate zinc supplementation is beneficial for the normal functioning of the human body.

[0004] CN107114492A discloses a method for preparing zinc-enriched olive oil. Although inorganic zinc is converted into organic zinc through olive pomace fermentation and then mixed with crude olive oil for extraction, the organic zinc has extremely low solubility in the oil phase and is difficult to migrate from the aqueous phase into the olive oil system.

[0005] Therefore, providing a method for directly preparing zinc-rich rapeseed oil by one-step homogeneous dispersion of organic zinc aqueous solution is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, and considering the extremely low solubility of zinc supplements in rapeseed oil, making it impossible to achieve zinc enrichment in rapeseed oil using conventional methods, this invention dissolves zinc supplements such as zinc glycinate in water. Then, a hydrophobic emulsifier such as polyglycerol ricinoleate and a polysaccharide stabilizer are used to form an interfacial film at the interface to stabilize the oil-water system. Under strict moisture control, the organic zinc is emulsified and solubilized in rapeseed oil, thereby achieving the goal of increasing zinc fortification in rapeseed oil.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing zinc-enriched rapeseed oil, characterized by comprising the following steps:

[0009] (1) Preparation of organic zinc solution: Weigh the organic zinc solid, add water to prepare an organic zinc aqueous solution, and let it stand to confirm that no solid precipitates; take the prepared organic zinc aqueous solution, add the stabilizer, stir at 40-70℃ to dissolve completely, cool and hydrate at 4℃ for 4-12h, remove the solid precipitate after hydration to obtain the organic zinc solution for later use.

[0010] (2) Preparation of rapeseed oil premix: Add antioxidant to rapeseed oil and dissolve it completely at 50-80℃. Add emulsifier and stir at room temperature for 5-15 minutes to mix evenly to obtain rapeseed oil premix for later use.

[0011] (3) Two-phase mixing and homogenization: Add the organic zinc aqueous solution dropwise to the rapeseed oil premix, stir and incubate at 300-500 rpm and 30-50℃ for 5-15 min to obtain zinc-rich rapeseed oil premix; perform vacuum high-speed shear homogenization on the zinc-rich rapeseed oil premix, let it stand for 0.5-2 h after homogenization, filter, and obtain zinc-rich rapeseed oil.

[0012] Furthermore, the water used in this invention meets the requirements specified in GB 19304; the amount of water added should be based on the solubility of organic zinc in water to ensure that the organic zinc is uniformly dissolved in the water.

[0013] Furthermore, the concentration of the organic zinc aqueous solution in step (1) is 0.3-2 g / mL.

[0014] Furthermore, the organic zinc solid is any one or a mixture of food-grade zinc gluconate, zinc glycinate, zinc lactate, zinc citrate, zinc pyridinecarboxylate, zinc methionine, and zinc lysine.

[0015] Furthermore, in step (1), the stabilizer in the organic zinc aqueous solution containing the stabilizer accounts for 0.1-10% of the water by mass.

[0016] Furthermore, the stabilizer is any one or a mixture of food-grade starch acetate, sodium alginate, locust bean gum, xanthan gum, carrageenan, guar gum, pectin, microcrystalline cellulose, cyclodextrin, gelatin, and agar.

[0017] Furthermore, the rapeseed oil used in this invention is any one of pressed rapeseed oil, extracted rapeseed oil, low erucic acid rapeseed oil, high oleic acid rapeseed oil, and aromatic rapeseed oil.

[0018] Furthermore, the antioxidant mentioned in step (2) is any one or a mixture of tea polyphenol palmitate, licorice antioxidant, ascorbate palmitate, natural vitamin E and bamboo leaf antioxidant;

[0019] The antioxidant in the rapeseed oil premix has a mass fraction of 0.05-0.1‰.

[0020] Further, the emulsifier mentioned in step (2) is any one or a mixture of food-grade propylene glycol fatty acid ester, monoglyceride succinate, polyglycerol fatty acid ester, Tween, Span, mono- and diglyceride fatty acid esters, phospholipids, citric acid fatty acid glycerides, lactic acid fatty acid glycerides and glycerol.

[0021] The mass fraction of emulsifier in the rapeseed oil premix is ​​0.01%-1%.

[0022] Furthermore, the mass of the organic zinc aqueous solution in step (3) shall not exceed 1‰ of the mass of the rapeseed oil premix.

[0023] Furthermore, the homogenization process in step (3) is to homogenize at 2000 rpm for 1-2 minutes, then at 5000 rpm for 2-3 minutes, and then at 8000 rpm for 5-12 minutes to complete the homogenization, with a homogenization pressure of 0.1-0.5 MPa.

[0024] In the present invention, the premixed solution needs to be homogenized rapidly after incubation, while simultaneously being slowly stirred mechanically or magnetically to ensure thorough homogenization; the homogenizing head needs to be cleaned and kept dry before and after use.

[0025] The zinc-rich rapeseed oil prepared by this invention has a water content of <1‰, a zinc content of 10-140mg / kg, an acid value of ≤3.0mg / gKOH, a peroxide value of ≤0.25g / 100g, and a long-term stable zinc content. The product is clear, transparent, and free of sediment.

[0026] The zinc-enriched rapeseed oil of the present invention forms a binary stable system. Through the interaction of hydrophobic emulsifiers such as polyricinoleate and polysaccharide stabilizers at the interface, an interfacial film is formed to stabilize the oil-water interface and encapsulate organic zinc such as zinc glycinate in the aqueous solution, while simultaneously emulsifying and solubilizing it in the rapeseed oil, ultimately forming a zinc-enriched rapeseed oil product.

[0027] The beneficial effects of this invention are as follows:

[0028] 1) This invention homogenizes food-grade organic zinc aqueous solution in organic zinc aqueous solution, and uses food-grade emulsifier and polysaccharide to form an interfacial film at the oil-water interface to stabilize the oil-water interface, successfully preparing zinc-rich rapeseed oil by solubilizing organic zinc in rapeseed oil, improving the comprehensive utilization rate of raw materials and increasing the added value of products.

[0029] 2) This invention is a one-step method for preparing zinc-rich rapeseed oil. The process is relatively simple, does not require a large amount of water resources, and is easy to control the moisture content and quality of the product, laying the foundation for industrial-scale production. This invention directly uses food-grade organic zinc, which has a unique digestion and absorption pathway after human consumption, has no side effects, and is more conducive to the body's utilization.

[0030] 3) The zinc-enriched rapeseed oil prepared by this invention has a controllable zinc content, and the zinc content remains stable over a long shelf life. The method of this invention does not alter the composition and properties of the rapeseed oil; in particular, the oil's moisture content, acid value, and peroxide value all meet national standards. The shelf life is unchanged compared to blank rapeseed oil, and the zinc content is guaranteed not to decrease for at least 18 months. Attached Figure Description

[0031] Figure 1 Figures showing zinc-enriched rapeseed oils with different zinc fortification levels provided by the present invention;

[0032] Figure 2 The oxidation induction period diagram of zinc-enriched rapeseed oil with different zinc fortification levels provided by this invention.

[0033] In the accompanying drawings and tables of this invention, A, B, C, D, E, and F represent blank rapeseed oil, zinc-enriched rapeseed oil with an added amount of 1.67 mg / 100g, zinc-enriched rapeseed oil with an added amount of 3.33 mg / 100g, zinc-enriched rapeseed oil with an added amount of 6.67 mg / 100g, zinc-enriched rapeseed oil with an added amount of 10.0 mg / 100g, and zinc-enriched rapeseed oil with an added amount of 13.3 mg / 100g, respectively. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In this embodiment of the invention, the amount of organic zinc solution added can be the same as the amount of BF added in the experimental example of the invention.

[0036] Example 1

[0037] (1) Weigh 4g of zinc glycinate solid and add 6mL of water to prepare an organic zinc aqueous solution. After standing for 30min, no solid precipitates out, and the preparation is complete.

[0038] (2) Take the prepared organic zinc aqueous solution and add pectin at a concentration of 0.5wt% (pectin / water). Stir at 70°C until completely dissolved. After cooling, place in a 4°C refrigerator for full hydration, and no solid precipitates after hydration.

[0039] (3) Take 1 kg of fragrant rapeseed oil, then add 0.1‰ ascorbate palmitate and 0.05 wt% polyglycerol ricinoleate, and stir at room temperature for 15 min to mix evenly;

[0040] (4) Take out a portion of the organic zinc solution and add it dropwise to the rapeseed oil premix. Stir and incubate at 300 rpm and 50°C for 10 min to prepare a zinc-rich rapeseed oil premix.

[0041] (5) The zinc-rich rapeseed oil premix was rapidly homogenized by high-speed shearing in a homogenizer. The homogenization program was set to 2000 rpm for 1 min, 5000 rpm for 3 min, and 8000 rpm for 6 min. The homogenization pressure was 0.5 MPa. After standing and stabilizing, any solids that may be present were filtered out to obtain zinc-rich rapeseed oil.

[0042] Example 2

[0043] (1) Weigh 5g of zinc gluconate solid, add 10mL of water to prepare a zinc aqueous solution. After standing for 30min, no solid precipitates out, and the preparation is complete.

[0044] (2) Take an organic zinc aqueous solution and add xanthan gum at a concentration of 0.8wt% (xanthan gum / water). Stir at 50°C until completely dissolved. After cooling, place in a 4°C refrigerator for full hydration, and no solid precipitates after hydration.

[0045] (3) Take 1 kg of pressed rapeseed oil, add 0.1‰ tea polyphenol palmitate, and add 0.3 wt% Span. Stir at room temperature for 5 minutes to mix evenly.

[0046] (4) Take out a portion of the organic zinc solution and add it dropwise to the rapeseed oil premix. Stir and incubate at 300 rpm and 50°C for 10 min to prepare a zinc-rich rapeseed oil premix.

[0047] (5) The zinc-rich rapeseed oil premix was rapidly homogenized by high-speed shearing in a homogenizer. The homogenization program was set to 2000 rpm for 2 min, 6000 rpm for 3 min, and 8000 rpm for 5 min. The homogenization pressure was 0.1 MPa. After standing and stabilizing, any solids that may be present were filtered out to obtain zinc-rich rapeseed oil.

[0048] Example 3

[0049] (1) Weigh 5g of zinc citrate solid and add 5mL of water to prepare a zinc aqueous solution. After standing for 15min, no solid precipitates out, and the preparation is complete.

[0050] (2) Take an organic zinc aqueous solution and add xanthan gum at a concentration of 0.6wt% (xanthan gum / water). Stir at 40°C until completely dissolved. After cooling, place in a 4°C refrigerator for full hydration, and no solid precipitates after hydration.

[0051] (3) Take 1 kg of low erucic acid rapeseed oil, add 0.1‰ tea polyphenol palmitate and 0.2 wt% succinic acid monoglyceride, stir at room temperature for 5 min to mix evenly;

[0052] (4) Take out a portion of the organic zinc solution and add it dropwise to the rapeseed oil premix. Incubate at 50°C for 10 min under stirring at 300 rpm to prepare a zinc-rich rapeseed oil premix.

[0053] (5) The zinc-rich rapeseed oil premix was rapidly homogenized by high-speed shearing in a homogenizer. The homogenization program was set to 2000 rpm for 2 min, 5000 rpm for 4 min, and 8000 rpm for 4 min. The homogenization pressure was 0.3 MPa. After standing and stabilizing, any solids that may be present were filtered out to obtain zinc-rich rapeseed oil.

[0054] Example 4

[0055] (1) Weigh 5g of zinc lactate solid and add 9mL of water to prepare an organic zinc aqueous solution. After standing for 10min, no solid precipitates out, and the preparation is complete.

[0056] (2) Take an organic zinc aqueous solution and add carrageenan at a concentration of 0.9wt% (carrageenan / water). Stir at 60°C until completely dissolved, cool and place in a 4°C refrigerator for full hydration, and no solid precipitates after hydration.

[0057] (3) Take 1 kg of non-GMO rapeseed oil, add 0.1‰ licorice antioxidant and 0.2 wt% succinate monoglyceride, stir at room temperature for 5 min to mix evenly;

[0058] (4) Take out a portion of the organic zinc solution and add it dropwise to the rapeseed oil premix. Stir and incubate at 300 rpm and 50°C for 15 min to prepare a zinc-rich rapeseed oil premix.

[0059] (5) The zinc-rich rapeseed oil premix was rapidly homogenized by high-speed shearing in a homogenizer. The homogenization program was set to 2000 rpm for 2 min, 5000 rpm for 4 min, and 8000 rpm for 6 min. The homogenization pressure was 0.2 MPa. After standing and stabilizing, any solids that may be present were filtered out to obtain zinc-rich rapeseed oil.

[0060] Example 5

[0061] (1) Weigh 5g of zinc methionine solid and add 8mL of water to prepare a zinc aqueous solution. After standing for 15min, no solid precipitates out, and the preparation is complete.

[0062] (2) Take an organic zinc aqueous solution and add guar gum at a concentration of 0.1wt% (guar gum / water). Stir at 40°C until completely dissolved. After cooling, place in a 4°C refrigerator for full hydration, and no solid precipitates after hydration.

[0063] (3) Take 1 kg of fragrant rapeseed oil, add 0.1‰ natural vitamin E and 0.5 wt% polyglycerol fatty acid ester, stir at room temperature for 5 min to mix evenly;

[0064] (4) Take out a portion of the organic zinc solution and add it dropwise to the rapeseed oil premix. Stir and incubate at 300 rpm and 50°C for 10 min to prepare a zinc-rich rapeseed oil premix.

[0065] (5) The zinc-rich rapeseed oil premix was rapidly homogenized by high-speed shearing in a homogenizer. The homogenization program was set to 2000 rpm for 1 min, 5000 rpm for 3 min, and 8000 rpm for 6 min. The homogenization pressure was 0.4 MPa. After standing and stabilizing, any solids that may be present were filtered out to obtain zinc-rich rapeseed oil.

[0066] Experimental Example 1

[0067] According to the preparation method of Example 1 of the present invention, an organic zinc solution was added according to the amount of Zn added as described in Table 1 to form zinc-rich rapeseed oil. The obtained zinc-rich rapeseed oil was tested, and the results are shown in Table 1.

[0068]

[0069] Table 1 provides the actual addition amount, test amount, retention rate, acid value, and peroxide value of zinc-enriched rapeseed oil with different zinc fortification levels. The results show that the zinc retention rate of the zinc-enriched rapeseed oil prepared by the method of this invention is greater than 50%, and the acid value and peroxide value meet the national standards for rapeseed oil. Furthermore, the method provided by this invention... Figure 1 This indicates that the zinc-enriched rapeseed oil prepared by this invention is clear and bright in color, and the zinc fortification does not change the appearance of the rapeseed oil itself. Figure 2 This demonstrates that the zinc fortification in the method of the present invention does not affect the shelf life of the zinc-rich rapeseed oil itself.

[0070] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing zinc-enriched rapeseed oil, characterized in that, Includes the following steps: (1) Preparation of organic zinc solution: Weigh the organic zinc solid, add water to prepare an organic zinc aqueous solution, and let it stand to confirm that no solid precipitates; take the prepared organic zinc aqueous solution, add the stabilizer, stir at 40-70℃ to dissolve completely, cool and hydrate at 4℃ for 4-12h, remove the solid precipitate after hydration to obtain the organic zinc solution for later use. (2) Preparation of rapeseed oil premix: Add antioxidant to rapeseed oil and dissolve it completely at 50-80℃. Add emulsifier and stir at room temperature for 5-15 minutes to mix evenly to obtain rapeseed oil premix for later use. (3) Two-phase mixing and homogenization: Add the organic zinc aqueous solution dropwise to the rapeseed oil premix, stir and incubate at 300-500 rpm and 30-50℃ for 5-15 min to obtain zinc-rich rapeseed oil premix; perform vacuum high-speed shear homogenization on the zinc-rich rapeseed oil premix, let it stand for 0.5-2 h after homogenization, filter, and obtain zinc-rich rapeseed oil; The concentration of the organic zinc aqueous solution in step (1) is 0.3-2 g / mL; In step (1), the stabilizer in the organic zinc aqueous solution containing the stabilizer accounts for 0.1-10% of the water by mass. The stabilizer is any one or a mixture of food-grade starch acetate, sodium alginate, locust bean gum, xanthan gum, carrageenan, guar gum, pectin, microcrystalline cellulose, cyclodextrin, gelatin and agar; The antioxidant mentioned in step (2) is any one or a mixture of tea polyphenol palmitate, licorice antioxidant, ascorbate palmitate, natural vitamin E and bamboo leaf antioxidant; The antioxidant in the rapeseed oil premix is ​​0.05-0.1‰ by mass. The emulsifier mentioned in step (2) is any one or a mixture of food-grade propylene glycol fatty acid ester, monoglyceride succinate, polyglycerol fatty acid ester, Tween, Span, mono- and diglyceride fatty acid esters, phospholipids, glycerides of citrate fatty acid, glycerides of lactate fatty acid, and glycerol. The mass fraction of emulsifier in the rapeseed oil premix is ​​0.01%-1%; The organic zinc aqueous solution mentioned in step (3) accounts for no more than 1‰ of the rapeseed oil premix. The homogenization process described in step (3) is to homogenize at 2000 rpm for 1-2 min, then at 5000 rpm for 2-3 min, and then at 8000 rpm for 5-12 min to complete the homogenization. The homogenization pressure is 0.1-0.5 MPa. The zinc-rich rapeseed oil has a water content of <1‰.

2. The method for preparing zinc-rich rapeseed oil according to claim 1, characterized in that, The organic zinc solid is any one or a mixture of food-grade zinc gluconate, zinc glycinate, zinc lactate, zinc citrate, zinc pyridinecarboxylate, zinc methionine, and zinc lysine.

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