Natural plant extract food antioxidant additive and preparation method thereof

Abstract

The invention relates to a natural plant extract food antioxidant additive and a preparation method thereof, the natural plant extract food antioxidant additive comprises a core material and a wall material, and the core material comprises the following components by mass: 10-20 parts of a polyphenol compound, 10-15 parts of a polysaccharide compound and 20-30 parts of a flavonoid compound. The preparation method comprises the following steps: mixing sodium alginate and a polysaccharide compound to prepare a polysaccharide microcapsule; mixing a polyphenol compound, a flavonoid compound and the polysaccharide micro-capsule, and dispersing with an emulsifier to obtain an emulsified dispersion liquid; and mixing a chitosan solution and a polylysine solution to obtain a mixed wall material solution, adding the mixed wall material solution into the emulsified dispersion liquid to prepare a microcapsule product, washing, and freeze-drying to obtain the food antioxidant additive of the natural plant extract. The additive has the effect of improving the anti-oxidation performance, can provide long-acting and lasting anti-oxidation protection, and has a certain health-care effect.

Description

Technical Field

[0001] The present application relates to the technical field of additives, and in particular to a food antioxidant additive of natural plant extracts and a preparation method thereof. Background Art

[0002] As an important ingredient, food additives are widely used in food processing to improve the taste, color and nutritional value of food. With the improvement of consumers' health awareness and the increasingly stringent food safety regulations, traditional chemical additives have received more and more attention due to their possible impact on human health. Relatively speaking, biological additives have gradually become one of the research hotspots of food preservation technology due to their advantages such as "greenness", "safety" and "naturalness", and are of great significance for improving food safety and nutritional value.

[0003] At present, in order to solve the negative impact of chemical additives on health, the relevant technical field has begun to focus on the use of natural plant extracts as food antioxidant additives. The relevant technology obtains antioxidant components in plants through solvent extraction, supercritical carbon dioxide extraction or enzymatic extraction. In addition, in order to better apply them to food, the above-mentioned plant antioxidant components are often mixed with food carriers such as edible oil, starch or protein. Common mixing methods include stirring, spray drying or freeze drying.

[0004] However, food antioxidant additives prepared from natural plant extracts in the prior art generally have the problem of low antioxidant efficiency. Especially in actual application environments, the antioxidant performance often cannot meet the needs of long-term preservation, so it needs to be improved. Summary of the invention

[0005] In order to improve the long-term antioxidant performance of the additive, the present application provides a food antioxidant additive of natural plant extracts and a preparation method thereof.

[0006] The present application provides a food antioxidant additive of natural plant extract and a preparation method thereof using the following technical scheme: In the first aspect, the present application provides a food antioxidant additive of natural plant extracts, which adopts the following technical scheme: a food antioxidant additive of natural plant extracts, comprising a core material and a wall material, wherein the core material comprises the following components in parts by weight: 10-20 parts of polyphenols Polysaccharide compounds 10-15 parts 20-30 parts of flavonoids.

[0007] Polyphenol compounds have strong free radical scavenging ability and can effectively inhibit oxidation reactions in food; polysaccharide compounds not only have certain antioxidant activity themselves, but also enhance the stability and utilization rate of other antioxidant ingredients; flavonoids exert antioxidant effects through various mechanisms such as inhibiting oxidase activity and chelating metal ions. These three ingredients are combined in a specific proportion to synergistically exhibit high-efficiency and broad-spectrum antioxidant effects; the wall material plays a protective role and can effectively ensure the stability of the active ingredients in the core material and control its release rate, which can significantly delay the oxidation and rancidity of food, maintain the nutritional content of food for a long time, and extend the shelf life of food; at the same time, these substances have health benefits for the human body, can effectively fight free radicals, reduce the oxidative damage of free radicals to cells, and thus reduce the risk of cell aging and pathology.

[0008] Preferably, the polyphenolic compounds include tocopherol, anthocyanin and peel polyphenol extract.

[0009] Tocopherol has good fat solubility and prevents lipid oxidation by capturing free radicals; anthocyanins can play an antioxidant role by regulating the redox signaling pathway in cells, and the multiple phenolic hydroxyl groups in its molecular structure can provide hydrogen atoms to terminate free radical chain reactions; peel polyphenol extracts are rich in a variety of phenolic substances, which can reduce the occurrence of catalytic oxidation reactions by chelating with metal ions. These three work together to play an antioxidant role in multiple ways, significantly enhancing the overall antioxidant efficacy of polyphenol compounds, thereby more effectively delaying food oxidation and ensuring food quality.

[0010] Preferably, the peel polyphenol extract is prepared by the following steps: The peel is dried to constant weight, crushed and sieved to obtain peel powder, dispersed in ethanol solution, microwave treated, extracted in a water bath, centrifuged after extraction to obtain peel extraction supernatant, concentrated by rotary evaporation, and freeze-dried to obtain peel polyphenol extract.

[0011] The peel polyphenol extract prepared according to the above steps has high purity and strong antioxidant activity, and can effectively improve the performance of food antioxidant additives.

[0012] Preferably, the peel comprises one or more of mango peel, kidney bean peel and grape peel.

[0013] Mango peel, kidney bean peel and grape peel are rich in various polyphenol components with antioxidant activity and have unique antioxidant mechanisms. Extracting polyphenols from these peels not only achieves effective utilization of waste and reduces costs, but also because of their unique polyphenol composition and structure, they complement and synergize with each other, making the extracted peel polyphenol extracts have richer antioxidant components and stronger antioxidant efficacy, thereby further optimizing the performance of food antioxidant additives and achieving long-term antioxidant protection.

[0014] Preferably, the polysaccharide compounds include Rosa laevigata polysaccharide and Pleurotus eryngii polysaccharide.

[0015] Golden Rosa rugosa polysaccharide has good biocompatibility and stability, and can enhance the dispersibility of antioxidant additives in food systems. At the same time, its own antioxidant activity helps to synergistically enhance the overall antioxidant effect; mushroom polysaccharides not only have antioxidant properties, but can also regulate the immune system and enhance the health function of food; these two polysaccharide compounds work synergistically to effectively improve the antioxidant properties of food antioxidant additives.

[0016] Preferably, the Rosa laevigata polysaccharide is prepared by the following steps: The Rosa laevigata fruit is dried to constant weight, crushed and sieved to obtain Rosa laevigata fruit powder, added into enzyme solution for extraction, inactivated after extraction, separated and concentrated, precipitated with ethanol, deproteinized, subjected to secondary alcohol precipitation, and freeze-dried to obtain Rosa laevigata fruit polysaccharide.

[0017] Preferably, the mushroom polysaccharide is prepared by the following steps: The mushrooms are dried to constant weight, crushed and sieved to obtain mushroom powder, the mushroom powder is dispersed in water to obtain a liquid, microwave-treated, extracted in a water bath, centrifuged after the extraction to obtain a mushroom polysaccharide supernatant, the mushroom polysaccharide supernatant is precipitated with ethanol, the precipitate is collected by centrifugation, and freeze-dried to obtain mushroom polysaccharide.

[0018] Extracting golden cherry polysaccharide and mushroom polysaccharide through the above steps can effectively improve the purity and activity of the polysaccharides, synergistically enhance the antioxidant properties, and improve the preservation effect and quality stability of food.

[0019] Preferably, the flavonoids include quercetin, catechin, soy flavonoids and rutin.

[0020] Quercetin has a strong free radical scavenging ability. It can quickly capture and neutralize harmful free radicals in food, prevent the chain reaction of oxidation reactions, and effectively delay the oxidation and deterioration of food; catechins can inhibit the activity of oxidases, reduce the initiation of oxidation reactions, and reduce the risk of food oxidation; soy flavonoids enhance antioxidant properties by scavenging free radicals and chelating metal ions; rutin chelates metal ions to avoid the catalytic promotion of oxidation reactions by metal ions. The combined effect of these four substances makes the prepared food antioxidant have comprehensive and efficient antioxidant properties.

[0021] Preferably, the wall material comprises chitosan, sodium alginate and polylysine.

[0022] Sodium alginate has good stability and gel properties, which provides tight protection for the antioxidant components in the core material and effectively blocks the direct contact between the internal components and adverse external factors; chitosan can be further embedded through electrostatic interaction, and its good film-forming property strengthens the overall protective structure, enhances the barrier properties of the wall material, and more effectively prevents the loss and deterioration of antioxidant components. Polylysine doped chitosan not only exerts its own antibacterial effect, inhibits the growth of microorganisms, and reduces the adverse effects of microorganisms on additives, but also synergizes with chitosan to further enhance the comprehensive protective performance of the wall material.

[0023] In a second aspect, the present application provides a method for preparing a food antioxidant additive of natural plant extracts, using the following technical scheme: A method for preparing a food antioxidant additive of natural plant extracts comprises the following steps: Dissolving sodium alginate and polysaccharide compounds in water to obtain a mixed solution, injecting the mixed solution into a calcium chloride solution, and filtering after the reaction to obtain polysaccharide microcapsules; The polyphenol compounds and flavonoid compounds are mixed and dispersed in a mixed solvent of petroleum ether and ethanol aqueous solution, Tween-80, Span-80 and the polysaccharide microcapsules prepared above are added, the pH is adjusted to acidic, and an emulsified dispersion liquid is obtained after stirring and dispersion; chitosan is dissolved in an acetic acid aqueous solution to obtain a chitosan solution, polylysine is dissolved in water to obtain a polylysine solution, the chitosan solution and the polylysine solution are mixed to obtain a mixed wall material solution, the mixed wall material solution is added to the emulsified dispersion liquid, stirring is performed while adding, centrifuging to obtain a microcapsule product after the reaction, washing the microcapsule product with water three times, and freeze-drying to obtain a food antioxidant additive of a natural plant extract.

[0024] The additive prepared according to the above steps has good antioxidant properties and can exert its effect for a long time.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. Polyphenol compounds, with their powerful free radical scavenging ability, effectively inhibit oxidation reactions in food; polysaccharides not only have certain antioxidant activity themselves, but also enhance the stability and bioavailability of other antioxidant ingredients; flavonoids exert antioxidant effects through various mechanisms such as inhibiting oxidase activity and chelating metal ions. These three ingredients are combined in a specific proportion to synergistically exhibit efficient and broad-spectrum antioxidant effects; wall materials play a key protective role, which can effectively ensure the stability of active ingredients in the core material and control its release rate, which can significantly delay the oxidation and rancidity of food, maintain the nutritional content of food for a long time, and extend the shelf life of food; at the same time, these substances have health benefits for the human body, can effectively fight free radicals, reduce the oxidative damage of free radicals to cells, and thus reduce the risk of cell aging and pathology.

[0026] 2. Tocopherol has good fat solubility and prevents lipid oxidation by capturing free radicals; anthocyanins can exert antioxidant effects by regulating the redox signaling pathways in cells, and the multiple phenolic hydroxyl groups in their molecular structure can provide hydrogen atoms to terminate free radical chain reactions; peel polyphenol extracts are rich in a variety of phenolic substances, which can chelate with metal ions to reduce the occurrence of catalytic oxidation reactions; these three work synergistically to exert antioxidant effects from multiple pathways, significantly enhancing the overall antioxidant efficacy of polyphenol compounds, thereby more effectively delaying food oxidation and ensuring food quality.

[0027] 3. Golden Rosa rugosa polysaccharide has good biocompatibility and stability, which can enhance the dispersibility of antioxidant additives in the food system. At the same time, its own antioxidant activity helps to synergistically enhance the overall antioxidant effect; mushroom polysaccharides not only have antioxidant properties, but can also regulate the immune system and enhance the health function of food; these two polysaccharide compounds work synergistically to effectively improve the antioxidant properties of food antioxidant additives. DETAILED DESCRIPTION

[0028] The present application discloses a food antioxidant additive of natural plant extract and a preparation method thereof. The raw materials used in the present application can be obtained from commercially available raw materials unless otherwise specified. The present application is further described in detail in conjunction with the examples below: Ingredients: Mango peel is the peel of Tainong mango, kidney beans are produced in Inner Mongolia, grape skin is the peel of Kyoho grape, golden cherry is produced in Jiangsu, mushroom is shiitake mushroom, Tween-80 (CAS No.: 9005-65-6), Span-80 (CAS No.: 1338-43-8), tocopherol (CAS No.: 1406-18-4), anthocyanin (CAS No.: 528-58-5), quercetin (CAS No.: 117-39-5), catechin (CAS No.: 154-23-4), soybean flavonoids (CAS No.: 486-66-8), rutin (CAS No.: 153-18-4), sodium alginate (CAS No.: 9005-38-3), chitosan (CAS No.: 9012-76-4), polylysine (CAS No.: 25104-18-1).

[0029] Example 1 Preparation of mango peel polyphenol extract The mango peel was dried to constant weight and crushed through an 80-mesh sieve to obtain mango peel powder. The mango peel powder was dispersed in an ethanol solution with a volume content of 60% at a solid-liquid ratio of 1:30 (g / mL). The solution was microwaved at a microwave power of 160 W for 30 seconds and extracted in a 60°C water bath for 30 minutes. After the extraction was completed, the solution was centrifuged to obtain a mango peel extraction supernatant. The mango peel extraction supernatant was concentrated by rotary evaporation and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0030] Preparation of Kidney Bean Peel Polyphenol Extract The kidney beans were washed and soaked, and then the embryos were removed to obtain the kidney bean peels. The kidney bean peels were dried to constant weight, and then crushed through an 80-mesh sieve to obtain kidney bean peel powder. The kidney bean peel powder was dispersed in an ethanol solution with a volume content of 60% and a solid-liquid ratio of 1:60 (g / mL). After microwave treatment at a microwave power of 600 W for 40 seconds, the solution was extracted in a 60°C water bath for 50 minutes. After the extraction was completed, the solution was centrifuged to obtain a kidney bean peel extraction supernatant, and the kidney bean peel extraction supernatant was concentrated by rotary evaporation, and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0031] Preparation of grape skin polyphenol extract The grape peel was dried to constant weight and crushed through an 80-mesh sieve to obtain grape peel powder, which was dispersed in an ethanol solution with a volume content of 50% at a solid-liquid ratio of 1:30 (g / L). The solution was microwaved at a microwave power of 540 W for 80 seconds and extracted in a 60°C water bath for 60 minutes. After the extraction was completed, the solution was centrifuged to obtain a grape peel extraction supernatant, which was concentrated by rotary evaporation and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0032] Preparation of Rosa Laevigata Polysaccharide The Rosa laevigata fruit is dried to constant weight, crushed and passed through an 80-mesh sieve to obtain Rosa laevigata powder, and the Rosa laevigata powder is added to an enzyme solution for extraction, with a solid-liquid ratio of 1:20. The enzyme solution contains 2% of a composite enzyme by mass, and the mass ratio of cellulase, pectinase and papain in the composite enzyme is 1:1:1. The pH is adjusted to 4.5, extracted at 45°C for 50 minutes, inactivated at 100°C after extraction, separated and concentrated, precipitated with ethanol, deproteinized, subjected to secondary alcohol precipitation, and freeze-dried at -20°C to obtain Rosa laevigata polysaccharide.

[0033] Preparation of mushroom polysaccharides The mushrooms were dried to constant weight, crushed and sieved to obtain mushroom powder, which was dispersed in water with a solid-liquid ratio of 1:40 (g / mL). Microwave-assisted extraction was performed at a microwave power of 540 W for 40 seconds, and the mixture was extracted in a 60°C water bath for 3 hours. After the extraction, the mushroom polysaccharide supernatant was obtained by centrifugation. The mushroom polysaccharide supernatant was precipitated with ethanol, the precipitate was collected by centrifugation, and freeze-dried at -20°C to obtain mushroom polysaccharide.

[0034] Preparation of food antioxidant additives from natural plant extracts 15g of sodium alginate and 10g of polysaccharide compounds were dissolved in 750mL of deionized water to obtain a mixed solution, in which the mass ratio of golden cherry polysaccharide to mushroom polysaccharide in the polysaccharide compounds was 1:1. The mixed solution was injected into a 2% calcium chloride solution by mass at a rate of 1mL / min through a 0.5mm nozzle, with the nozzle being 5cm away from the surface of the calcium chloride solution. After the injection was completed, the mixture was reacted for 5min and filtered to obtain polysaccharide microcapsules.

[0035] 10 g of polyphenol compounds and 30 g of flavonoid compounds were mixed and dispersed in 500 mL of a 1:1 volume ratio of petroleum ether and a 50% volume content of ethanol aqueous solution, 30 g of Tween-80, 15 g of Span-80 and the above-prepared polysaccharide microcapsules were added, the pH was adjusted to 4, and the mixture was stirred at a speed of 5000 rpm for 30 min to obtain an emulsified dispersion. The mass ratio of tocopherol, anthocyanin and peel polyphenol extract in the above polyphenol compounds was 1:1.2:2, the mass ratio of mango peel polyphenol extract, kidney bean peel polyphenol extract and grape skin polyphenol extract in the peel polyphenol extract was 1:0.8:1.5, and the mass ratio of quercetin, catechins, soybean extract and safflower oil in the above flavonoid compounds was 1:1.2:2. The mass ratio of flavonoids to rutin is 1:1.5:0.75:0.5; 90g of chitosan is dissolved in 500ml of acetic acid aqueous solution with a mass percentage of 2.5% to obtain a chitosan solution; 30g of polylysine is dissolved in 100ml of deionized water to obtain a polylysine solution; the chitosan solution and the polylysine solution are mixed to obtain a mixed wall material solution; the mixed wall material solution is added to an emulsified dispersion liquid, and the addition is completed within 15min. While adding, the mixture is stirred at a speed of 500rpm, and the reaction is continued for 10min. The microcapsule product is obtained by centrifugation, and the microcapsule product is washed three times with deionized water, and then freeze-dried at -20°C to obtain a food antioxidant additive of a natural plant extract.

[0036] Example 2 Preparation of mango peel polyphenol extract The mango peel was dried to constant weight and crushed through an 80-mesh sieve to obtain mango peel powder. The mango peel powder was dispersed in an ethanol solution with a volume content of 60% at a solid-liquid ratio of 1:30 (g / mL). The solution was microwaved at a microwave power of 160 W for 30 seconds and extracted in a 60°C water bath for 30 minutes. After the extraction was completed, the solution was centrifuged to obtain a mango peel extraction supernatant. The mango peel extraction supernatant was concentrated by rotary evaporation and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0037] Preparation of Kidney Bean Peel Polyphenol Extract The kidney beans were washed and soaked, and then the embryos were removed to obtain the kidney bean peels. The kidney bean peels were dried to constant weight, and then crushed through an 80-mesh sieve to obtain kidney bean peel powder. The kidney bean peel powder was dispersed in an ethanol solution with a volume content of 60% and a solid-liquid ratio of 1:60 (g / mL). After microwave treatment at a microwave power of 600 W for 40 seconds, the solution was extracted in a 60°C water bath for 50 minutes. After the extraction was completed, the solution was centrifuged to obtain a kidney bean peel extraction supernatant, and the kidney bean peel extraction supernatant was concentrated by rotary evaporation, and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0038] Preparation of grape skin polyphenol extract The grape peel was dried to constant weight and crushed through an 80-mesh sieve to obtain grape peel powder, which was dispersed in an ethanol solution with a volume content of 50% at a solid-liquid ratio of 1:30 (g / L). The solution was microwaved at a microwave power of 540 W for 80 seconds and extracted in a 60°C water bath for 60 minutes. After the extraction was completed, the solution was centrifuged to obtain a grape peel extraction supernatant, which was concentrated by rotary evaporation and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0039] Preparation of Rosa Laevigata Polysaccharide The Rosa laevigata fruit is dried to constant weight and crushed to pass through an 80-mesh sieve to obtain Rosa laevigata powder, which is added to an enzyme solution for extraction at a solid-liquid ratio of 1:20. The enzyme solution contains 2% of a composite enzyme by mass, and the mass ratio of cellulase, pectinase and papain in the composite enzyme is 1:1:1. The pH is adjusted to 4.5, and the mixture is extracted at 45°C for 50 minutes. After the extraction, the mixture is inactivated at 100°C, separated and concentrated, and precipitated with ethanol. After deproteinization, a secondary alcohol precipitation is performed, and Rosa laevigata polysaccharide is obtained after freeze-drying at -20°C.

[0040] Preparation of mushroom polysaccharides The mushrooms were dried to constant weight, crushed and sieved to obtain mushroom powder, which was dispersed in water with a solid-liquid ratio of 1:40 (g / mL). Microwave-assisted extraction was performed at a microwave power of 540 W for 40 seconds, and the mixture was extracted in a 60°C water bath for 3 hours. After the extraction, the mushroom polysaccharide supernatant was obtained by centrifugation. The mushroom polysaccharide supernatant was precipitated with ethanol, the precipitate was collected by centrifugation, and freeze-dried at -20°C to obtain mushroom polysaccharide.

[0041] Preparation of food antioxidant additives from natural plant extracts 25g of sodium alginate and 15g of polysaccharide compounds were dissolved in 750mL of deionized water to obtain a mixed solution, in which the mass ratio of Rosa laevigata polysaccharide to mushroom polysaccharide in the polysaccharide compounds was 1:1. The mixed solution was injected into a 2% calcium chloride solution by mass at a rate of 1mL / min through a 0.5mm nozzle, with the nozzle being 5cm away from the surface of the calcium chloride solution. After the injection was completed, the mixture was reacted for 5min and filtered to obtain polysaccharide microcapsules.

[0042] 20 g of polyphenol compounds and 20 g of flavonoid compounds were mixed and dispersed in 500 mL of a 1:1 volume ratio of petroleum ether and a 50% volume content of ethanol aqueous solution, 30 g of Tween-80, 15 g of Span-80 and the above-prepared polysaccharide microcapsules were added, the pH was adjusted to 4, and the mixture was stirred at a speed of 5000 rpm for 30 min to obtain an emulsified dispersion, wherein the mass ratio of tocopherol, anthocyanin and peel polyphenol extract in the above polyphenol compounds was 1:1.2:2, the mass ratio of mango peel polyphenol extract, kidney bean peel polyphenol extract and grape skin polyphenol extract in the peel polyphenol extract was 1:0.8:1.5, the mass ratio of quercetin, catechins and soybean yellow in the above flavonoids was 1:1.2:2. The mass ratio of ketone to rutin is 1:1.5:0.75:0.5; 100g of chitosan is dissolved in 500mL of acetic acid aqueous solution with a mass percentage of 2.5% to obtain a chitosan solution; 40g of polylysine is dissolved in 100mL of deionized water to obtain a polylysine solution; the chitosan solution and the polylysine solution are mixed to obtain a mixed wall material solution; the mixed wall material solution is added to the emulsified dispersion liquid, and the addition is completed within 15 minutes. While adding, the mixture is stirred at a speed of 500rpm, and the reaction is continued for 10 minutes. The microcapsule product is centrifuged to obtain the microcapsule product, and the microcapsule product is washed three times with deionized water, and then freeze-dried at -20°C to obtain a food antioxidant additive of a natural plant extract.

[0043] Example 3 Preparation of mango peel polyphenol extract The mango peel was dried to constant weight and crushed through an 80-mesh sieve to obtain mango peel powder. The mango peel powder was dispersed in an ethanol solution with a volume content of 60% at a solid-liquid ratio of 1:30 (g / mL). The solution was microwaved at a microwave power of 160 W for 30 seconds and extracted in a 60°C water bath for 30 minutes. After the extraction was completed, the solution was centrifuged to obtain a mango peel extraction supernatant. The mango peel extraction supernatant was concentrated by rotary evaporation and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0044] Preparation of Kidney Bean Peel Polyphenol Extract The kidney beans were washed and soaked, and then the embryos were removed to obtain the kidney bean peels. The kidney bean peels were dried to constant weight, and then crushed through an 80-mesh sieve to obtain kidney bean peel powder. The kidney bean peel powder was dispersed in an ethanol solution with a volume content of 60% and a solid-liquid ratio of 1:60 (g / mL). After microwave treatment at a microwave power of 600 W for 40 seconds, the solution was extracted in a 60°C water bath for 50 minutes. After the extraction was completed, the solution was centrifuged to obtain a kidney bean peel extraction supernatant, and the kidney bean peel extraction supernatant was concentrated by rotary evaporation, and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0045] Preparation of grape skin polyphenol extract The grape peel was dried to constant weight and crushed through an 80-mesh sieve to obtain grape peel powder, which was dispersed in an ethanol solution with a volume content of 50% at a solid-liquid ratio of 1:30 (g / L). The solution was microwaved at a microwave power of 540 W for 80 seconds and extracted in a 60°C water bath for 60 minutes. After the extraction was completed, the solution was centrifuged to obtain a grape peel extraction supernatant, which was concentrated by rotary evaporation and freeze-dried at -20°C to obtain a peel polyphenol extract.

[0046] Preparation of Rosa Laevigata Polysaccharide The Rosa laevigata fruit is dried to constant weight, crushed and passed through an 80-mesh sieve to obtain Rosa laevigata powder, and the Rosa laevigata powder is added to an enzyme solution for extraction, with a solid-liquid ratio of 1:20. The enzyme solution contains 2% of a composite enzyme by mass, and the mass ratio of cellulase, pectinase and papain in the composite enzyme is 1:1:1. The pH is adjusted to 4.5, extracted at 45°C for 50 minutes, inactivated at 100°C after extraction, separated and concentrated, precipitated with ethanol, deproteinized, subjected to secondary alcohol precipitation, and freeze-dried at -20°C to obtain Rosa laevigata polysaccharide.

[0047] Preparation of mushroom polysaccharides The mushrooms were dried to constant weight, crushed and sieved to obtain mushroom powder, which was dispersed in water with a solid-liquid ratio of 1:40 (g / mL). Microwave-assisted extraction was performed at a microwave power of 540 W for 40 seconds, and the mixture was extracted in a 60°C water bath for 3 hours. After the extraction, the mushroom polysaccharide supernatant was obtained by centrifugation. The mushroom polysaccharide supernatant was precipitated with ethanol, the precipitate was collected by centrifugation, and freeze-dried at -20°C to obtain mushroom polysaccharide.

[0048] Preparation of food antioxidant additives from natural plant extracts 20g of sodium alginate and 12.5g of polysaccharide compounds were dissolved in 750mL of deionized water to obtain a mixed solution, in which the mass ratio of golden cherry polysaccharide and mushroom polysaccharide in the polysaccharide compounds was 1:1. The mixed solution was injected into a 2% calcium chloride solution by mass at a rate of 1mL / min through a 0.5mm nozzle, and the nozzle was 5cm away from the surface of the calcium chloride solution. After the injection was completed, the mixture was reacted for 5min and filtered to obtain polysaccharide microcapsules.

[0049] 15 g of polyphenol compounds and 25 g of flavonoid compounds were mixed and dispersed in 500 mL of a 1:1 volume ratio of petroleum ether and a 50% volume content of ethanol aqueous solution, 30 g of Tween-80, 15 g of Span-80 and the above-prepared polysaccharide microcapsules were added, the pH was adjusted to 4, and the mixture was stirred at a speed of 5000 rpm for 30 min to obtain an emulsified dispersion. The mass ratio of tocopherol, anthocyanin and peel polyphenol extract in the above polyphenol compounds was 1:1.2:2, the mass ratio of mango peel polyphenol extract, kidney bean peel polyphenol extract and grape skin polyphenol extract in the peel polyphenol extract was 1:0.8:1.5, and the mass ratio of quercetin, catechins, soybean extract and safflower oil in the above flavonoid compounds was 1:1.2:2. The mass ratio of flavonoids to rutin is 1:1.5:0.75:0.5; 95g of chitosan is dissolved in 500ml of acetic acid aqueous solution with a mass percentage of 2.5% to obtain a chitosan solution; 35g of polylysine is dissolved in 100ml of deionized water to obtain a polylysine solution; the chitosan solution and the polylysine solution are mixed to obtain a mixed wall material solution; the mixed wall material solution is added to an emulsified dispersion liquid, and the addition is completed within 15min. While adding, the mixture is stirred at a speed of 500rpm, and the reaction is continued for 10min. The microcapsule product is centrifuged to obtain the microcapsule product, and the microcapsule product is washed three times with deionized water, and then freeze-dried at -20°C to obtain a food antioxidant additive of a natural plant extract.

[0050] Example 4 Example 4 is based on Example 3. The only difference between Example 4 and Example 3 is that in Example 4, no mango peel polyphenol extract is added to the polyphenol compounds.

[0051] Example 5 Example 5 is based on Example 3. The only difference between Example 5 and Example 3 is that in Example 5, kidney bean skin polyphenol extract and grape skin polyphenol extract are not added to the polyphenol compounds.

[0052] Example 6 Example 6 is based on Example 3. The only difference between Example 6 and Example 3 is that in Example 6, no Rosa laevigata polysaccharide is added to the polysaccharide compound.

[0053] Example 7 Example 7 is based on Example 3. The only difference between Example 7 and Example 3 is that mushroom polysaccharide is not added to the polysaccharide compound in Example 7.

[0054] Example 8 Example 8 is based on Example 3. The only difference between Example 8 and Example 3 is that quercetin is not added to the flavonoid compounds in Example 8.

[0055] Example 9 Example 9 is based on Example 3. The only difference between Example 9 and Example 3 is that soybean flavonoids and rutin are not added to the flavonoid compounds in Example 9.

[0056] Example 10 Example 10 is based on Example 3. The only difference between Example 10 and Example 3 is that in Example 10, polylysine is not added to the wall material.

[0057] Embodiment 11 Example 11 is based on Example 3. The only difference between Example 11 and Example 3 is that the mass ratio of mango peel polyphenol extract, kidney bean peel polyphenol extract and grape skin polyphenol extract in the peel polyphenol extract in Example 11 is 1:1.5:2.

[0058] Example 12 Example 12 is based on Example 3. The only difference between Example 12 and Example 3 is that the mass ratio of mango peel polyphenol extract, kidney bean peel polyphenol extract and grape skin polyphenol extract in the peel polyphenol extract in Example 12 is 1:0.8:1.5.

[0059] Comparative Example 1 Comparative Example 1 is based on Example 3, and the only difference between Comparative Example 1 and Example 3 is that Comparative Example 1 does not use wall material to embed the core material.

[0060] Performance testing Determine the antioxidant properties of food antioxidant additives from natural plant extracts: prepare 0.2mmol / L DPPH with 95% ethanol, configure the sample into a 1mg / mL dispersion, mix 100uL of the dispersion with 100uL of DPPH solution in a 96-well ELISA plate, react at room temperature and away from light for 30min, and measure the absorbance value A1 at 517nm. Use 100uL of 95% ethanol instead of DPPH solution to react with 100uL deionized water as the blank control group (A0), and use 100uL of DPPH solution to react with 100uL deionized water as the negative control group (A2). The DPPH clearance rate is calculated as follows: DPPH clearance rate (%) = (A2-A1) / (A2-A0)*100%. Each sample was tested three times, and the average value was taken after measurement. The results are recorded in Table 1.

[0061] Table 1 Test results of antioxidant properties of food antioxidant additives of natural plant extracts As can be seen from Table 1, the DPPH scavenging rates of Examples 1-3 are greater than 86.2%, which shows that the food antioxidant additives of natural plant extracts prepared in the present application have good antioxidant properties.

[0062] As can be seen from Table 1, the only difference between Examples 4-10 and Example 3 is that: in Examples 4-5, the components of the peel polyphenol extract are reduced, in Examples 6-7, the components of the polysaccharide compounds are reduced, in Examples 8-9, the components of the flavonoid compounds are reduced, and in Example 10, the components of the wall materials are reduced. Compared with Example 3, the antioxidant properties of Examples 4-10 are reduced; this is because reducing the components affects the synergistic effect between the components, thereby affecting its broad-spectrum antioxidant effect, and reducing the wall material components will affect the stability of the encapsulation, thereby affecting the antioxidant properties, so that the antioxidant properties are reduced.

[0063] As can be seen from Table 1, the only difference between Examples 11 and 12 and Example 3 is that Examples 11 and 12 change the ratio of the material composition in the peel polyphenol extract. Compared with Example 3, the antioxidant properties of Examples 11 and 12 are reduced. This is because the material composition in the peel polyphenol extract is complex, and different component dosages may lead to antagonistic or synergistic effects, so the antioxidant properties are reduced.

[0064] As can be seen from Table 1, the only difference between Comparative Example 1 and Example 3 is that in Comparative Example 1, no wall material is used to embed the core material. Compared with Example 3, the antioxidant performance of Comparative Example 1 is significantly reduced; this is because the additives obtained by directly mixing the components in the core material will quickly take effect and are easily disturbed by the external environment, affecting the antioxidant performance, lacking protection and long-term sustained release effects, and significantly reducing the antioxidant performance.

[0065] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. Through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of ​​the present application. The technical scope of the present application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A food antioxidant additive of natural plant extracts, characterized in that: It includes a core material and a wall material, wherein the core material includes the following components in parts by weight: 10-20 parts of polyphenols Polysaccharide compounds 10-15 parts 20-30 parts of flavonoids.

2. The food antioxidant additive of a natural plant extract according to claim 1, characterized in that: The polyphenolic compounds include tocopherol, anthocyanin and peel polyphenol extract.

3. The food antioxidant additive of a natural plant extract according to claim 2, characterized in that: The peel polyphenol extract is prepared by the following steps: The peel is dried to constant weight, crushed and sieved to obtain peel powder, dispersed in ethanol solution, microwave treated, extracted in a water bath, centrifuged after extraction to obtain peel extraction supernatant, concentrated by rotary evaporation, and freeze-dried to obtain peel polyphenol extract.

4. The food antioxidant additive of a natural plant extract according to claim 3, characterized in that: The fruit peel comprises one or more of mango peel, kidney bean peel and grape peel.

5. The food antioxidant additive of a natural plant extract according to claim 1, characterized in that: The polysaccharide compounds include Rosa laevigata polysaccharide and mushroom polysaccharide.

6. The food antioxidant additive of a natural plant extract according to claim 5, characterized in that: The Rosa laevigata polysaccharide is prepared by the following steps: The Rosa laevigata fruit is dried to constant weight, crushed and sieved to obtain Rosa laevigata fruit powder, added into enzyme solution for extraction, inactivated after extraction, separated and concentrated, precipitated with ethanol, deproteinized, subjected to secondary alcohol precipitation, and freeze-dried to obtain Rosa laevigata fruit polysaccharide.

7. The food antioxidant additive of a natural plant extract according to claim 5, characterized in that: The mushroom polysaccharide is prepared by the following steps: The mushrooms are dried to constant weight, crushed and sieved to obtain mushroom powder, the mushroom powder is dispersed in water to obtain a liquid, microwave-treated, extracted in a water bath, centrifuged after the extraction to obtain a mushroom polysaccharide supernatant, the mushroom polysaccharide supernatant is precipitated with ethanol, the precipitate is collected by centrifugation, and freeze-dried to obtain mushroom polysaccharide.

8. The food antioxidant additive of a natural plant extract according to claim 1, characterized in that: The flavonoids include quercetin, catechin, daidzein and rutin.

9. The food antioxidant additive of a natural plant extract according to claim 1, characterized in that: The wall material comprises chitosan, sodium alginate and polylysine.

10. A method for preparing a food antioxidant additive using a natural plant extract as claimed in any one of claims 1 to 9, characterized in that: The steps include: Dissolving sodium alginate and polysaccharide compounds in water to obtain a mixed solution, injecting the mixed solution into a calcium chloride solution, and filtering after the reaction to obtain polysaccharide microcapsules; The polyphenol compounds and flavonoid compounds are mixed and dispersed in a mixed solvent of petroleum ether and ethanol aqueous solution, Tween-80, Span-80 and the polysaccharide microcapsules prepared above are added, the pH is adjusted to acidic, and an emulsified dispersion liquid is obtained after stirring and dispersion; chitosan is dissolved in an acetic acid aqueous solution to obtain a chitosan solution, polylysine is dissolved in water to obtain a polylysine solution, the chitosan solution and the polylysine solution are mixed to obtain a mixed wall material solution, the mixed wall material solution is added to the emulsified dispersion liquid, stirring is performed while adding, centrifuging to obtain a microcapsule product after the reaction, washing the microcapsule product with water three times, and freeze-drying to obtain a food antioxidant additive of a natural plant extract.

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