Antioxidant nutritional fruit juice and preparation method thereof

Abstract

The invention relates to the technical field of food, in particular to antioxidant nutritional fruit juice and a preparation method thereof. The method comprises the following steps: S1, crushing pulp of pomegranates, blueberries, strawberries, cherries, broccoli, purple cabbages and carrots, adding a functional compound for enzymolysis, and after enzymolysis is finished, performing enzyme deactivation to obtain pretreated fruit juice; and S2, filtering the pretreated fruit juice, and degassing to obtain the antioxidant nutritional fruit juice. The antioxidant nutritional fruit juice provided by the invention can retain the original nutritional ingredients, taste and color to the greatest extent, and fruits and vegetables rich in antioxidant polyphenol substances can give full play to the effects of the fruit juice.

Description

Technical Field

[0001] The invention belongs to the technical field of food, and in particular relates to an antioxidant nutritious juice and a preparation method thereof. Background Art

[0002] In the field of life sciences and food processing, reactive oxygen species (ROS) are widely present in cells and tissues of organisms, playing an important physiological role in signal transduction and maintaining the stability of the internal environment. However, when ROS accumulate excessively, it will trigger the body's oxidative stress response, causing oxidative damage to bioactive macromolecules in cells, and then induce a variety of chronic diseases such as diabetes, hypertension, and cardiovascular disease. In addition, oxidative stress is also one of the important causes of aging.

[0003] In fruits, vitamins, organic acids and other nutrients have the ability to remove active oxygen. In the traditional fresh fruit juice processing, due to a series of complex process flows, vitamins and organic acids in the fruit raw materials are very easy to undergo oxidation reactions, which not only leads to a large loss of nutrients in the juice and a serious decline in taste, but also changes the color, ultimately causing a significant decline in the overall quality of the product.

[0004] It is worth noting that polyphenols have strong antioxidant capacity and should be able to effectively remove active oxygen in fruit and vegetable juices, slow down the oxidation process, and improve product quality. However, in actual processing and application, due to the limitations of existing technology and process conditions, antioxidant polyphenols in fruit and vegetable juices cannot fully play their due role. On the one hand, the complex processing flow may destroy the structure of polyphenols and reduce their activity; on the other hand, the lack of effective protection and enhancement technology makes it difficult to maintain their stability and antioxidant activity in fruit and vegetable juices.

[0005] For example, CN110122711A discloses a functional composite fruit and vegetable beverage containing antioxidants and a preparation method thereof. The functional composite fruit and vegetable beverage containing antioxidants includes, by weight, 25-35 parts of peanut sprouts, 25-35 parts of black bean sprouts, 8-12 parts of soybean sprouts, 8-12 parts of mung bean sprouts, 30-50 parts of oranges, 15-25 parts of apples, 15-25 parts of carrots, 0.3-1 parts of mint leaves, 0.2-0.8 parts of ginger, and 40-60 parts of water. The application adjusts the acidity of the juice by adding sodium citrate, adjusts the sweetness by adding fructose syrup and white sugar, adjusts the stability of the juice by adding sodium alginate and gelatin, and uses pasteurization technology for low-temperature sterilization, effectively reducing the loss of nutrients and antioxidant active ingredients in the production process, so that the retention rates of resveratrol and GABA are both as high as about 88%. However, the application simply uses the method of squeezing juice to extract antioxidants, and cannot completely extract the antioxidants in fruits and vegetables.

[0006] For example, CN113439809A provides a liquid preparation with antioxidant and anti-fatigue functions and a preparation method thereof. The liquid preparation provided by the present invention comprises raw materials including: 40-80 parts of blueberry juice, 10-30 parts of pineapple juice, 10-30 parts of mango juice, 30-70 parts of taurine, 80-100 parts of L-carnitine, and 2-6 parts of nicotinamide. The liquid preparation prepared by the application has good stability and small particle size, which can effectively improve the defense ability of the body's antioxidant system and thus play an anti-fatigue role. However, anthocyanins in blueberry juice and bromelain in pineapple juice may compete for intestinal absorption sites and reduce bioavailability. The absorption mechanism of carotenoids (fat soluble) and taurine (water soluble) in mango juice is different, resulting in poor antioxidant effect.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The purpose of the present invention is to provide an antioxidant nutritious juice and a preparation method thereof. The antioxidant nutritious juice provided by the present invention can retain the original nutritional components, taste and color to the greatest extent, so that fruits and vegetables rich in antioxidant polyphenols can fully exert their efficacy.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] In a first aspect, an embodiment of the present invention provides a method for preparing an antioxidant nutritious juice, comprising the following steps:

[0011] S1, crushing the pulp of pomegranate, blueberry, strawberry, cherry, broccoli, purple cabbage and carrot, adding the functionalized complex for enzymatic hydrolysis, and then inactivating the enzyme after the enzymatic hydrolysis to obtain pretreated juice;

[0012] S2, filtering the pretreated juice, and then degassing to obtain antioxidant nutritious juice.

[0013] The present invention significantly enhances the antioxidant effect through multi-dimensional synergistic effects of polyphenols in mixed juices such as pomegranates and blueberries: first, different polyphenols play complementary roles against specific free radicals, such as ellagic acid in pomegranates to remove hydroxyl radicals, anthocyanins in blueberries to remove superoxide anion radicals, and the mixture covers a wider range of free radical removal; on this basis, polyphenols promote each other through electron transfer or hydrogen atom transfer mechanisms, such as strawberry catechins provide hydrogen atoms to stabilize free radicals, and blueberry anthocyanins disperse free radical electrons through a conjugated system, synergistically improving the removal efficiency by more than 40%. Secondly, polyphenols combine chelated iron, copper and other metal ions, such as quercetin in broccoli and anthocyanins in purple cabbage to bind Fe2+ and Cu2+, respectively, blocking the Fenton reaction chain, and the metal ion binding capacity of mixed juice is 25%-30% higher than that of single juice. Further, polyphenols form a multi-pathway defense system by activating antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). In addition, polyphenols are embedded in the lipid layer of cell membranes to inhibit lipid peroxidation (for example, blueberry anthocyanins and pomegranate ellagic acid synergize to inhibit MDA by 78%), while repairing oxidatively damaged DNA (for example, broccoli and purple cabbage metabolites activate the DNA repair enzyme OGG1). Ultimately, the total antioxidant capacity (ORAC value) of mixed juices can reach 1.8-2.3 times that of a single juice, reflecting the synergistic network effect of polyphenols in molecular complementarity, metabolic regulation and physical protection.

[0014] Specifically, in terms of scavenging free radicals, ellagic acid, anthocyanidins, etc. in pomegranate juice, anthocyanidins, flavonols, etc. in blueberry juice, anthocyanidins, catechins, etc. in strawberry juice, anthocyanidins, anthocyanins, etc. in cherry juice, quercetin, kaempferol, etc. in broccoli juice, anthocyanins, flavonoids, etc. in purple cabbage juice, flavonoids in carrot juice and other polyphenols have different structures and can play a role in different types of free radicals. The ellagic acid in pomegranate has a good scavenging ability for hydroxyl radicals, and the anthocyanidins in blueberries have a significant scavenging effect on superoxide radicals. After mixing a variety of fruit and vegetable juices, different polyphenols cooperate with each other to more comprehensively remove various free radicals in the body. And when these fruit and vegetable juices are mixed, the polyphenols therein may synergistically enhance the scavenging ability for free radicals through mechanisms such as electron transfer or hydrogen atom transfer. The catechins in strawberries can stabilize free radicals by providing hydrogen atoms, while the anthocyanins in blueberries can disperse the electrons of free radicals through a conjugated system. The combination of the two may make free radical scavenging more efficient.

[0015] In terms of chelating metal ions, the polyphenols in these fruit and vegetable juices can chelate metal ions such as iron and copper, reducing the production of free radicals induced by metal ions. Quercetin in broccoli and anthocyanins in purple cabbage both have certain metal ion chelating capabilities. They can chelate a variety of metal ions in a mixed juice system, reducing the production of free radicals from the source, and have a wider range of effects than polyphenols in a single juice. At the same time, the chelates formed by different polyphenols and metal ions have different stabilities. When multiple polyphenols coexist, they may more effectively inhibit oxidation reactions involving metal ions by forming more stable complexes with metal ions. The flavonoids in carrots and ellagic acid in pomegranates work together to make the chelation of iron ions more stable and enhance the antioxidant effect.

[0016] In terms of activating antioxidant enzymes, the polyphenols in these fruit and vegetable juices can activate the antioxidant enzyme system in the body through different pathways. The polyphenols in blueberries can activate superoxide dismutase (SOD), the polyphenols in cherries can enhance the activity of glutathione peroxidase (GSH-Px), and the polyphenols in broccoli can induce the expression of catalase (CAT). The polyphenols in a variety of fruit and vegetable juices work together to activate antioxidant enzymes from multiple aspects and form a more complete antioxidant defense system. In addition, the activation time and intensity of different polyphenols on antioxidant enzymes vary. The mixed polyphenols may maintain the activity of antioxidant enzymes at a higher level for a longer time. For example, the polyphenols in purple cabbage can quickly activate some antioxidant enzymes in the early stage, while the polyphenols in strawberries can continuously enhance the activity of enzymes in the subsequent stage, making the antioxidant effect more lasting.

[0017] In a preferred embodiment, in step S1, the method for preparing the functionalized composite comprises the following steps:

[0018] A1, mixing nano-ferroferric oxide, 3-aminopropyltriethoxysilane and a solvent for reaction, and collecting the product by magnetic separation to obtain a functional magnetic carrier;

[0019] A2, mixing p-toluenesulfonyl chloride, β-cyclodextrin and water, adjusting the pH to 10-12 for reaction to obtain mono-toluenesulfonylated β-cyclodextrin;

[0020] A3, mixing the functionalized magnetic carrier, mono-toluenesulfonated β-cyclodextrin and dimethylformamide for reaction, and obtaining the nanocarrier after magnetic separation;

[0021] A4, the nanocarrier, phosphate buffer and xylanase are mixed and shaken for loading, and then magnetically separated and washed to obtain a functionalized complex.

[0022] The functionalized complex provided by the present invention not only has a clarification function (magnetic nanoparticles), but can also be reused for magnetic separation, and can fully extract polyphenols, improve enzymatic hydrolysis efficiency, and protect the stability and biological activity of polyphenols.

[0023] Specifically, nano-iron tetroxide is first combined with 3-aminopropyl triethoxysilane, and the surface of the iron tetroxide after silanization introduces functional groups such as amino groups, which not only enhances the stability of the carrier, but also lays the foundation for subsequent connection with beta-cyclodextrin, etc. β-cyclodextrin has a unique hydrophobic cavity structure. After it is combined with functionalized iron tetroxide, it is like equipping xylanase with a navigation system and a protective cover. For fruit and vegetable cell walls rich in various polysaccharide components, beta-cyclodextrin can accurately bring xylanase to the substrate action site by virtue of its inclusion reaction, greatly enhancing the affinity of enzyme and substrate. For example, the cell walls of strawberries and blueberries contain abundant pectin and hemicellulose, and the beta-cyclodextrin on the nanocarrier can recognize and combine these polysaccharides, so that xylanase can be rapidly enzymolyzed, accelerating the reaction process and improving enzymolysis efficiency. At the same time, the silanized iron tetroxide surface provides a stable microenvironment for xylanase, which can buffer the influence of changes in factors such as external temperature and pH value on enzyme activity, and ensure that the enzyme plays an efficient role under relatively mild conditions. In addition, ferroferric oxide itself has good magnetic properties, which allows the nanocarrier loaded with xylanase to be easily separated from the juice system by an external magnetic field after the enzymatic reaction is completed. Compared with the traditional enzymatic method, this feature greatly simplifies the process. When extracting polyphenols from vegetable juices such as broccoli and purple cabbage, only a magnetic field needs to be applied after the reaction, and the enzyme-loaded nanocarriers will quickly aggregate and separate from the juice, avoiding the cumbersome separation steps such as filtration and centrifugation in traditional methods, reducing enzyme loss and time cost during the separation process. At the same time, in the process of enzymatic extraction of polyphenols, nanocarriers can also play an important role in protecting polyphenols. The inclusion effect of β-cyclodextrin combined with nano-ferroferric oxide is not only for the substrate, but also has a certain embedding and protection effect on the released polyphenols. Polyphenols such as anthocyanins, which are rich in cherries and pomegranates, are easily oxidized by contact with oxygen, light, etc. during the extraction process. The presence of nanocarriers can isolate these unfavorable factors to a certain extent and reduce the oxidation loss of polyphenols. At the same time, the functionalized complex constructed with ferroferric oxide as a carrier can create a relatively mild reaction environment during enzymatic hydrolysis. It avoids the damage to the biological activity of polyphenols by drastic conditions such as high temperature, strong acid and strong alkali in traditional extraction methods. Therefore, the polyphenols extracted in this way can better retain their original antioxidant, anti-inflammatory and other biological activities, improve the quality and efficacy of polyphenols in juice, and provide a strong guarantee for the development of high-quality polyphenol-rich fruit and vegetable juice products.

[0024] In a preferred embodiment, in step A1, the particle size of the nano-ferroferric oxide is 50-100 nm.

[0025] In a preferred embodiment, in step A1, the mass ratio of the nano-ferroferric oxide, 3-aminopropyltriethoxysilane and the solvent is 1:(5-10):(50-100).

[0026] In a preferred embodiment, in step A1, the solvent is a mixture of ethanol and water in a mass ratio of 1:1.

[0027] In a preferred embodiment, in step A1, the reaction conditions are: under nitrogen atmosphere, at 40-70° C. for 4-8 hours.

[0028] In a preferred embodiment, in step A2, the mass ratio of p-toluenesulfonyl chloride, β-cyclodextrin and water is (3-8):10:(50-100).

[0029] In a preferred embodiment, in step A2, the reaction conditions are: reaction temperature is 20-30° C., and reaction time is 2-5 h.

[0030] In a preferred embodiment, in step A3, the mass ratio of the functionalized magnetic carrier, mono-toluenesulfonated β-cyclodextrin and dimethylformamide is (2-6):1:(50-100).

[0031] In a preferred embodiment, in step A3, the reaction conditions are: under nitrogen atmosphere, at 60-90° C. for 10-18 h.

[0032] In a preferred embodiment, in step A4, the mass ratio of the nanocarrier, phosphate buffer and xylanase is 1:(50-100):(5-10).

[0033] In a preferred embodiment, in step A4, the pH of the phosphate buffer is 7.2.

[0034] In a preferred embodiment, in step A4, the oscillation time is 12-24 hours.

[0035] In a preferred embodiment, in step S1, the mass ratio of pomegranate, blueberry, strawberry, cherry, broccoli, purple cabbage and carrot is 1:(1-3):(2-4):(1-3):(2-5):(3-5):(4-6).

[0036] In a preferred embodiment, in step S1, the amount of the enzyme added is 1-2 parts relative to 100 parts by mass of the pomegranate, blueberry, strawberry, cherry, broccoli, purple cabbage, and carrot.

[0037] In a preferred embodiment, in step S1, the enzymatic hydrolysis time is 1-4 hours.

[0038] In a preferred embodiment, in step S2, filtering is performed using a 200-mesh double-layer filter cloth.

[0039] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned antioxidant nutritious juice to obtain the antioxidant nutritious juice.

[0040] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0041] 1. The present invention significantly enhances the antioxidant effect through multi-dimensional synergistic effects of polyphenols in mixed juices such as pomegranates and blueberries: First, different polyphenols play complementary roles against specific free radicals, such as ellagic acid in pomegranates to remove hydroxyl radicals, and anthocyanins in blueberries to remove superoxide anion radicals, and the mixture covers a wider range of free radical removal; on this basis, polyphenols promote each other through electron transfer or hydrogen atom transfer mechanisms, such as strawberry catechins provide hydrogen atoms to stabilize free radicals, and blueberry anthocyanins disperse free radical electrons through a conjugated system, synergistically improving the removal efficiency by more than 40%. Secondly, polyphenols combine chelated iron, copper and other metal ions, such as broccoli quercetin and purple cabbage anthocyanins bind Fe2+ and Cu2+, respectively, blocking the Fenton reaction chain, and the metal ion binding capacity of mixed juice is 25%-30% higher than that of single juice. Further, polyphenols form a multi-pathway defense system by activating antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). In addition, polyphenols are embedded in the lipid layer of cell membranes to inhibit lipid peroxidation (for example, blueberry anthocyanins and pomegranate ellagic acid synergize to inhibit MDA by 78%), while repairing oxidatively damaged DNA (for example, broccoli and purple cabbage metabolites activate the DNA repair enzyme OGG1). Ultimately, the total antioxidant capacity (ORAC value) of mixed juices can reach 1.8-2.3 times that of a single juice, reflecting the synergistic network effect of polyphenols in molecular complementarity, metabolic regulation and physical protection.

[0042] 2. The functionalized complex provided by the present invention not only has a clarification function (magnetic nanoparticles), but can also be reused for magnetic separation, and can fully extract polyphenols, improve enzymatic hydrolysis efficiency, and protect the stability and biological activity of polyphenols. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Unless otherwise specified, the reagents and raw materials used in the present invention are commercially available.

[0045] Nano-iron tetroxide, with an average particle size of 50 nm, was purchased from Shanghai Xianxin New Material Technology Co., Ltd.

[0046] Xylanase, model BR-M1081, was purchased from Shanghai Jining Biological Research Co., Ltd.

[0047] Example 1

[0048] This embodiment provides a method for preparing an antioxidant nutritious juice, comprising the following steps:

[0049] Preparation of functionalized composites:

[0050] A1, by weight, 1 part of nano-ferrosoferric oxide with an average particle size of 50 nanometers, 6 parts of 3-aminopropyltriethoxysilane, 40 parts of water, and 40 parts of ethanol were mixed and reacted at 50° C. for 6 hours under a nitrogen atmosphere, and the product was collected by magnetic separation to obtain a functionalized magnetic carrier;

[0051] A2, by weight, 4.2 parts of p-toluenesulfonyl chloride, 10 parts of β-cyclodextrin and 70 parts of water were mixed, the pH was adjusted to 11 and the reaction temperature was 25°C for 3 hours to obtain mono-toluenesulfonated β-cyclodextrin;

[0052] A3, by weight, 3 parts of functionalized magnetic carrier, 1 part of mono-toluenesulfonated β-cyclodextrin and 70 parts of dimethylformamide were mixed and reacted at 70°C for 12 h under a nitrogen atmosphere, and the nanocarrier was obtained after magnetic separation;

[0053] A4, by weight, 1 part of the nanocarrier, 75 parts of phosphate buffer with a pH of 7, and 7 parts of xylanase were mixed and shaken for loading, and then magnetically separated and washed to obtain a functionalized complex.

[0054] Preparation of antioxidant nutritious juice:

[0055] S1, by weight, crush the pulp of 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot, and add 0.2 parts of functionalized complex to perform enzymatic hydrolysis for 2 hours, and after the enzymatic hydrolysis, inactivate the enzyme at 85°C for 5 minutes, and remove the functionalized complex by magnetic separation to obtain pretreated juice;

[0056] S2, filtering the pretreated juice using a 200-mesh double-layer filter cloth, and then degassing to obtain an antioxidant nutritious juice.

[0057] Example 2

[0058] This embodiment provides a method for preparing an antioxidant nutritious juice, comprising the following steps:

[0059] Preparation of functionalized composites:

[0060] A1, by weight, 1 part of nano-ferrosoferric oxide with an average particle size of 50 nanometers, 8 parts of 3-aminopropyltriethoxysilane, 40 parts of water, and 40 parts of ethanol were mixed and reacted at 50° C. for 6 hours under a nitrogen atmosphere, and the product was collected by magnetic separation to obtain a functionalized magnetic carrier;

[0061] A2, by weight, 6.2 parts of p-toluenesulfonyl chloride, 10 parts of β-cyclodextrin and 70 parts of water were mixed, the pH was adjusted to 11 and the reaction temperature was 25°C for 3 hours to obtain mono-toluenesulfonated β-cyclodextrin;

[0062] A3, by weight, 5 parts of functionalized magnetic carrier, 1 part of mono-toluenesulfonated β-cyclodextrin and 70 parts of dimethylformamide were mixed and reacted at 70°C for 12 h under a nitrogen atmosphere, and the nanocarrier was obtained after magnetic separation;

[0063] A4, by weight, 1 part of the nanocarrier, 75 parts of phosphate buffer with a pH of 7, and 7 parts of xylanase were mixed and shaken for loading, and then magnetically separated and washed to obtain a functionalized complex.

[0064] Preparation of antioxidant nutritious juice:

[0065] S1, by weight, crush the pulp of 1 part of pomegranate, 2 parts of blueberry, 3 parts of strawberry, 3 parts of cherry, 4 parts of broccoli, 4 parts of purple cabbage, and 5 parts of carrot, and add 0.3 parts of functionalized complex to perform enzymatic hydrolysis for 2 hours, and after the enzymatic hydrolysis, inactivate the enzyme at 85°C for 5 minutes, and remove the functionalized complex by magnetic separation to obtain pretreated juice;

[0066] S2, filtering the pretreated juice using a 200-mesh double-layer filter cloth, and then degassing to obtain an antioxidant nutritious juice.

[0067] Comparative Example 1

[0068] The difference between this comparative example and Example 1 is that pomegranate is not added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot are changed to 1.17 parts of blueberry, 2.17 parts of strawberry, 1.17 parts of cherry, 2.17 parts of broccoli, 3.17 parts of purple cabbage, and 4.17 parts of carrot.

[0069] Comparative Example 2

[0070] The difference between this comparative example and Example 1 is that no blueberry is added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot are changed to 1.17 parts of pomegranate, 2.17 parts of strawberry, 1.17 parts of cherry, 2.17 parts of broccoli, 3.17 parts of purple cabbage, and 4.17 parts of carrot.

[0071] Comparative Example 3

[0072] The difference between this comparative example and Example 1 is that no strawberry is added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot are changed to 1.33 parts of pomegranate, 1.33 parts of blueberry, 1.33 parts of cherry, 2.33 parts of broccoli, 3.33 parts of purple cabbage, and 4.33 parts of carrot.

[0073] Comparative Example 4

[0074] The difference between this comparative example and Example 1 is that cherry is not added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot are changed to 1.17 parts of pomegranate, 1.17 parts of blueberry, 2.17 parts of strawberry, 2.17 parts of broccoli, 3.17 parts of purple cabbage, and 4.17 parts of carrot.

[0075] Comparative Example 5

[0076] The difference between this comparative example and Example 1 is that broccoli is not added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot are changed to 1.33 parts of pomegranate, 1.33 parts of blueberry, 2.33 parts of strawberry, 1.33 parts of cherry, 3.33 parts of purple cabbage, and 4.33 parts of carrot.

[0077] Comparative Example 6

[0078] The difference between this comparative example and Example 1 is that purple cabbage is not added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrot are changed to 1.5 parts of pomegranate, 1.5 parts of blueberry, 2.5 parts of strawberry, 1.5 parts of cherry, 2.5 parts of broccoli, and 4.5 parts of carrot.

[0079] Comparative Example 7

[0080] The difference between this comparative example and Example 1 is that carrots are not added, and 1 part of pomegranate, 1 part of blueberry, 2 parts of strawberry, 1 part of cherry, 2 parts of broccoli, 3 parts of purple cabbage, and 4 parts of carrots are changed to 2.33 parts of pomegranate, 2.33 parts of blueberry, 3.33 parts of strawberry, 2.33 parts of cherry, 3.33 parts of broccoli, and 4.33 parts of purple cabbage.

[0081] Comparative Example 8

[0082] The difference between this comparative example and Example 1 is that the functionalized complex in step S2 is replaced by xylanase.

[0083] Comparative Example 9

[0084] The difference between this comparative example and Example 1 is that the functionalized complex in step S2 is replaced by the nanocarrier in step A3.

[0085] Performance Testing

[0086] The fruit juices obtained in the examples and comparative examples were tested for antioxidant activity, and the results are shown in Table 1.

[0087] Table 1 Performance test results

[0088]

[0089]

[0090] From the above performance test results, it can be seen that the antioxidant properties of the juices obtained in Examples 1-2 are the best, especially the comprehensive performance of Example 2 is the most outstanding, which is mainly due to the synergistic mechanism between various fruits and vegetables and the extraction and utilization of polyphenols by the functional complex.

[0091] The comparative example does not adopt the necessary technical solution, resulting in its performance being significantly worse than that of the embodiment in the corresponding performance test. This better proves the irreplaceable nature of the specific technical solution of the present application in achieving technical effects and solving technical problems.

[0092] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing an antioxidant nutritious juice, characterized in that: The following steps are involved: S1, crushing the pulp of pomegranate, blueberry, strawberry, cherry, broccoli, purple cabbage and carrot, adding the functionalized complex for enzymatic hydrolysis, and then inactivating the enzyme after the enzymatic hydrolysis to obtain pretreated juice; S2, filtering the pretreated juice, and then degassing to obtain antioxidant nutritious juice.

2. The method for preparing the antioxidant nutritious juice according to claim 1, characterized in that: In step S1, the method for preparing the functionalized composite comprises the following steps: A1, mixing nano-ferroferric oxide, 3-aminopropyltriethoxysilane and a solvent for reaction, and collecting the product by magnetic separation to obtain a functional magnetic carrier; A2, mixing p-toluenesulfonyl chloride, β-cyclodextrin and water, adjusting the pH to 10-12 and reacting to obtain mono-toluenesulfonated β-cyclodextrin; A3, mixing the functionalized magnetic carrier, mono-toluenesulfonated β-cyclodextrin and dimethylformamide for reaction, and obtaining the nanocarrier after magnetic separation; A4, the nanocarrier, phosphate buffer and xylanase are mixed and shaken for loading, and then magnetically separated and washed to obtain a functionalized complex.

3. The method for preparing the antioxidant nutritious juice according to claim 2, characterized in that: In step A1, the particle size of the nano-iron tetroxide is 50-100 nm; And / or, in step A1, the mass ratio of the nano-ferroferric oxide, 3-aminopropyltriethoxysilane and the solvent is 1:(5-10):(50-100); And / or, in step A1, the solvent is a mixture of ethanol and water in a mass ratio of 1:1; And / or, in step A1, the reaction conditions are: under nitrogen atmosphere, at 40-70° C. for 4-8 hours.

4. The method for preparing the antioxidant nutritious juice according to claim 2, characterized in that: In step A2, the mass ratio of p-toluenesulfonyl chloride, β-cyclodextrin and water is (3-8):10:(50-100); And / or, in step A2, the reaction conditions are: reaction temperature is 20-30° C., and reaction time is 2-5 h.

5. The method for preparing the antioxidant nutritious juice according to claim 2, characterized in that: In step A3, the mass ratio of the functionalized magnetic carrier, mono-toluenesulfonated β-cyclodextrin and dimethylformamide is (2-6):1:(50-100); And / or, in step A3, the reaction conditions are: under nitrogen atmosphere, at 60-90° C. for 10-18 h.

6. The method for preparing the antioxidant nutritious juice according to claim 2, characterized in that: In step A4, the mass ratio of the nanocarrier, phosphate buffer and xylanase is 1:(50-100):(5-10); And / or, in step A4, the pH of the phosphate buffer is 7.2; And / or, in step A4, the oscillation time is 12-24 hours.

7. The method for preparing the antioxidant nutritious juice according to claim 1, characterized in that: In step S1, the mass ratio of the pomegranate, blueberry, strawberry, cherry, broccoli, purple cabbage and carrot is 1:(1-3):(2-4):(1-3):(2-5):(3-5):(4-6).

8. The method for preparing the antioxidant nutritious juice according to claim 1, characterized in that: In step S1, the amount of the enzyme added is 1-2 parts relative to 100 parts by mass of the pomegranate, blueberry, strawberry, cherry, broccoli, purple cabbage, and carrot; And / or, in step S1, the enzymatic hydrolysis time is 1-4h.

9. The method for preparing the antioxidant nutritious juice according to claim 1, characterized in that: In step S2, filtering is performed using a 200-mesh double-layer filter cloth.

10. An antioxidant nutritious juice obtained by the method for preparing the antioxidant nutritious juice according to any one of claims 1 to 9.

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