A method for preparing an antioxidant fruit juice

Abstract

The application belongs to the technical field of food, and discloses a preparation method of antioxidant fruit juice. The preparation method of the fruit juice comprises the following steps: (1) taking pulp, beating, adding a first composite enzyme, and performing first enzymolysis treatment to obtain a product; (2) freezing the product of step (1), then heating, adding a second composite enzyme, performing second enzymolysis treatment, colloid grinding, filtering, sterilizing, and obtaining the antioxidant fruit juice; the first composite enzyme comprises pectinase and endoglucanase; the temperature of the first enzymolysis treatment is 40-55 DEG C, and the treatment time is 20-30 minutes; the second composite enzyme comprises pectinase and glucose oxidase; the temperature of the second enzymolysis treatment is 40-45 DEG C, and the treatment time is 40-60 minutes. The fruit juice prepared by the method has good antioxidant stability, is not prone to browning, and has high contents of vitamin C and carotenoids.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of food, and particularly relates to a preparation method of antioxidant fruit juice. BACKGROUND

[0002] Different fruits have obvious differences in the content of nutritional ingredients, which also makes the market prices of different fruits vary greatly. The skin and flesh of yellow peaches are golden yellow to orange yellow, and the flesh is dense and tough. Yellow peaches are very nutritious, containing rich vitamin C and a large amount of dietary fiber, carotene, lycopene, lutein and trace elements (iron, calcium, etc.), and have both fresh eating and processing characteristics. Yellow peaches are popular in the domestic and foreign markets because they have the effects of benefiting qi and blood and generating body fluid. Yellow peaches have thin skin, soft and juicy flesh, high water content, and the ripening period is mostly concentrated in July-August. After being picked, yellow peaches mature rapidly and are prone to rot. Processing yellow peaches into fruit juice beverages not only helps to solve the problems of production, sales, transportation and storage during the fruit harvest season, but also can generate greater economic benefits.

[0003] However, during the production and processing of yellow peach juice beverages, browning problems are prone to occur due to the presence of polyphenol oxidase, oxygen, polyphenols and vitamin C. Browning not only affects the sensory of the juice product, but also causes the loss of nutritional substances, affects the shelf life of the product, and reduces the stability of the product. At present, the beverage industry generally uses the method of adding a large amount of antioxidants to inhibit oxidation, but excessive use of antioxidants may have adverse effects on human health.

[0004] Therefore, it is urgent to provide a safe antioxidant technology for producing yellow peach juice. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a preparation method of antioxidant fruit juice. The fruit juice preparation method of the present application does not involve the addition of antioxidants, and also enables the antioxidant components to be effectively released and stabilized during the processing of the fruit juice, thereby improving the antioxidant stability of the fruit juice and maintaining the rich application components. For example, the fruit juice is not prone to browning, and has high vitamin C and carotenoid content.

[0006] The present application proposes a preparation method of antioxidant fruit juice, comprising the following steps:

[0007] (1) taking the flesh, beating the pulp, adding a first composite enzyme, and performing a first enzymatic treatment to obtain a product;

[0008] (2) freezing the product of step (1), then warming it up, adding a second composite enzyme, performing a second enzymatic treatment, colloid milling, filtering, sterilizing, and obtaining the antioxidant fruit juice;

[0009] The first complex enzyme includes pectinase and endoglucanase.

[0010] The temperature of the first enzymatic treatment is 40-55℃, and the treatment time is 20-30 minutes.

[0011] The second complex enzyme includes pectinase and glucose oxidase.

[0012] The temperature of the second enzymatic treatment is 40-45℃, and the treatment time is 40-60 minutes.

[0013] Preferably, in step (1), the pulp is yellow peach pulp.

[0014] Preferably, in step (1), the mass of the first complex enzyme is 0.010-0.030% of the mass of the pulp, and further preferably 0.015-0.020%.

[0015] Preferably, in step (1), the mass ratio of pectinase to endoglucanase in the first complex enzyme is 1:(0.3-0.8), and further preferably 1:(0.5-0.7).

[0016] Preferably, in step (1), the freezing temperature is -4℃ to 4℃, and further preferably 0-1℃.

[0017] Preferably, in step (1), the freezing time is 1-8 hours, and further preferably 2-5 hours.

[0018] Preferably, in step (1), before beating, the pulp is first soaked in a mixed solution of D-sodium erythorbate and citric acid with a mass fraction of 0.04-0.1% for 30-50 minutes, then the pulp is taken out and washed with water.

[0019] Preferably, the mass ratio of D-sodium erythorbate to citric acid in the mixed solution of D-sodium erythorbate and citric acid is 1:(1-2), and further preferably 1:(1-1.5). Soaking in the mixed solution of D-sodium erythorbate and citric acid helps to improve the antioxidant effect of the juice.

[0020] Preferably, malic acid is further added to the mixed solution of D-sodium erythorbate and citric acid. Preferably, the mass ratio of malic acid to citric acid is 1:(0.5-2), and further preferably 1:(1-1.5). Further adding malic acid helps to further improve the content of vitamin C and carotenoids in the juice.

[0021] Preferably, in step (1), the temperature of the first enzymatic treatment is 48-50℃, and the treatment time is 25-30 minutes.

[0022] Preferably, in step (2), the temperature of the second enzymatic treatment is 43-45℃, and the treatment time is 50-60 minutes.

[0023] Preferably, in step (2), the mass of the second complex enzyme is 0.015-0.040% of the mass of the fruit pulp, and more preferably 0.020-0.025%.

[0024] Preferably, in step (2), the mass ratio of pectinase to glucose oxidase in the second complex enzyme is 1:(0.3-0.8), and more preferably 1:(0.5-0.7).

[0025] Preferably, in step (2), the filter mesh size is 100-200 mesh.

[0026] Preferably, in step (2), the sterilization is performed at 95-100℃.

[0027] Preferably, in step (2), after filtration, sodium carboxymethyl cellulose is added, and shearing is performed for 5-10 minutes, and fructose syrup, acidulant and sweetener are added.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] The fruit juice preparation method of the present application involves two enzymatic treatments, and through specific complex enzymes and enzymatic conditions, the final fruit juice has good antioxidant properties, high vitamin and carotenoid content, and is not prone to browning, and has good stability. The specific enzymatic conditions are as follows: the first complex enzyme includes pectinase and endoglucanase; the temperature of the first enzymatic treatment is 40-55℃, and the treatment time is 20-30 minutes; after the first enzymatic treatment by pectinase and endoglucanase, the temperature is lowered for freezing to ensure the stability of the antioxidant nutrients, and then the second enzymatic treatment is performed, the second complex enzyme includes pectinase and glucose oxidase; the temperature of the second enzymatic treatment is 40-45℃, and the treatment time is 40-60 minutes, further releasing the nutrients in the fruit pulp and maintaining their stability. Thus, the flavor and color of the fruit juice are maintained, and the shelf life of the product is extended. DETAILED DESCRIPTION

[0030] To make the skilled in the art more clearly understand the technical solutions of the present application, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection required by the present application.

[0031] The raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels, or can be obtained by known methods.

[0032] 1. Pre-treatment of yellow peach pulp

[0033] Screening of yellow peach pulp: 100 grams of yellow peach pulp of different maturity from different manufacturers were selected, thawed at room temperature, pulped, and the sensory flavor was evaluated.

[0034] Table 1: Variety flavor of yellow peach pulp

[0035]

[0036]

[0037] As can be seen from Table 1, the yellow peach pulp provided by Geli Put has a golden color, moderate hardness, high sweetness, and rich aroma, which meets the requirements of production and processing.

[0038] 2. Selection of thawing method for yellow peach pulp: Take one piece (10 kg) of yellow peach pulp, and thaw it using different thawing methods. Compare and analyze the differences in color, juice loss rate, vitamin C content, and soluble solids content of yellow peach pulp under five thawing methods: low-temperature air thawing (environmental temperature 4℃), room temperature air thawing (room temperature 25℃), running water thawing (water temperature 24℃), warm water thawing (water temperature 50℃), and microwave thawing (thawing mode), and select the appropriate thawing method.

[0039] Table 2: Selection of thawing method for yellow peach pulp

[0040]

[0041] As can be seen from Table 1, running water thawing has the advantages of short thawing time, low juice loss rate, and low vitamin loss rate, which is beneficial to maintaining the quality of yellow peach pulp and is the best thawing method.

[0042] The yellow peach pulp used in the following examples and comparative examples is eight mature yellow peach pulp provided by Geli Put, which is thawed by running water thawing.

[0043] Example 1

[0044] An antioxidant fruit juice preparation method, comprising the following steps:

[0045] (1) Take 1 kg of yellow peach pulp, pulping, add the first composite enzyme, and perform the first enzymatic hydrolysis treatment to obtain a product;

[0046] (2) Freeze the product of step (1) at a temperature of 0℃ for 2 hours, then warm up to 45℃, add the second composite enzyme, and perform the second enzymatic hydrolysis treatment, then pass through a 100 mesh filter, and sterilize at 95℃ for 20 minutes to obtain an antioxidant fruit juice;

[0047] The first complex enzyme includes pectinase and endoglucanase, and the mass ratio of the pectinase to the endoglucanase is 1:0.5;

[0048] The temperature of the first enzymolysis treatment is 50°C, and the treatment time is 25 minutes;

[0049] The mass of the first complex enzyme is 0.020% of the mass of the yellow peach pulp;

[0050] The second complex enzyme includes pectinase and glucose oxidase, and the mass ratio of the pectinase to the glucose oxidase is 1:0.5;

[0051] The temperature of the second enzymolysis treatment is 45°C, and the treatment time is 50 minutes;

[0052] The mass of the second complex enzyme is 0.025% of the mass of the pulp.

[0053] Example 2

[0054] An antioxidant fruit juice preparation method, comprising the following steps:

[0055] (1) Take 1 kg of yellow peach pulp, soak the yellow peach pulp in a mixed solution of D-sodium isoascorbic acid and citric acid with a mass fraction of 0.05%, soak for 50 minutes, then take out the yellow peach pulp, wash it with water for 5 times, the mixed solution of D-sodium isoascorbic acid and citric acid, and the mass ratio of D-sodium isoascorbic acid to citric acid is 1:1, then pulp, add a first complex enzyme, and perform a first enzymolysis treatment to obtain a product;

[0056] (2) Freeze the product of step (1), the freezing temperature is 0°C, the freezing time is 2 hours, then warm up to 45°C, then add a second complex enzyme, perform a second enzymolysis treatment, cycle colloid mill for 2 minutes, filter through a 100 mesh screen, sterilize at 95°C for 20 minutes, and obtain an antioxidant fruit juice;

[0057] The first complex enzyme includes pectinase and endoglucanase, and the mass ratio of the pectinase to the endoglucanase is 1:0.5;

[0058] The temperature of the first enzymolysis treatment is 50°C, and the treatment time is 25 minutes;

[0059] The mass of the first complex enzyme is 0.020% of the mass of the yellow peach pulp;

[0060] The second complex enzyme includes pectinase and glucose oxidase, and the mass ratio of the pectinase to the glucose oxidase is 1:0.5;

[0061] The temperature of the second enzymolysis treatment is 45°C, and the treatment time is 50 minutes;

[0062] The mass of the second complex enzyme is 0.025% of the mass of the pulp.

[0063] Example 3

[0064] An antioxidant fruit juice preparation method, comprising the following steps:

[0065] (1) Take 1 kg of yellow peach pulp, soak the yellow peach pulp in a mixed solution of sodium D-erythorbate and citric acid and malic acid with a mass fraction of 0.05%, soak for 50 minutes, then take out the yellow peach pulp, wash it with water 5 times, the mass ratio of sodium D-erythorbate to citric acid and malic acid in the mixed solution of sodium D-erythorbate and citric acid is 1:1:1, then pulp, add the first complex enzyme, and perform the first enzymatic treatment to obtain a product;

[0066] (2) Freeze the product of step (1), the freezing temperature is 0℃, the freezing time is 2 hours, then warm up to 45℃, then add the second complex enzyme, and perform the second enzymatic treatment, colloid mill for 2 minutes, filter through a 100 mesh screen, sterilize at 95℃ for 20 minutes, to obtain an antioxidant fruit juice;

[0067] The first complex enzyme comprises pectinase and endoglucanase, and the mass ratio of pectinase to endoglucanase is 1:0.5;

[0068] The temperature of the first enzymatic treatment is 50℃, and the treatment time is 25 minutes;

[0069] The mass of the first complex enzyme is 0.020% of the mass of the yellow peach pulp;

[0070] The second complex enzyme comprises pectinase and glucose oxidase, and the mass ratio of pectinase to glucose oxidase is 1:0.5;

[0071] The temperature of the second enzymatic treatment is 45℃, and the treatment time is 50 minutes;

[0072] The mass of the second complex enzyme is 0.025% of the mass of the pulp.

[0073] Comparative Example 1

[0074] Comparative Example 1 differs from Example 1 only in that an equal amount of glucose oxidase is used instead of endoglucanase, and the rest of the process is the same as Example 1.

[0075] Comparative Example 2

[0076] Comparative Example 2 differs from Example 1 only in that it is placed at room temperature for 2 hours instead of the freezing process, and the rest of the process is the same as Example 1.

[0077] Comparative Example 3

[0078] Comparative Example 3 differs from Example 1 only in that the first enzymatic treatment and freezing are not performed, and the rest of the process is the same as Example 1. That is, Comparative Example 3 is performed with only one enzymatic treatment.

[0079] Comparative Example 4

[0080] Comparative Example 4 differs from Example 1 only in that the temperature of the first enzymatic treatment is 38°C and the treatment time is 25 minutes; the temperature of the second enzymatic treatment is 50°C and the treatment time is 50 minutes, and the rest of the process is the same as Example 1.

[0081] Product Effect Test

[0082] The fruit juice prepared in the above examples and comparative examples was tested for vitamin C and carotenoid content according to a conventional method, and the results are shown in Table 3.

[0083] Table 3

[0084]

[0085] As can be seen from Table 3, the vitamin C and carotenoid content of the fruit juice prepared in the examples of the present application is significantly higher than that of Comparative Examples 1-4. It can also be seen that the two enzymatic treatments and the freezing process in the fruit juice preparation method of the present application have a significant effect on the vitamin C and carotenoid content of the fruit juice.

Claims

1. A method for preparing antioxidant juice, characterized in that: The following steps are involved: (1) taking the pulp, beating it, adding a first complex enzyme, and performing a first enzymatic hydrolysis treatment to obtain a product; (2) freezing the product of step (1), then heating it, adding a second complex enzyme, performing a second enzymatic hydrolysis treatment, grinding, filtering, and sterilizing to obtain the antioxidant juice; The first complex enzyme comprises pectinase and endoglucanase; the mass of the first complex enzyme is 0.010-0.030% of the mass of the pulp; The temperature of the first enzymatic hydrolysis treatment is 40-55°C, and the treatment time is 20-30 minutes; The second complex enzyme comprises pectinase and glucose oxidase; the mass of the second complex enzyme is 0.015-0.040% of the mass of the pulp; The temperature of the second enzymatic hydrolysis treatment is 40-45° C., and the treatment time is 40-60 minutes.

2. The method for preparing juice according to claim 1, characterized in that: In step (1), the pulp is yellow peach pulp; and / or the mass of the first complex enzyme is 0.015-0.020% of the mass of the pulp.

3. The method for preparing juice according to claim 1, characterized in that: In step (1), the mass ratio of pectinase to endoglucanase in the first complex enzyme is 1:(0.3-0.8).

4. The method for preparing juice according to claim 1, characterized in that: In step (1), the freezing temperature is -4°C to 4°C.

5. The method for preparing juice according to claim 4, characterized in that: In step (1), the freezing time is 1-8 hours.

6. The method for preparing juice according to any one of claims 1 to 5, characterized in that: In step (1), before beating, the pulp is first soaked in a mixed solution of sodium D-isoascorbate and citric acid with a mass fraction of 0.04-0.1% for 30-50 minutes, and then the pulp is taken out and washed with water.

7. The method for preparing juice according to claim 6, characterized in that: In the mixed solution of sodium D-isoascorbate and citric acid, the mass ratio of sodium D-isoascorbate to citric acid is 1:(1-2).

8. The method for preparing juice according to claim 6, characterized in that: Malic acid is also added to the mixed solution of sodium D-isoascorbate and citric acid.

9. The method for preparing juice according to claim 1, characterized in that: The mass of the second complex enzyme is 0.020-0.025% of the mass of the pulp.

10. The method for preparing juice according to claim 1, characterized in that: In step (2), the mass ratio of pectinase to glucose oxidase in the second complex enzyme is 1:(0.3-0.8); and / or, in step (2), the sterilization is carried out at 95-100°C.

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