Walnut protein beverage and preparation method thereof

Abstract

The invention relates to the technical field of preparation of fermented beverages, in particular to a walnut protein beverage and a preparation method thereof. The invention provides a walnut protein beverage. The walnut protein beverage is prepared from the following components in parts by mass: 60-80 parts of walnuts, 6-10 parts of a compound stabilizer, 1-2 parts of a fermentation inoculant and 3-5 parts of a fermentation accelerant. The walnut protein beverage prepared by the method disclosed by the invention is pure in walnut taste, milky white, fine and smooth in mouth feel, suitable and soft in fermentation flavor, sour, sweet and delicious, suitable for people of all ages to drink, and wide in application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of fermented beverage preparation, in particular to a walnut protein beverage and a preparation method thereof. Background Art

[0002] Walnut is a common nut. Its kernel is shaped like a brain, so it is also called "brain fruit" or "longevity fruit". It has a very high nutritional value. Walnut contains a large amount of unsaturated fatty acids, especially linolenic acid, which is very beneficial to heart health. Walnut is also rich in protein, fat, thiamine, niacin, calcium, phosphorus, iron, riboflavin, vitamin A, vitamin B1, vitamin B2, vitamin C, vitamin E and other nutrients. It has the effects of nourishing the kidney and yang, nourishing the lungs and moistening the intestines. However, walnut kernels also contain a large amount of fat, which causes walnut kernels to contain a lot of calories. Excessive consumption can easily cause getting angry and make people feel nauseous. In severe cases, it can also lead to increased cholesterol and obesity.

[0003] Walnut milk is a pure natural plant protein drink. The product uses high-quality walnut kernels and pure water as the main raw materials. It is refined using modern technology and scientific blending. It has a delicate taste and a special walnut rich aroma. It can be drunk cold or hot, and the hot drink has a stronger aroma. Regular drinking has a good health care effect on arteriosclerosis, hypertension, coronary heart disease and anti-aging for the elderly. Therefore, this product is a superior drink with health value. However, in the prior art, walnut milk contains more auxiliary materials and additives. Although this can improve the taste of walnut milk, it will cover up the aroma of the walnut kernel itself, and will also lead to higher sugar and fat content in walnut milk, which will not only make the taste of walnut milk sweet and greasy, but also easily cause health problems such as obesity and hyperlipidemia.

[0004] Therefore, how to reduce the use of auxiliary materials and additives in walnut milk and provide a walnut-flavored fermented milk with rich taste, nutrition and health is a problem that technicians in this field urgently need to solve. Summary of the invention

[0005] The object of the present invention is to provide a walnut protein beverage and a preparation method thereof.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides a walnut protein beverage, which is prepared from the following components in parts by weight: 60-80 parts of walnuts, 6-10 parts of a composite stabilizer, 1-2 parts of a fermentation bacterial agent, and 3-5 parts of a fermentation accelerator; the fermentation bacterial agent is: Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus, and Streptococcus salivarius.

[0008] Preferably, the volume ratio of Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius is 16-20:16-20:15-19:15-19:13-17:10-16:7-11.

[0009] Preferably, the bacterial content of Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius is 500-700 million / mL.

[0010] Preferably, the composite stabilizer is: citrus fiber, sodium carboxymethyl cellulose and sodium alginate, with a mass ratio of 5-9:5-9:10-16.

[0011] Preferably, the fermentation promoter is: L-threonine, L-ornithine, L-tryptophan, casein hydrolyzate and sucrose, and the mass ratio is 0.2-0.4: 0.5-0.9: 0.4-0.8: 5-9: 20-30.

[0012] The present invention also provides a method for preparing the walnut protein beverage, comprising the following steps:

[0013] (1) frying walnuts, peeling them to obtain walnut kernels, and mixing the walnut kernels with water to obtain walnut milk;

[0014] (2) mixing the walnut milk and the composite stabilizer and sterilizing them;

[0015] (3) mixing the sterilized walnut milk, the fermentation agent, and the fermentation accelerator for fermentation and maturation to obtain walnut fermentation puree;

[0016] (4) The fermented walnut pulp is mixed and sterilized to obtain a walnut protein beverage.

[0017] Preferably, the frying temperature in step (1) is 120-140° C. and the frying time is 25-35 min.

[0018] Preferably, the mass ratio of the walnut kernels to water in step (1) is 1:6-10.

[0019] Preferably, the fermentation time in step (3) is 14 to 20 hours, and the temperature is 38 to 42°C; the maturation time is 20 to 26 hours, and the temperature is 1 to 3°C.

[0020] Preferably, the sterilization temperature in step (2) is 85-92°C and the time is 14-20 min; and the sterilization temperature in step (4) is 116-126°C and the time is 14-20 min.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The walnut protein beverage provided by the present invention not only enriches the drinking taste of the beverage by fermentation of probiotics, but also makes the beverage have good antioxidant effect. Among the probiotic strains added by the present invention, Lactobacillus helveticus and Lactobacillus acidophilus can decompose the crude protein in the fermentation system, Staphylococcus xylosus has the effect of decomposing the oil in the fermentation system to reduce the fat content in the fermentation system, Pediococcus pentosaceus plays an important role in the change of the flavor of the product fermentation process, and the addition of Streptococcus salivarius can also enrich the flavor components in the fermented milk. Lactobacillus bulgaricus and Lactobacillus casei can decompose lactose into lactic acid, thereby producing sour taste when fermenting dairy products. In addition, antibacterial substances can also be produced to resist the invasion of other harmful microorganisms. Therefore, the present invention, through the addition of the above probiotics, makes the fermented pulp have a good fermentation flavor, low fat and high protein, rich in probiotics, and has excellent antioxidant activity and health care effects.

[0023] The present invention adds a composite stabilizer before fermentation. The interaction between citrus fiber, sodium carboxymethyl cellulose and sodium alginate can ensure that the product is uniform and stable during storage at room temperature or high temperature, without stratification, water precipitation and precipitation, which greatly improves the stability of the beverage. At the same time, adding a fermentation promoter with a specific composition can promote the rapid fermentation of probiotics and improve the fermentation effect.

[0024] The walnut protein beverage prepared by the method of the invention has a pure walnut flavor, is milky white, has a delicate taste, has a mild fermented flavor, and is sweet and sour. It is suitable for people of all ages to drink and has broad application prospects. DETAILED DESCRIPTION

[0025] The present invention provides a walnut protein beverage, which is prepared by the following components in parts by mass: 60-80 parts of walnuts, 6-10 parts of a composite stabilizer, 1-2 parts of a fermentation agent, and 3-5 parts of a fermentation promoter; preferably, it is prepared by the following components in parts by mass: 64-76 parts of walnuts, 7-9 parts of a composite stabilizer, 1.5 parts of a fermentation agent, and 4 parts of a fermentation promoter; further preferably, it is prepared by the following components in parts by mass: 68-72 parts of walnuts, 8 parts of a composite stabilizer, 1.5 parts of a fermentation agent, and 4 parts of a fermentation promoter; more preferably, it is prepared by the following components in parts by mass: 70 parts of walnuts, 8 parts of a composite stabilizer, 1.5 parts of a fermentation agent, and 4 parts of a fermentation promoter.

[0026] In the present invention, the fermentation bacteria are: Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius.

[0027] In the present invention, the volume ratio of Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius is 16-20:16-20:15-19:15-19:13-17:10-16:7-11; preferably 17-19:17-19:16-18:16-18:14-16:11-15:8-10; further preferably 18:18:17:17:15:12-14:9; more preferably 18:18:17:17:15:13:9.

[0028] In the present invention, the bacterial content of Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius is 500-700 million / mL, preferably 600 million / mL.

[0029] In the present invention, the composite stabilizer is: citrus fiber, sodium carboxymethyl cellulose and sodium alginate, and the mass ratio is 5-9:5-9:10-16; preferably 6-8:6-8:11-15; more preferably 7:7:12-14; more preferably 7:7:13.

[0030] In the present invention, the fermentation promoter is: L-threonine, L-ornithine, L-tryptophan, casein hydrolyzate and sucrose, and the mass ratio is 0.2-0.4:0.5-0.9:0.4-0.8:5-9:20-30; preferably 0.3:0.6-0.8:0.5-0.7:6-8:22-28; further preferably 0.3:0.7:0.6:7:24-26; more preferably 0.3:0.7:0.6:7:25.

[0031] The present invention also provides a method for preparing the walnut protein beverage, comprising the following steps:

[0032] (1) frying walnuts, peeling them to obtain walnut kernels, and mixing the walnut kernels with water to obtain walnut milk;

[0033] (2) mixing the walnut milk and the composite stabilizer and sterilizing them;

[0034] (3) mixing the sterilized walnut milk, the fermentation agent, and the fermentation accelerator for fermentation and maturation to obtain walnut fermentation puree;

[0035] (4) The fermented walnut pulp is mixed and sterilized to obtain a walnut protein beverage.

[0036] In the present invention, the frying temperature in step (1) is 120-140°C and the time is 25-35 min; preferably, the frying temperature is 124-136°C and the time is 27-33 min; more preferably, the frying temperature is 128-132°C and the time is 29-31 min; more preferably, the frying temperature is 130°C and the time is 30 min.

[0037] In the present invention, the mass ratio of the walnut kernel to water in step (1) is 1:6-10; preferably 1:7-9; more preferably 1:8.

[0038] In the present invention, the fermentation time of step (3) is 14 to 20 hours, and the temperature is 38 to 42°C; preferably, the fermentation time is 15 to 19 hours, and the temperature is 39 to 41°C; more preferably, the fermentation time is 16 to 18 hours, and the temperature is 40°C; more preferably, the fermentation time is 17 hours, and the temperature is 40°C.

[0039] In the present invention, the ripening time in step (3) is 20 to 26 hours, and the temperature is 1 to 3°C; preferably, the ripening time is 21 to 25 hours, and the temperature is 2°C; more preferably, the ripening time is 22 to 24 hours, and the temperature is 2°C; more preferably, the ripening time is 23 hours, and the temperature is 2°C.

[0040] In the present invention, the sterilization temperature in step (2) is 85-92°C and the time is 14-20 min; preferably, the sterilization temperature is 86-91°C and the time is 15-19 min; further preferably, the sterilization temperature is 87-90°C and the time is 16-18 min; more preferably, the sterilization temperature is 88°C and the time is 17 min.

[0041] In the present invention, the sterilization temperature in step (4) is 116-126°C, and the time is 14-20 min; preferably 117-125°C, and the time is 15-19 min; more preferably 118-124°C, and the time is 16-18 min; more preferably 121°C, and the time is 17 min.

[0042] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0043] Example 1

[0044] The invention provides a walnut protein beverage, which is prepared from the following components in parts by mass: 60 parts of walnuts, 6 parts of a composite stabilizer, 1 part of a fermentation bacterial agent, and 3 parts of a fermentation accelerator; the fermentation bacterial agents are: Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus, and Streptococcus salivarius, with a volume ratio of 16:16:15:15:13:10:7; and the bacterial content is 500 million / mL.

[0045] The composite stabilizer is: citrus fiber, sodium carboxymethyl cellulose and sodium alginate, and the mass ratio is 5:5:10.

[0046] The fermentation promoter is: L-threonine, L-ornithine, L-tryptophan, casein hydrolyzate and sucrose, and the mass ratio is 0.2:0.5:0.4:5:20.

[0047] The preparation method of the walnut protein beverage comprises the following steps:

[0048] (1) Putting shelled walnuts into a pot and frying them at a temperature of 120° C. for 25 min, after frying, shelling and removing the innermost thin skin close to the kernel to obtain walnut kernels, and mixing the walnut kernels with water at a mass ratio of 1:6 to obtain walnut milk;

[0049] (2) mixing the walnut milk with a composite stabilizer, and then sterilizing at 85° C. for 14 minutes;

[0050] (3) mixing the sterilized walnut milk, the fermentation agent and the fermentation accelerator, and then fermenting at 38° C. for 14 h, and then aging at 1° C. for 20 h to obtain walnut fermentation puree;

[0051] (4) the fermented walnut puree is prepared by adding water twice the volume of the fermented walnut puree and 1.6% of white sugar by weight of the fermented walnut puree, and then homogenizing;

[0052] (5) The homogenized material is sterilized at 116° C. for 14 min to obtain a walnut protein beverage.

[0053] Example 2

[0054] The invention provides a walnut protein beverage, which is prepared from the following components in parts by mass: 80 parts of walnuts, 10 parts of a composite stabilizer, 2 parts of a fermentation bacterial agent, and 5 parts of a fermentation accelerator; the fermentation bacterial agent comprises: Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus, and Streptococcus salivarius, with a volume ratio of 20:20:19:19:17:16:11; and the bacterial content is 700 million / mL.

[0055] The composite stabilizer is: citrus fiber, sodium carboxymethyl cellulose and sodium alginate, and the mass ratio is 9:9:16.

[0056] The fermentation promoter is: L-threonine, L-ornithine, L-tryptophan, casein hydrolyzate and sucrose, and the mass ratio is 0.4:0.9:0.8:9:30.

[0057] The preparation method of the walnut protein beverage comprises the following steps:

[0058] (1) Putting shelled walnuts into a pot and frying them at a temperature of 140° C. for 35 min, after frying, shelling and removing the innermost thin skin close to the kernel to obtain walnut kernels, and mixing the walnut kernels with water at a mass ratio of 1:10 to obtain walnut milk;

[0059] (2) mixing the walnut milk with a composite stabilizer, and then sterilizing at 92° C. for 20 min;

[0060] (3) mixing the sterilized walnut milk, the fermentation agent and the fermentation accelerator, and then fermenting at 42° C. for 20 h, and then ripening at 3° C. for 26 h to obtain walnut fermentation puree;

[0061] (4) the fermented walnut puree is prepared by adding 3 times the volume of water of the fermented walnut puree and 2.2% of white sugar by weight of the fermented walnut puree, and then homogenizing;

[0062] (5) The homogenized material is sterilized at 126° C. for 20 min to obtain a walnut protein beverage.

[0063] Example 3

[0064] The invention provides a walnut protein beverage, which is prepared from the following components in parts by mass: 70 parts of walnuts, 8 parts of a composite stabilizer, 1.5 parts of a fermentation bacterial agent, and 4 parts of a fermentation accelerator; the fermentation bacterial agent comprises: Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus, and Streptococcus salivarius, with a volume ratio of 18:18:17:17:15:13:9; and the bacterial content is 600 million / mL.

[0065] The composite stabilizer is: citrus fiber, sodium carboxymethyl cellulose and sodium alginate, and the mass ratio is 7:7:13.

[0066] The fermentation promoter is: L-threonine, L-ornithine, L-tryptophan, casein hydrolysate and sucrose, and the mass ratio is 0.3:0.7:0.6:7:25.

[0067] The preparation method of the walnut protein beverage comprises the following steps:

[0068] (1) Putting shelled walnuts into a pot and frying them at a temperature of 130° C. for 30 min, removing the shells and the innermost thin skin close to the kernels to obtain walnut kernels, and homogenizing the walnut kernels with water at a mass ratio of 1:8 to obtain walnut milk;

[0069] (2) mixing the walnut milk with a composite stabilizer, and then sterilizing at 89° C. for 17 min;

[0070] (3) mixing the sterilized walnut milk, the fermentation agent and the fermentation promoter, and then fermenting at 10° C. for 17 h, and then ripening at 2° C. for 23 h to obtain walnut fermentation puree;

[0071] (4) the fermented walnut puree is prepared by adding water twice the volume of the fermented walnut puree and 2% of white sugar by weight of the fermented walnut puree, and then homogenizing;

[0072] (5) The homogenized material is sterilized at 121° C. for 17 min to obtain a walnut protein beverage.

[0073] Experimental Example 1

[0074] Sensory evaluation

[0075] A panel of 10 practitioners in food-related fields was selected to conduct sensory quality appraisal of the walnut protein beverage. The specific appraisal items included taste, smell, texture and overall acceptability. The sensory scoring criteria are shown in Table 1, and the average score is shown in Table 2.

[0076] Among them, the product obtained by the method of Example 3 was used as the experimental group.

[0077] Control group 1, other methods were the same as those in Example 3, except that the fermentation agent was replaced with equal amounts of Lactobacillus plantarum subsp., Pediococcus pentosaceus and Kluyveromyces marxensis in a volume ratio of 1:1:1; the number of bacteria in the Lactobacillus plantarum subsp. seed liquid was 2×10 8 cfu / ml, the bacterial count of Pediococcus pentosaceus seed solution was 2×10 8 cfu / ml, the bacterial count of Kluyveromyces marx seed solution was 2×10 6 cfu / ml (reference CN 201410477356.4).

[0078] Control group 2: other methods were the same as those in Example 3, except that Staphylococcus xylosus and Streptococcus salivarius were replaced by equal amounts of Lactobacillus plantarum subsp. and Lactococcus lactis.

[0079] Control group 3: other methods are the same as those of Example 3, except that the citrus fiber in the composite stabilizer is replaced by an equal amount of microcrystalline cellulose.

[0080] Control group 4: other methods are the same as those of Example 3, except that L-threonine, L-ornithine and L-tryptophan in the fermentation promoter are replaced by an equal amount of distilled water.

[0081] Control group 5: other methods are the same as those of Example 3, except that the casein hydrolysate in the fermentation accelerator is replaced by an equal amount of yeast extract.

[0082] Table 1 Sensory scoring criteria

[0083]

[0084] Table 2 Sensory score statistics

[0085]

[0086] It can be seen from the contents recorded in Table 2 that the walnut protein beverage provided by the present invention has excellent taste and quality, which is significantly better than other control groups.

[0087] It can be seen from the data of control groups 1 and 2 that only by using the fermentation bacteria agent of the present invention can a better fermentation effect be achieved. If the bacteria therein are partially or completely replaced, it will have a significant impact on the taste and quality of the beverage.

[0088] From the data of control groups 3 to 5, it can be seen that the selection of composite stabilizers and fermentation promoters is also very important. If the components are not selected appropriately, it will also have a significant impact on the taste and quality of the beverage.

[0089] Experimental Example 2

[0090] Efficacy verification

[0091] The experimental group, control group 1 and control group 2 are the same as experimental example 1. After preparing the walnut fermented puree in step (3), each experimental group mixed the walnut fermented puree with water at a volume ratio of 2:3, 4:1 and 5:0 to prepare walnut fermented puree with concentrations of 40%, 80% and 100%, respectively. Then, the antioxidant capacity of the product obtained in each experimental group was verified, and the average value was taken after three measurements. The results are shown in Tables 3 to 5.

[0092] Among them, the BOXBIO DPPH free radical scavenging ability test kit was used to test the DPPH free radical scavenging ability of the product.

[0093] The BOXBIO hydroxyl radical scavenging ability test kit was used to test the hydroxyl radical scavenging ability of the product.

[0094] The total antioxidant capacity of the product was tested using the BOXBIO total antioxidant capacity test kit.

[0095] Table 3 DPPH free radical scavenging ability

[0096] Group 40％ 80％ 100％ Experimental Group 13.6％ 34.2％ 36.5％ Control group 1 8.4％ 19.7％ 23.8％ Control group 2 11.0％ 28.2％ 31.3％

[0097] Table 4 Hydroxyl radical scavenging ability

[0098] Group 40％ 80％ 100％ Experimental Group 17.5％ 36.9％ 38.1％ Control group 1 7.3％ 23.1％ 25.6％ Control group 2 13.2％ 31.5％ 32.4％

[0099] Table 5 Total antioxidant capacity

[0100]

[0101]

[0102] It can be seen from the contents recorded in Tables 3 to 5 that with the increase of product concentration, the antioxidant capacity of the products in each test group is improved, and the antioxidant capacity of the experimental group products is the strongest, followed by control group 1 and control group 2. This shows that the walnut fermented puree prepared by the present invention has good antioxidant capacity, and if the fermentation strain is replaced in whole or in part, the antioxidant effect of the product will be significantly affected.

[0103] The above is only 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 principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A walnut protein beverage, characterized in that: The invention is prepared by comprising the following components in parts by weight: 60 to 80 parts of walnuts, 6 to 10 parts of a composite stabilizer, 1 to 2 parts of a fermentation bacterial agent, and 3 to 5 parts of a fermentation accelerator; the fermentation bacterial agent is: Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus, and Streptococcus salivarius.

2. A walnut protein beverage according to claim 1, characterized in that: The volume ratio of Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius is 16-20:16-20:15-19:15-19:13-17:10-16:7-11.

3. A walnut protein beverage according to claim 1 or 2, characterized in that: The bacterial contents of the Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus acidophilus, Pediococcus pentosaceus, Staphylococcus xylosus and Streptococcus salivarius are all 500-700 million / mL.

4. A walnut protein beverage according to claim 1, characterized in that: The composite stabilizer comprises citrus fiber, sodium carboxymethyl cellulose and sodium alginate, and the mass ratio thereof is 5-9:5-9:10-16.

5. A walnut protein beverage according to claim 1, characterized in that: The fermentation promoter is: L-threonine, L-ornithine, L-tryptophan, casein hydrolyzate and sucrose, and the mass ratio is 0.2-0.4: 0.5-0.9: 0.4-0.8: 5-9: 20-30.

6. The method for preparing a walnut protein beverage according to any one of claims 1 to 5, characterized in that: The steps include: (1) frying walnuts, peeling them to obtain walnut kernels, and mixing the walnut kernels with water to obtain walnut milk; (2) mixing the walnut milk and the composite stabilizer and sterilizing them; (3) mixing the sterilized walnut milk, the fermentation agent and the fermentation accelerator for fermentation and maturation to obtain walnut fermentation puree; (4) The fermented walnut pulp is mixed and sterilized to obtain a walnut protein beverage.

7. A walnut protein beverage according to claim 6, characterized in that: The frying temperature in step (1) is 120-140° C. and the frying time is 25-35 minutes.

8. A walnut protein beverage according to claim 6, characterized in that: The mass ratio of the walnut kernel to water in step (1) is 1:6-10.

9. A walnut protein beverage according to claim 6, characterized in that: The fermentation time of step (3) is 14 to 20 hours at a temperature of 38 to 42°C; the maturation time is 20 to 26 hours at a temperature of 1 to 3°C.

10. A walnut protein beverage according to claim 6, characterized in that: The sterilization temperature in step (2) is 85-92°C and the time is 14-20 minutes; the sterilization temperature in step (4) is 116-126°C and the time is 14-20 minutes.

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