NL2028093B1 - Method for preparing koumiss-based active lactic acid bacteria-fruit juice beverage - Google Patents

Abstract

The present disclosure provides a method for preparing a koumiss-based active lactic acid bacteria (LAB)-fruit juice beverage, and belongs to the technical field of agricultural product processing. Fruit juice, koumiss-based starter, amino acids, and sugar are used as raw materials, fermented, and blended to prepare the koumiss-based active LAB-fruit juice beverage. The product of the present disclosure contains a large number of active LAB. The total anthocyanin content, total phenol content, and antioxidant activity of the product increase the nutritional value of the beverage and the product functions as a regulator of intestinal flora and a promoter of digestion and absorption. During the fermentation of the fruit juice beverage of the present disclosure, there is no need to peel, active ingredients in the peel are utilized fully, and filtration is performed after the fermentation, meanwhile, amino acids are added to provide a nitrogen source, reducing sugar is added to increase a carbon source, by making full use of the diversity of microbial flora in the koumiss, the viable count of LAB of the product is more than 108 CFU°mL'1, the product has stable quality and is sour-sweet and tasty, with a delicate taste, the product can be stored at 4°C for more than a month.

Description

METHOD FOR PREPARING KOUMISS-BASED ACTIVE LACTIC ACID BACTERIA-FRUIT JUICE BEVERAGE

TECHNICAL FIELD The present disclosure belongs to the technical field of agricultural products processing, and specifically relates to a method for preparing a koumiss-based active lactic acid bacteria (LAB)-fruit juice beverage.

BACKGROUND IO Mare's milk is a thin, white and slightly bluish liquid, with very complex composition. Horse is the only monogastric animal among dairy animals. A plurality of physiological functions and biochemical processes during lactation physiological period thereof are different from those of cows, sheep and camels. Proteins, lactose, vitamins and minerals in mare's milk are richer than those in other animal milk; there are essential amino acids and fatty acids to the human body, and nutrients are easily absorbed and digested by the body. The composition of mare's milk is very close to human milk, with high lactose, low fat, appropriate calcium to phosphorus ratio, high content of polyunsaturated fatty acids, high content of whey protein and other nutritional characteristics; protein therein appears as a fine soft curd in the stomach, resulting in higher digestion and absorption rate. Koumiss is fermented from mare's milk. In the fermented koumiss, lactose content is substantially reduced, and the content of fat and protein has a little change; the formation of acids, alcohols and esters give the koumiss unique sensory quality. There is an extremely complex microbial system in koumiss milk. After long-term natural fermentation, lactic acid bacteria and yeasts have formed a relatively stable micro-ecological environment. The mutual promotion and restriction among bacteria species control the flavor characteristics, nutritional characteristics, medical and health care functions of the koumiss. It has been shown that the koumiss contains Lactobacillus helveticus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus paracasei and other predominant LAB, and the diversity of microorganisms contained in the koumiss has a great advantage in the preparation of fruit juice-LAB beverages. The preparation of koumiss-based LAB beverages has been reported, but these beverages are all based on the simple blending of koumiss and fruit juice without fermentation, which limits the use of beneficial ingredients in the fruit juice.

SUMMARY The present disclosure provides a method for preparing a koumiss-based active LAB- fruit juice beverage, making full use of the diversity of the koumiss milk microbial flora; the fermented LAB beverage has high activity, stable properties and good taste.

In the present disclosure, fruit juice, koumiss-based starter, amino acids, and sugar are used as raw materials, fermented, and blended to prepare the koumiss-based active LAB- fruit juice beverage; the product of the present disclosure contains a large number of active LAB, including Lactobacillus plantarum, Lactobacillus helveticus, Lactobacillus acidophilus, Lactobacillus casei, Lactococcus lactis, Lactobacillus delbrueckii subsp.

bularicus, and Lactobacillus kefiranofaciens. The total anthocyanin content, total phenol content, and antioxidant activity of the product increase the nutritional value of the beverage and the product functions as a regulator of intestinal flora and a promoter of digestion and absorption. During the fermentation of the fruit juice beverage, there is no need to peel and core, active ingredients in the peel are utilized fully, and filtration is performed after the fermentation; meanwhile, amino acids are added to provide a nitrogen source, reducing sugar is added to increase a carbon source; by making full use of the diversity of microbial flora in the koumiss, the viable count of LAB of the product is more than 103 CFU-mL™: the product has stable quality, does not need to add a stabilizer, and is clear, transparent, sour-sweet and tasty, with a delicate taste; the product can be stored at 4°C for more than a month.

The objective of the present disclosure is implemented by the following technical solution: Unless otherwise specified, percentages used in the present disclosure are all in percent by weight.

(1) Pulp is prepared as follows: washing fruit to be fermented, adding purified water, juicing, adjusting pH value to 7.0 with saturated sodium carbonate solution, pasteurizing juice, and setting aside, wherein the fruit and the purified water have a weight ratio of 1:10-20; (2) Koumiss-based active LAB-fruit juice beverage is prepared as follows: mixing the pulp prepared in step (1) well with koumiss-based starter, reducing sugar, and amino acids, fermenting at 37°C for 2-4 days, and filtering to remove pomace, to prepare a base fluid of the koumiss-based active LAB-fruit juice beverage; blending the base fluid with or without conventional doses of citric acid and honey, finally adding sterile water to the total volume of a finished product, filling, and refrigerating the finished product to obtain the koumiss-based active LAB-fruit juice beverage. The koumiss-based starter may be prepared as follows: inoculating koumiss containing various LBA into an MRS broth with an inoculum size of 1-2% by volume, culturing at 37°C for 24-36 h to prepare a primary bacterial suspension; inoculating 10% by volume of new primary bacterial suspension in an MRS broth, culturing at 37°C for 24-36 h, and curing to obtain a secondary bacterial suspension; inoculating 10% by volume of secondary bacterial suspension in the next level of MRS broth, and continuing culture under the same conditions, where a bacterial suspension obtained at each level is used as the koumiss-based starter. The koumiss may contain Lactobacillus helveticus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus acidophilus, and the koumiss and the pulp may have a weight ratio of 0.05-0.1:1. The amino acid may include one or more of glycine, serine, threonine, tyrosine, asparagine, and glutamine, and the amino acid and the pulp may have a weight ratio of

0.01-0.03:1. The reducing sugar may include one or more of glucose, sucrose, lactose, galactose, fructose, and arabinose, and the reducing sugar and the pulp may have a weight ratio of

0.05-0.1:1. The fruit may include, but not be limited to, grape, blueberry, strawberry, apple, pear, and waxberry. Compared with the prior art, the present disclosure has the following significant advantages:

1. The present disclosure adopts koumiss as a starter of the LAB beverage, making full use of the microbial diversity of the koumiss; the fermented LAB beverage has a high viable count, high nutrient content, and strong antioxidant activity.

2. Conventional protein is replaced with amino acids as a nitrogen source; the product does not need stabilizer, is also very stable, clear, and transparent, sour-sweet and tasty, with a delicate taste, the product can be stored at 4°C for more than a month.

3. For fermentation process adopted in the present disclosure, the fruit is treated without peeling and coring, various active ingredients in the fruit are utilized fully, and filtration is performed after fermentation. Thus, the active ingredients are substantially improved.

DETAILED DESCRIPTION The present disclosure will be further described with reference to the following examples, but the protection scope of the present disclosure is not limited thereto.

Koumiss used in the present disclosure is provided by the Microbiology Research Group, Faculty of Life Science and Technology, Kunming University of Science and Technology.

Example 1: Preparation of blueberry juice-LAB beverage (1) Pulp preparation: 200 g of blueberries were washed, mixed with 2,000 g of purified water, and juiced; the pH value was adjusted to 7.0 with saturated sodium carbonate solution; the juice was pasteurized and set aside.

(2) Preparation of koumiss-based starter: 1 mL of koumiss was inoculated into 100 mL of MRS broth sterilized at 120°C for 15 min, and cultured at 37°C for 24 h to prepare a primary bacterial suspension; 10 mL of primary bacterial suspension was inoculated into 100 mL of MRS broth sterilized at 120°C for 15 min, and cultured at 37°C for 24 h to obtain a koumiss-based starter.

(3) Preparation of koumiss-based active LAB-fruit juice beverage: 100 g of koumiss- based starter, 100 g of glucose, and 20 g of glycine were added to the pulp prepared in step (1), mixed well, fermented at 37°C for two days, and filtered to remove the pomace to prepare a base fluid of the koumiss-based active LAB-fruit juice beverage; finally, sterile water was added to the total volume (1 L) of a finished product, and the koumiss- based active LAB-fruit juice beverage was obtained.

(4) Sensory evaluation of blueberry juice-LAB beverage: The overall acceptance, smell, taste, and appearance of the sample were scored by sensory evaluation. The sensory evaluation team was composed of 10 food professionals. Each indicator was scored by the scaling method. The average score of the sensory evaluation team was used as a final score of the sample. The scoring standard is shown in Table 1.

(5) Performance measurement of blueberry juice-L AB beverage: Total acid was tested by acid-base titration with reference to GB/T 12456-2008; total phenol was tested by Folin-Ciocalteu colorimetry in GBT 8313-2008; pH value was measured by the potential difference method with reference to GB10468-1989; viable count was determined by the dilution plate counting method with reference to GB 478935-2010; DPPH radical scavenging activity was determined by related spectrophotometry. The results are shown in Table 2.

Example 2: Preparation of apple juice-LBA beverage (1) Pulp preparation: 200 g of apples were washed, mixed with 4,000 g of purified water, and juiced; the pH value was adjusted to 7.0 with saturated sodium carbonate solution; the juice was pasteurized and set aside. 5 (2) Preparation of koumiss-based starter: Same as that in Example 1. (3) Preparation of koumiss-based juice-active LAB beverage: 300 g of koumiss-based starter, 100 g of sucrose, 200 g of lactose, 28 g of serine, and 56 g of threonine were added to the pulp prepared in step (1), mixed well, fermented at 37°C for four days, and filtered to remove the pomace to prepare a base fluid of the koumiss-based active LAB- fruit juice beverage; finally, sterile water was added to the total volume (10 L) of a finished product, and the koumiss-based active LAB-fruit juice beverage was obtained. (4) Sensory evaluation of apple juice-L AB beverage: Same as that in Example 1. (5) Performance measurement of apple juice-LAB beverage: Same as that in Example

1. Example 3: Preparation of pear juice-LAB beverage (1) Pulp preparation: 200 g of pears were washed, mixed with 2,500 g of purified water, and juiced; the pH value was adjusted to 7.0 with saturated sodium carbonate solution; the juice was pasteurized and set aside. (2) Preparation of koumiss-based starter: Koumiss containing various LBA was inoculated into an MRS broth with an inoculum size of 1% by volume, cultured at 37°C for 30 h to prepare a primary bacterial suspension; 10% by volume of primary bacterial suspension was inoculated in an MRS broth, cultured at 37°C for 30 h, and cured to obtain a secondary bacterial suspension, 10% by volume of secondary bacterial suspension was inoculated in the next level of MRS broth, and cultured at 37°C for 30 hto obtain a koumiss-based starter. (3) Preparation of koumiss-based juice-active LAB beverage: 150 g of koumiss-based starter, 200 g of sucrose, 100 g of fructose, 40 g of tyrosine, and 40 g of asparagine were added to the pulp prepared in step (1), mixed well, fermented at 37°C for four days, and filtered to remove the pomace to prepare a base fluid of the koumiss-based active LAB- fruit juice beverage; finally, sterile water was added to the total volume (5 L) of a finished product, and the koumiss-based active LAB-fruit juice beverage was obtained. (4) Sensory evaluation of pear juice-LAB beverage: Same as that in Example 1. (5) Performance measurement of pear juice-LAB beverage: Same as that in Example 1.

Example 4: Preparation of grape juice-LAB beverage (1) Pulp preparation: 200 g of grapes were washed, mixed with 3,000 g of purified water, and juiced; the pH value was adjusted to 7.0 with saturated sodium carbonate solution; the juice was pasteurized and set aside.

(2) Preparation of koumiss-based starter: Same as that in Example 1.

(3) Preparation of koumiss-based juice-active LAB beverage: 300 g of koumiss-based starter, 200 g of glucose, 100 g of arabinose, 12 g of glycine, and 20 g of glutamine were added to the pulp prepared in step (1), mixed well, fermented at 37°C for three days, and filtered to remove the pomace to prepare a base fluid of the koumiss-based active LAB- fruit juice beverage; finally, sterile water was added to the total volume (7 L) of a finished product, and the koumiss-based active LAB-fruit juice beverage was obtained. (4) Sensory evaluation of grape juice-LAB beverage: Same as that in Example 1.

(5) Performance measurement of grape juice-LAB beverage: Same as that in Example

1.

Example 5: Preparation of waxberry juice-LAB beverage (1) Pulp preparation: 200 g of waxberries were washed, mixed with 4,000 g of purified water, and juiced; the pH value was adjusted to 7.0 with saturated sodium carbonate solution; the juice was pasteurized and set aside.

(2) Preparation of koumiss-based starter: Same as that in Example 1.

(3) Preparation of koumiss-based juice-active LAB beverage: 320 g of koumiss-based starter, 100 g of glucose, 200 g of sucrose, and 84 g of threonine were added to the pulp prepared in step (1), mixed well, fermented at 37°C for three days, and filtered to remove the pomace to prepare a base fluid of the koumiss-based active LAB-fruit juice beverage; finally, sterile water was added to the total volume (10 L) of a finished product, and the koumiss-based active LAB-fruit juice beverage was obtained.

(4) Sensory evaluation of waxberry juice-LAB beverage: Same as that in Example 1. (5) Performance measurement of waxberry juice-LAB beverage: Same as that in Example 1. Table 1 Sensory evaluation of koumiss-based active LAB-fruit juice beverages acceptance fragrance, and sourness. moderate/fermented lactic acid land non-layered sensory sweeteners and sourness, and pure taste experience

2 Significant increases in fruit flavor, [Having original apple|Transparent. faint/Plcasant fragrance, and soumess, moderatelaroma and light lactic{yellow. and non-{sensory sweeteners and sourness, and pure taste [acid aroma lavered experience 3 Significant increases in fruit flavor. [Flat aroma Transparent, faintiPleasant fragrance, and soumess, moderate vellow, and non-jsensory sweeteners and soumess, and pure taste layered experience 4 Significant increase in soumess, moderate/Having original grape|Transparent, deep red. [Pleasant sweeteners and soumess, and pure taste [aroma and light lacticland non-lavered SENSOry acid aroma experience Moderate sweeteners and sourness, and|Strong smell of{Transparent, red, and/Fair Sensory slight foreign flavor fermented lactic acid |non-lavered experience The fermentation of the koumiss-based active LAB-fruit juice beverage prepared by the method of the present disclosure has different effects on different fruits, and generally has a positive effect on juices with palatefullness and obvious sourness, such as 5 blueberries, apples, pears, and grapes, and but has a fair effect on waxberries. Table 2 Performance indices of koumiss-based active LAB-fruit juice beverages Example Total acid | Total phenol | pH Viable count | DPPH radical /(g/100 g) (mg/mL) (CFU/ml) scavenging activity (%)

0.85 (0.75) 1.12 (0.80) 3554.29) | 52109010) | 8462)

1.22 (0.36) 0.81 (0.62) 3.45 (3.78) | 7 x 10° (107) 79 (58)

1.25 (0.10) 0.67 (0.35) 3.60 (6.10) | 3 x 10 (107) 63 (38)

1.50 (0.91) 1.32 (1.03) 3.18 (3.90) | 5 x 10W (107) | 83 (64)

1.62 (0.95) 1.09 (0.95) 3.10 (3.85) | 10 (10%) 79 (64) The brackets in the table are the performance indices of the raw juice before fermentation Performance test results show that in the koumiss-based active LAB-fruit juice beverage prepared by the method of the present disclosure, the total acid and total phenol increase, the pH decreases, and the viable count reaches more than 10° CFU/mL; DPPH radical scavenging activity characterizing an ability of substance to scavenge reactive oxygen species is one of the typical indices for evaluate the antioxidant activity of fruit and vegetable juices. The DPPH radical scavenging activity of the LAD fruit juice prepared by the present disclosure has shown an increasing trend. These results indicate that the quality of the LAD fruit juice prepared by the present disclosure has been substantially improved.

Claims (7)

-8- Conclusions A method for preparing a fruit juice drink containing active lactic acid bacteria (LAB) based on cowmis, the method comprising the following steps: (1) pulping, washing fruits to be fermented, adding purified water, squeezing, adjusting pH to 7.0 with saturated sodium carbonate solution, pasteurizing juice, and setting aside, the fruit and purified water being in a weight ratio of 1:10-20; (2) preparation of fruit juice drink with active LAB based on kumis mixing well the pulp prepared in step (1) with starter based on kumis, reducing sugar and amino acids, fermenting at 37°C for 2 — 4 days and filtering to remove marc, to prepare a base fluid of the fruit juice drink with active LAB based on koemi, adding sterile water to the total volume of a finished product, filling and cooling the finished product to make the fruit juice drink with active LAB based on koemis. The method for preparing a fruit juice drink with active LAB based on cowmis according to claim 1, wherein citric acid and honey are added to the base fluid of the fruit juice drink with active LAB based on cowmis for mixing. The method for preparing a fruit juice drink with active LAB based on cowmist according to claim 1 or 2, wherein the cowmis-based starter is prepared as follows: inoculating cowmist containing different LBA in an inoculum size MRS broth from 1-2% by volume, culturing at 37°C for 24-36 h to prepare a primary bacterial suspension; inoculating 10% by volume of primary bacterial suspension in an MRS decoction, culturing at 37°C for 24-36 hours, and maturing to obtain a secondary bacterial suspension; inoculating 10% by volume of secondary bacterial suspension into the next level of MRS broth, and continuing to culture under the same conditions, obtaining a bacterial suspension at each level as the cowis-based starter -9- is used. The process for preparing a fruit juice drink with active LAB based on cowmist according to claim 1, wherein the cowmist starter contains Lactobacillus helveticus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus acidophilus, and the cowmist-based starter and the pulp contain a weight ratio of 0.05 — 0.1:1. The method for preparing a fruit juice drink with active LAB based on cowmis according to claim 1, wherein the amino acid is one or more of glycine, serine, threonine, tyrosine, asparagine and glutamine, and the amino acid and the pulp have a weight ratio of 0 .01 — 0.03:1. The process for preparing a fruit juice drink with active LAB based on cowmis according to claim 1, wherein the reducing sugar is one or more of glucose, sucrose, lactose, galactose, fructose and arabinose, and the reducing sugar and the pulp are in a weight ratio of 0.05 — 0.1:1. The method for preparing a fruit juice drink with active LAB based on kumis according to claim 1, wherein the fruit includes, but is not limited to, grape, blueberry, strawberry, apple, pear, and yang mei.