CN116268089B - Flavored fermented milk containing hyaluronic acid and preparation method thereof - Google Patents

Abstract

The invention discloses a flavored fermented milk containing hyaluronic acid and a preparation method thereof, wherein the flavored fermented milk comprises the following raw materials in parts by weight: 750-950 parts of raw milk, 3-15 parts of stabilizer, 3-9 parts of compound hyaluronic acid or salt thereof, 0.02-0.1 part of starter and 5-30 parts of prebiotics. The flavored fermented milk disclosed by the invention is more uniform in color, smooth and smooth in surface, finer and softer in taste, smooth, mellow, free of astringency, free of stimulation in swallowing, good in sensory quality and more suitable for the current trend of consumers for pursuing functions and taste at the same time. The fermented milk has low whey precipitation rate, stable viscosity, stable consistency and stable lactobacillus number during storage, and long shelf life.

Description

Flavored fermented milk containing hyaluronic acid and preparation method thereof

Technical Field

The invention relates to a fermented milk and a preparation method thereof, and in particular to a flavored fermented milk having the functions of regulating the gastrointestinal tract and improving skin moisture, having a good taste, moderate viscosity, good storage stability, maintaining a stable number of beneficial bacteria, and a long shelf life, and belongs to the technical field of fermented milk products.

Background Art

Hyaluronic acid (HA) is a linear high molecular weight acidic mucopolysaccharide composed of D-glucuronic acid and N-acetylglucosamine disaccharide units. It is widely present in the interstitial cells of animal tissues and is a natural component of organisms. HA is most abundant in the dermis of human skin and synovial fluid. It has unique rheological properties, lubricity, viscoelasticity, and antibacterial properties. It is the best natural substance with the best water retention found in nature and is widely used in food, daily chemicals, and medicine. After oral administration, HA has the functions of moisturizing, anti-oxidation, improving joint function and osteoporosis, repairing gastric mucosal damage, and relieving dry eyes. Oral HA is mild, long-lasting, safer and more stable, and therefore is increasingly favored by consumers.

Flavored fermented milk is a dairy product obtained by sterilizing and fermenting more than 80% raw cow (sheep) milk or milk powder, adding other raw materials, and adding food additives, nutritional enhancers, fruits, vegetables, grains and other ingredients before or after fermentation to increase the taste or efficacy of fermented milk. Fermented milk is loved by consumers for its sweet and sour flavor and rich nutritional value. However, as people's expectations for health continue to increase and they are more and more anxious about health, traditional fermented milk is gradually less attractive to consumers and cannot meet consumers' needs for healthy diet. Therefore, functional flavored fermented milk has gradually come into people's view. In addition, with the promotion of sugar-reduced life, flavored fermented milk containing natural sweeteners without adding sucrose has gradually become popular.

At present, the following problems are common in flavored fermented milk on the market: fermented milk has a single function and cannot meet the diverse functional needs of consumers; the functional ingredients added to functional fermented milk such as DHA algae oil flavored fermented milk contain unpleasant odors, which are not acceptable to consumers; most flavored fermented milks are prepared with white sugar, which is high in calories and does not conform to the current trend of low-sugar diets; in order to achieve the required viscosity, many types of thickeners are used or the amount is large; the fermented milk tastes not delicate and soft, has astringent taste, and is slightly irritating when swallowed; the lactic acid in fermented milk can irritate people with damaged gastric mucosa and cause gastric acid. In addition, flavored fermented milk often has the following product quality problems to varying degrees during the fermentation and storage process: dehydration and shrinkage, accompanied by the occurrence of whey precipitation and other phenomena; the number of beneficial bacteria decreases, affecting the function of fermented milk; and viscosity decreases. This series of problems will seriously affect the stability of the system and the taste and quality of the product, affect its shelf life, and reduce the consumer experience.

Patent CN103349072B discloses a soy protein isolate emulsified vegetable oil type health yogurt and a method for making it. The method adds hyaluronic acid, increases skin elasticity, and can maintain the plumpness of the skin before and after weight loss; increases the proportion of soy protein, improves the lubricity of yogurt, and can achieve a good coagulation effect without adding stabilizers and thickeners. However, soy protein isolate has an unacceptable odor, which affects the flavor of yogurt, and the sweetener used also contains sucrose, which does not conform to the current trend of low-sugar diet. In addition, the absence of stabilizers and thickeners will easily cause syneresis and whey precipitation during subsequent storage, thereby affecting the stability and taste of yogurt.

Therefore, it is necessary to develop a flavored fermented milk with multiple functions, suitable for people with damaged gastric mucosa, free of peculiar smell, low in sugar or sugar-free, with a soft and smooth taste without astringency, no syneresis and whey precipitation during storage, stable viscosity and number of beneficial bacteria, and extended shelf life.

Summary of the invention

In view of the problems that the existing fermented milk products are easy to precipitate whey during storage, the viscosity and the number of beneficial bacteria are easy to decrease during storage, the efficacy is single, and it is not suitable for people with damaged gastric mucosa, the present invention provides a flavored fermented milk containing hyaluronic acid. The flavored fermented milk of the present invention has the effects of regulating the stomach and skin care through the selection and matching of ingredients, and has good taste, unique flavor, no odor, suitable viscosity, and does not use white sugar, which conforms to the trend of low-sugar diet, and is particularly suitable for beauty and skin care, gastric mucosal damage, and weight loss. The present invention improves the stability of flavored fermented milk by matching composite hyaluronic acid or its salt with a stabilizer, reduces the phenomenon of whey precipitation during storage, improves the retention of viscosity and the number of beneficial bacteria during storage, and extends its shelf life, and has a good market prospect.

The specific technical solutions of the present invention are as follows:

A flavored fermented milk containing hyaluronic acid comprises the following raw materials in parts by weight: 750-950 parts of raw cow milk, 3-15 parts of a stabilizer, 3-9 parts of a composite hyaluronic acid or a salt thereof, 0.02-0.1 parts of a starter, and 5-30 parts of a prebiotic.

Furthermore, the flavored fermented milk also includes a flavor regulator, the main function of which is to adjust the overall taste of the flavored fermented milk to formulate a flavor that is more easily accepted by the human body. The flavor regulator can be at least one of skim milk powder, whey protein powder and sweetener. In a specific embodiment of the present invention, the flavor regulator is 25 to 45 parts of skim milk powder, 8 to 15 parts of whey protein powder and 45 to 105 parts of sweetener.

Furthermore, other raw materials that enrich the taste and efficacy, such as nutritional enhancers, fruits and vegetables, and grains, may be added to the above-mentioned flavored fermented milk.

Furthermore, in the above-mentioned flavored fermented milk, the raw cow's milk is healthy, odorless, high in protein, and antibiotic-free, and meets the standard requirements of GB19301.

Furthermore, in the above-mentioned flavored fermented milk, the mass ratio of the skim milk powder to the whey protein powder is 1 to 8:1, preferably 2 to 5:1. Skim milk powder can adjust the texture and flavor of fermented milk, while reducing fat intake, and avoiding the occurrence of hyperlipidemia to a certain extent. Whey protein powder can increase viscosity, is easy to digest, has the advantages of high purity, high absorption rate, and the most reasonable amino acid composition, and can increase the protein content of fermented milk and improve its nutritional value.

Furthermore, in the above-mentioned flavored fermented milk, the composite hyaluronic acid or its salt is a composition of high molecular weight hyaluronic acid or its salt, medium molecular weight hyaluronic acid or its salt and low molecular weight hyaluronic acid or its salt. The compounding of these three hyaluronic acids or their salts with different molecular weights and their combination with a stabilizer have a better effect of increasing stability.

Furthermore, the molecular weight of the high molecular weight hyaluronic acid or its salt is 1.5×10 ⁶ Da to 2.5×10 ⁶ Da, the molecular weight of the medium molecular weight hyaluronic acid or its salt is 5×10 ⁵ Da to 1.4×10 ⁶ Da, and the molecular weight of the low molecular weight hyaluronic acid or its salt is 5×10 ³ Da to 4×10 ⁵ Da.

Preferably, when the mass ratio of high molecular weight hyaluronic acid or its salt, medium molecular weight hyaluronic acid or its salt and low molecular weight hyaluronic acid or its salt is 2:1.5-4:0.5-3, the obtained flavored fermented milk has better performance in various aspects.

Furthermore, the hyaluronate includes sodium salt, zinc salt, calcium salt, potassium salt and the like of hyaluronic acid.

Furthermore, the stabilizer is a mixture of guar gum and pectin. Compared with other similar types of stabilizers, this combination of stabilizers has a better stabilizing effect when combined with hyaluronic acid or its salt, can better improve the stability of the flavored fermented milk during storage, and can better maintain the viscosity of the flavored fermented milk and the number of beneficial bacteria.

Preferably, the mass ratio of guar gum to pectin is 5 to 15:1, more preferably 7 to 12:1.

Further, the sweetener is one or more of erythritol, xylitol, lactitol, mannitol, sorbitol, maltitol and isomalt. Compared with sucrose, these sweeteners have lower calories.

Further, the fermentation agent is thermophilic streptococcus, lactobacillus bulgaricus and bifidobacterium. The bifidobacterium can be one or more of bifidobacterium adolescentis, bifidobacterium lactis, bifidobacterium bifidum, bifidobacterium breve, bifidobacterium infantis and bifidobacterium longum. The type of fermentation agent used in the present invention can be selected according to the reports of the prior art, and these ingredients are all commercially available products.

Preferably, the mass ratio of the thermophilic Streptococcus, the bulgaricus Lactobacillus and the bifidobacterium is 4-9:1-3:1.

Furthermore, the prebiotics are small molecule oligosaccharides, which can be one or more of fructooligosaccharides, galacto-oligosaccharides, xylooligosaccharides, maltooligosaccharides and polydextrose. The prebiotics can increase the health care effect of the present invention and also improve the survival number of beneficial bacteria.

Furthermore, the present invention also provides a method for preparing flavored fermented milk containing hyaluronic acid, the method comprising the following steps:

(1) heating raw milk, adding skim milk powder and whey protein powder, and stirring evenly;

(2) taking 20-30 wt% of the mixture of step (1), adding a stabilizer after heating, and stirring evenly;

(3) taking the remaining mixture of step (1), cooling it, adding the composite hyaluronic acid or its salt, stirring it evenly, and then adding the sweetener and prebiotics, and stirring it evenly again;

(4) mixing the mixtures of steps (2) and (3) and performing two-stage homogenization;

(5) sterilizing the homogenized mixture, cooling it to the fermentation temperature, adding a starter and fermenting it at a constant temperature;

(6) The fermented product is cooled, filled, refrigerated, and matured to obtain flavored fermented milk containing hyaluronic acid.

Furthermore, in step (1), the raw milk is heated to 45-55° C. and skim milk powder and whey protein powder are added. After addition, the raw materials are fully stirred to mix them evenly, and the stirring time is generally 15-20 minutes.

Furthermore, in step (2), the temperature is raised to 60-70°C and the stabilizer is added. At this temperature, the mixing time of the stabilizer is shorter. After adding, the stabilizer is fully mixed under high-speed stirring, and the mixing time is generally 10-15 minutes.

Furthermore, in step (3), the temperature is lowered to 15-25° C., and composite hyaluronic acid or its salt is slowly added. Preferably, high molecular sodium hyaluronate, medium molecular sodium hyaluronate, and low molecular sodium hyaluronate are slowly added. The adding method is to slowly add high molecular sodium hyaluronate to the solution while stirring, gradually increase the stirring speed, and stir until it is completely dissolved; continue to slowly add medium molecular sodium hyaluronate and stir until it is completely dissolved; finally, add low molecular sodium hyaluronate, continue to stir for 15 to 20 minutes after addition, and then add sweeteners and prebiotics, continue to stir evenly, and the stirring time is generally 10 to 15 minutes.

Furthermore, in step (4), the temperature of the first stage homogenization is 55-75°C, preferably 60-70°C, and the homogenization pressure is 10-20Mpa. The temperature of the second stage homogenization is 55-75°C, preferably 60-70°C, and the homogenization pressure is 3-8Mpa.

Furthermore, in step (5), the fermentation temperature is 42-45°C, and the fermentation is performed until the acidity reaches 70-72°T, and the fermentation time is generally 4 to 10 hours.

Furthermore, in step (6), the fermented product is cooled to 13-15° C., filled and sealed under the prescribed hygiene requirements, and refrigerated at 0-6° C. for 12-24 hours to obtain a flavored fermented milk product containing hyaluronic acid.

The present invention has the following beneficial effects:

(1) The flavored fermented milk of the present invention is compounded with three kinds of hyaluronic acid or its salts of high, medium and low molecular weights, and the prebiotics are small molecular oligosaccharides. The molecules of high and medium molecular weight hyaluronic acid or its salts in the solution can interact with each other to form a network structure, thereby embedding the starter and the prebiotics therein, and the low molecular weight hyaluronic acid or its salts can form a protective layer with smaller meshes to cover the above-mentioned grid structure, thereby protecting the starter and enabling the starter to fully utilize the prebiotics for metabolism and proliferation, thereby stabilizing the number of live beneficial bacteria during storage. The addition of prebiotics plays a dual protective role on the number of live beneficial bacteria.

(2) The present invention adds composite hyaluronic acid or its salt to flavored fermented milk, and effective ingredients such as probiotics, prebiotics, fermentation agents, composite hyaluronic acid or its salt can play a synergistic role, which is beneficial to the gastrointestinal health of the human body, and has the beauty effect of moisturizing and moisturizing. High molecular weight hyaluronic acid or its salt can form mucosa in the stomach and intestines, thereby protecting the gastrointestinal tract, relieving lactic acid from irritating the stomach of people with damaged gastric mucosa, and having a protective effect on gastric mucosal damage. Medium molecular hyaluronic acid or its salt can promote intestinal barrier function, low molecular hyaluronic acid or its salt can be quickly absorbed by the human body, and guide the beneficial substances to be quickly absorbed. High, medium and low molecular hyaluronic acid or its salt has the effect of moisturizing and regulating the intestine. In addition, hyaluronic acid or its salt is colorless and tasteless, and will not cause functional flavored fermented milk to have peculiar smell.

(3) The present invention selects guar gum and pectin as stabilizers. Hyaluronic acid or its salt has extremely strong hydrophilicity and is a linear polysaccharide. It can have a strong adsorption effect with guar gum and can form a strong hydrogen bond with pectin molecules. Therefore, hyaluronic acid or its salt can be well compatible and composite with guar gum and pectin. Moreover, pectin and guar gum have a good synergistic effect. The composite of the three can greatly improve the viscosity of fermented milk, and the viscosity will not be greatly reduced during storage. In addition, pectin can be adsorbed on casein through electrostatic action. The synergistic effect of hyaluronic acid or its salt, guar gum and pectin can increase the hydration of the system and improve the stability of the formed network structure, thereby enhancing the water holding capacity of the gel in the fermented milk. While increasing the viscosity, it effectively avoids the phenomenon of syneresis and whey precipitation in raw milk, and also protects the stability of protein under heating conditions and the stability of the product state during transportation and storage.

(4) The stabilizer of the present invention and hyaluronic acid or its salt are difficult to dissolve and easy to form agglomerates. Adding them together will lead to low production efficiency. During the preparation process of the flavored fermented milk of the present invention, part of the solution is first heated to dissolve the stabilizer, so that the stabilizer is fully swollen, and then mixed with the remaining solution dissolved in other raw materials. The insoluble stabilizer and hyaluronic acid or its salt can be dissolved at the same time, thereby improving production efficiency and reducing the damage to the nutrients in milk and other functional ingredients such as hyaluronic acid or its salt by heating.

(5) The flavored fermented milk of the present invention uses functional sugar alcohols, which contain very low or no energy. It can be used to replace sucrose, has high safety and stability, and has a good taste, which meets the current consumer demand for a low-sugar diet.

(6) The interaction between hyaluronic acid or its salts, pectin, guar gum, and milk protein can make the flavored fermented milk more uniform in color, smoother in surface, more delicate, softer, smoother, mellower, and non-astringent in taste, and non-irritating when swallowed, which is more in line with the current consumer trend of pursuing both functionality and taste.

DETAILED DESCRIPTION

In order to better illustrate the technical solution of the present invention, the following examples are given, but the present invention is not limited to the following examples. In order to avoid too many unnecessary details, the well-known structures or functions will not be described in detail in the following examples. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs.

Unless otherwise specified, all raw material parts in the following examples are parts by weight.

Example 1

The formula of the flavored fermented milk containing hyaluronic acid of the present invention is: 850 parts of raw cow milk, 30 parts of skim milk powder, 10 parts of whey protein powder, 80 parts of sweetener, 9 parts of stabilizer, 6 parts of composite hyaluronic acid or its salt, 0.06 parts of starter, and 20 parts of prebiotics. Among them, the sweetener is erythritol, and the stabilizer is guar gum and pectin in a mass ratio of 9:1. The composite hyaluronic acid or its salt is a high molecular sodium hyaluronate, a medium molecular sodium hyaluronate and a low molecular sodium hyaluronate in a mass ratio of 2:3:1, the molecular weight of the high molecular sodium hyaluronate is 2×10 ⁶ Da, the molecular weight of the medium molecular sodium hyaluronate is 8×10 ⁵ Da, and the molecular weight of the low molecular sodium hyaluronate is 1×10 ⁵ Da. The starter is thermophilic streptococcus, bulgaricus lactobacillus and long bifidobacterium in a mass ratio of 5:2:1, and the prebiotic is oligoxylose.

The preparation method of flavored fermented milk containing hyaluronic acid is as follows:

(1) Raw milk is healthy, odorless, high in protein, antibiotic-free, and meets the standard requirements of GB19301. The raw milk is heated to 50°C, skim milk powder and whey protein powder are added, and stirred for 15 minutes;

(2) heating 25 wt% of the solution in step (1) to 65° C., adding a stabilizer, and stirring at high speed for 15 minutes;

(3) Cool the remaining solution of step (1) to 20° C., slowly add high-molecular sodium hyaluronate to the solution while stirring, gradually increase the stirring speed, stir until completely dissolved, continue to slowly add medium-molecular sodium hyaluronate, stir until completely dissolved, and finally add low-molecular sodium hyaluronate. After adding, continue stirring for 20 minutes, add the mixture of sweetener and prebiotics, stir for 10 minutes, and fully dissolve the materials;

(4) mixing the solutions of step (2) and step (3) and performing secondary homogenization. The secondary homogenization method can achieve uniform dispersion on the basis of crushing. The homogenization temperature is 65° C., the first stage homogenization pressure is 15 MPa, and the second stage homogenization pressure is 5 MPa.

(5) sterilizing the homogenized solution at a temperature of 90 to 95° C. for 5 to 10 minutes, and cooling the solution to 42 to 45° C. after sterilization;

(6) adding a fermentation agent to the solution of step (5) for heat preservation and fermentation, stirring for 10 minutes to evenly distribute the bacteria in the solution, maintaining the temperature at 43°C during fermentation, fermenting for 8 hours, and fermenting until the acidity reaches 72°T;

(7) The fermented product is cooled to 15° C., filled and sealed under the prescribed hygiene requirements, and refrigerated at 0 to 4° C. for 18 hours to obtain a flavored fermented milk product S1 containing hyaluronic acid.

Example 2

The flavored fermented milk product S2 was prepared according to the formula and method of Example 1, except that the composite hyaluronic acid or its salt was high molecular sodium hyaluronate, medium molecular sodium hyaluronate and low molecular sodium hyaluronate in a mass ratio of 2:1.5:0.5, the molecular weight of the high molecular sodium hyaluronate was 2.5×10 ⁶ Da, the molecular weight of the medium molecular sodium hyaluronate was 1.4×10 ⁶ Da, and the molecular weight of the low molecular sodium hyaluronate was 4×10 ⁵ Da.

Example 3

The flavored fermented milk product S3 was prepared according to the formula and method of Example 1, except that the composite hyaluronic acid or its salt was high molecular sodium hyaluronate, medium molecular sodium hyaluronate and low molecular sodium hyaluronate in a mass ratio of 2:4:3, the molecular weight of the high molecular sodium hyaluronate was 1.5×10 ⁶ Da, the molecular weight of the medium molecular sodium hyaluronate was 5×10 ⁵ Da, and the molecular weight of the low molecular sodium hyaluronate was 5×10 ³ Da.

Example 4

The flavored fermented milk product S4 was prepared according to the formula and method of Example 1, except that the stabilizer was guar gum and pectin in a mass ratio of 5:1.

Example 5

The flavored fermented milk product S5 was prepared according to the formula and method of Example 1, except that the stabilizer was guar gum and pectin in a mass ratio of 15:1.

Example 6

750 parts of raw milk, 25 parts of skim milk powder, 8 parts of whey protein powder, 45 parts of sweetener, 3 parts of stabilizer, 3 parts of composite hyaluronic acid or its salt, 0.02 parts of fermentation agent, and 5 parts of prebiotics. Among them, the sweetener is erythritol, and the stabilizer is guar gum and pectin in a mass ratio of 9:1. The composite hyaluronic acid or its salt is a high molecular sodium hyaluronate, a medium molecular sodium hyaluronate, and a low molecular sodium hyaluronate in a mass ratio of 2:3:1, wherein the molecular weight of the high molecular sodium hyaluronate is 2×10 ⁶ Da, the molecular weight of the medium molecular sodium hyaluronate is 8×10 ⁵ Da, and the molecular weight of the low molecular sodium hyaluronate is 1×10 ⁵ Da. The fermentation agent is thermophilic streptococcus, bulgaricus lactobacillus and long bifidobacterium in a mass ratio of 4:1:1, and the prebiotic is oligosaccharide.

The preparation method of flavored fermented milk containing hyaluronic acid is as follows:

(1) Raw milk is healthy, odorless, high in protein, antibiotic-free, and meets the standard requirements of GB19301. The raw milk is heated to 45°C, skim milk powder and whey protein powder are added, and stirred for 15 minutes;

(2) heating 20 wt% of the solution in step (1) to 60° C., adding a stabilizer, and stirring at high speed for 10 minutes;

(3) Cool the remaining solution of step (1) to 15° C., slowly add high-molecular sodium hyaluronate to the solution while stirring, gradually increase the stirring speed, stir until completely dissolved, continue to slowly add medium-molecular sodium hyaluronate, stir until completely dissolved, and finally add low-molecular sodium hyaluronate. After adding, continue stirring for 15 minutes, add the mixture of sweetener and prebiotics, stir for 10 minutes, and fully dissolve the materials;

(4) mixing the solutions of step (2) and step (3) and performing secondary homogenization. The secondary homogenization method can achieve uniform dispersion on the basis of crushing. The homogenization temperature is 60° C., the first-stage homogenization pressure is 10 MPa, and the second-stage homogenization pressure is 3 MPa.

(5) sterilizing the homogenized solution at a temperature of 90 to 95° C. for 5 to 10 minutes, and cooling the solution to 42 to 45° C. after sterilization;

(6) adding a fermentation agent to the solution of step (5) for heat preservation and fermentation, stirring for 10 minutes to evenly distribute the bacteria in the solution, maintaining the temperature at 42° C. during fermentation, fermenting for 4 hours, and fermenting until the acidity reaches 70° T;

(7) The fermented product is cooled to 13° C., filled and sealed under the prescribed hygiene requirements, and refrigerated at 0 to 4° C. for 12 hours to obtain a flavored fermented milk product S6 containing hyaluronic acid.

Example 7

950 parts of raw milk, 45 parts of skim milk powder, 15 parts of whey protein powder, 105 parts of sweetener, 15 parts of stabilizer, 9 parts of composite hyaluronic acid or its salt, 0.1 parts of leavening agent, and 30 parts of prebiotics. Among them, the sweetener is erythritol, and the stabilizer is guar gum and pectin in a mass ratio of 9:1. The composite hyaluronic acid or its salt is a high molecular sodium hyaluronate, a medium molecular sodium hyaluronate, and a low molecular sodium hyaluronate in a mass ratio of 2:3:1, wherein the molecular weight of the high molecular sodium hyaluronate is 2×10 ⁶ Da, the molecular weight of the medium molecular sodium hyaluronate is 8×10 ⁵ Da, and the molecular weight of the low molecular sodium hyaluronate is 1×10 ⁵ Da. The leavening agent is thermophilic streptococcus, bulgaricus lactobacillus and long bifidobacterium in a mass ratio of 9:3:1, and the prebiotic is oligosaccharide.

The preparation method of flavored fermented milk containing hyaluronic acid is as follows:

(1) Raw milk is healthy, odorless, high in protein, antibiotic-free, and meets the standard requirements of GB19301. The raw milk is heated to 55°C, skim milk powder and whey protein powder are added, and stirred for 20 minutes;

(2) heating 30 wt% of the solution in step (1) to 70° C., adding a stabilizer, and stirring at high speed for 15 minutes;

(3) Cool the remaining solution of step (1) to 25° C., slowly add high-molecular sodium hyaluronate to the solution while stirring, gradually increase the stirring speed, stir until completely dissolved, continue to slowly add medium-molecular sodium hyaluronate, stir until completely dissolved, and finally add low-molecular sodium hyaluronate. After adding, continue stirring for 20 minutes, add the mixture of sweetener and prebiotics, stir for 15 minutes, and fully dissolve the materials;

(4) mixing the solutions of step (2) and step (3) and performing secondary homogenization. The secondary homogenization method can achieve uniform dispersion on the basis of crushing. The homogenization temperature is 70° C., the first stage homogenization pressure is 20 MPa, and the second stage homogenization pressure is 8 MPa.

(5) sterilizing the homogenized solution at a temperature of 90 to 95° C. for 5 to 10 minutes, and cooling the solution to 42 to 45° C. after sterilization;

(6) adding a fermentation agent to the solution of step (5) for heat preservation and fermentation, stirring for 10 minutes to evenly distribute the bacteria in the solution, maintaining the temperature at 45° C. during fermentation, fermenting for 10 hours, and fermenting until the acidity reaches 72° T;

(7) The fermented product is cooled to 15° C., filled and sealed under the prescribed hygiene requirements, and refrigerated at 2 to 6° C. for 24 hours to obtain a flavored fermented milk product S7 containing hyaluronic acid.

Comparative Example 1

The flavored fermented milk product C1 was prepared according to the formula and method of Example 1, except that no high, medium or low sodium hyaluronate was added.

Comparative Example 2

The flavored fermented milk product C2 was prepared according to the formula and method of Example 1, except that the mass ratio of the high, medium and low molecular weight sodium hyaluronate was 2:1:0.2.

Comparative Example 3

The flavored fermented milk product C3 was prepared according to the formula and method of Example 1, except that the mass ratio of high, medium and low molecular weight sodium hyaluronate was 2:5:4.

Comparative Example 4

The flavored fermented milk product C4 was prepared according to the formula and method of Example 1, except that the high, medium and low sodium hyaluronates were replaced with only high molecular weight sodium hyaluronate.

Comparative Example 5

The flavored fermented milk product C5 was prepared according to the formula and method of Example 1, except that the stabilizer was replaced with gelatin and xanthan gum in a mass ratio of 9:1.

Comparative Example 6

The flavored fermented milk product C6 was prepared according to the formula and method of Example 1, except that the stabilizer was replaced with modified starch and carrageenan in a mass ratio of 9:1.

Comparative Example 7

The flavored fermented milk product C7 was prepared according to the formula and method of Example 1, except that the stabilizer was replaced with guar gum and pectin in a mass ratio of 1:9.

Comparative Example 8

The flavored fermented milk product C8 was prepared according to the formula and method of Example 1, except that no xylo-oligosaccharide was added.

Experimental example

1. Changes in physical, chemical and microbiological indicators of flavored fermented milk during storage

The whey precipitation rate, viscosity, consistency, lactic acid bacteria count and coliform group were measured during storage for the samples prepared in the above examples and comparative examples. The lactic acid bacteria count was measured in accordance with GB4789.35; the coliform group was measured in accordance with GB4789.3; the consistency was tested for texture; the viscosity was measured using a rotary viscometer at room temperature (25°C), using a No. 4 rotor, a speed of 20r/min, and a measurement time of 30s; the whey precipitation rate was measured as follows: 10g of the sample was placed in a clean funnel and filtered for 2 hours, and the filtrate was collected in a beaker and weighed, which is the mass of the whey precipitated in the sample. The whey precipitation rate of flavored fermented milk was calculated according to the following formula:

Flavored fermented milk whey precipitation rate (%) = mass of precipitated whey (g) / mass of sample (g) × 100%

The measurement results of each index are shown in Table 1.

Table 1 Results of physical, chemical and microbiological index determination during storage of flavored fermented milk

Note: Superscripts a-i indicate the differences between different treatment groups in each column, where different letters indicate significant differences in each column (P < 0.05).

As shown in Table 1, the whey precipitation rates of the samples prepared in the examples are lower than those of the control samples C1, C2, C3, C4, C5, C6, and C7, indicating that the compounding of sodium hyaluronate with a molecular weight and a ratio and a stabilizer according to the present invention can improve the whey precipitation phenomenon during the storage of flavored fermented milk; the decrease rates of the consistency and viscosity of the sample of Example 1 after storage for 14 days are lower than those of the samples of the comparative example, indicating that the compounding of sodium hyaluronate with a molecular weight and a ratio and a stabilizer according to the present invention can improve the decrease in the consistency and viscosity of flavored fermented milk during storage; the number of lactic acid bacteria of the sample of Example 1 is higher than that of the control samples C1-C8, and the number of lactic acid bacteria of the samples of all the examples is only slightly reduced after storage for 14 days, while the number of lactic acid bacteria of the samples of the control groups C1, C2, C3, C4, and C8 is lower than the limit of GB19302 after storage for 14 days, indicating that the sodium hyaluronate and prebiotics with a molecular weight and a ratio according to the present invention can improve the decrease in the number of beneficial bacteria during the storage of flavored fermented milk. The number of coliform bacteria in the samples of Example 1 was lower than that in the control samples C1-C8, and the number of coliform bacteria in the control group C1, C2, C3, C4, and C8 samples exceeded the limit of GB19302 after storage for 14 days, indicating that the sodium hyaluronate and prebiotics with the molecular weight and proportion described in the present invention can inhibit the growth of coliform bacteria during the storage of flavored fermented milk.

2. Determination of sensory indicators of flavored fermented milk

The sensory indexes of samples S1, S2, S3 and control samples C1, C2, C3, C4, C7 were measured according to GB19302-2010. The sensory index items include: appearance, tissue state (viscosity, whey precipitation), taste, flavor, sourness and sweetness, and overall acceptability. A total of 50 people participated in the sensory evaluation, and each person gave a score for each sample. The scoring range of each sensory evaluation item is 1 to 5 points, and the score is given according to the strength of the specific sensory index. The higher the score, the better the sensory quality of the product, and the lower the score, the worse the sensory quality of the product. 1 point, 2 points, 3 points, 4 points, and 5 points represent poor, general, better, good, and excellent respectively.

The sensory evaluation requirements are as follows:

Appearance: uniform color, smooth surface;

Tissue state: moderate viscosity, fine and uniform texture, no lumps, particles, and no whey precipitation;

Taste: soft, delicate, smooth, mellow, no irritation when swallowing;

Flavor: Pure and natural, no astringency or peculiar smell;

Sweet and sour: the sweet and sour ratio is appropriate;

Overall acceptability: Overall acceptability.

The results of sensory index determination are shown in Table 2.

Table 2 Results of sensory index determination of flavored fermented milk

As shown in Table 2, the indicators of S1, S2 and S3 are better than those of the control group, indicating that the formula of the present invention can improve the sensory quality of flavored fermented milk; the indicators of the C1 control group samples are significantly lower than those of other samples, indicating that sodium hyaluronate helps maintain the sensory quality of the product.

3. Study on the gastrointestinal protective effect of hyaluronic acid-flavored fermented milk

The efficacy of gastrointestinal protection was studied for samples S1, S2, S3 and control samples C1, C2, C3, C4, C8. 160 voluntary subjects with symptoms such as stomach discomfort, acid reflux, and constipation were recruited, divided into 8 groups with 20 subjects in each group, and patients with gastric ulcer were excluded.

Subject exclusion criteria:

(1) People under 18 years old or over 65 years old, pregnant or lactating women, or those who are allergic to this product;

(2) People with chronic gastritis and digestive system ulcers;

(3) Patients with severe systemic diseases of the cardiovascular, cerebrovascular, liver, kidney and hematopoietic systems;

(4) Those who frequently use drugs, are addicted to alcohol, or smoke heavily;

(5) Those who are taking other medications or receiving other treatments;

(6) Taking items related to the function being tested in the short term may affect the judgement of the results;

(7) The test sample is not taken according to the regulations, the efficacy cannot be judged, or the data is incomplete, which affects the judgment of efficacy or safety.

The subjects drank one bottle of the test sample every day for 15 consecutive days. After the 15th day, they filled out a questionnaire covering the degree of improvement of symptoms such as stomach pain, belching, acid reflux, abdominal distension, abdominal pain, and constipation.

Judge according to the following criteria:

The results of the effective and ineffective number and percentage of gastrointestinal protection in each group of subjects after taking the medicine for 15 days are shown in Table 3.

Table 3 Effect of hyaluronic acid flavored fermented milk on gastrointestinal protection

As shown in Table 3, the indicators of S1, S2 and S3 are better than those of the control group, indicating that the flavored fermented milk of the formula of the present invention can regulate the gastrointestinal tract and moisten the intestines and promote bowel movements; the indicators of the C1 control group samples are significantly lower than those of other samples, indicating that the addition of sodium hyaluronate is helpful for gastrointestinal protection; the indicators of the C8 control group samples are lower than those of S1, indicating that the addition of prebiotics can further affect the protective effect of flavored fermented milk on the gastrointestinal tract.

4. Study on the efficacy of hyaluronic acid-flavored fermented milk in improving skin moisture

The efficacy of improving skin moisture was studied on samples S1, S2, S3 and control samples C1, C2, C3, C4. 140 healthy subjects aged 30 to 50 years old were recruited and randomly divided into 7 groups, with 20 subjects in each group.

Subject exclusion criteria:

(1) Pregnant or lactating women, or those who are allergic to this product;

(2) Patients with cardiovascular, hepatic, renal, hematopoietic systemic diseases and a history of mental illness;

(3) Taking items related to the function being tested in the short term may affect the judgement of the results;

(4) Those who fail to take the test sample according to the experimental requirements and whose efficacy cannot be determined or whose incomplete data affect the judgment of efficacy or safety.

The subjects drank one bottle of the test sample every day for 15 consecutive days. The moisture of the forehead and brow skin was tested before and after the 15th day of taking it: it was carried out in a spacious, well-ventilated examination room with stable temperature, humidity and other spatial environments. In a quiet state, clean the tested area with a clean cotton ball dipped in distilled water, and the moisture was measured 15 minutes after drying. The measurement work before and after the tasting was performed by the same instrument and the same person.

Judge according to the following criteria:

Ineffective: An increase in skin moisture content of less than 5% or a decrease in skin moisture content compared to the initial skin moisture content.

Effective: Increase in skin moisture content by more than 5% compared to initial skin moisture content.

The results of the effective and ineffective number and percentage of subjects in each group whose skin moisture was improved after taking the medicine for 15 days are shown in Table 4.

Table 4 Effect of hyaluronic acid flavored fermented milk on skin moisture

As shown in Table 4, S1, S2, and S3 are all better than the control group, indicating that the flavored fermented milk of the present invention can improve skin moisture; the percentage of the C1 control group sample is significantly lower than that of the other samples, indicating that the addition of sodium hyaluronate helps to improve skin moisture.

It can be seen from the above experimental results that the flavored fermented milk containing hyaluronic acid of the present invention has a low whey precipitation rate during storage, stable viscosity, consistency and lactic acid bacteria count, slows the growth of coliform group, can maintain its quality and extend its shelf life; has good sensory quality, no obvious sensory visible dehydration shrinkage, whey precipitation phenomenon, does not contain peculiar smell, has a delicate, smooth and mellow taste without astringency, and has a high overall acceptability; has the function of regulating the gastrointestinal tract and improving skin moisture, and is more suitable for people with damaged gastric mucosa.

The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (12)

1. The flavored fermented milk containing the hyaluronic acid is characterized by comprising the following raw materials in parts by weight: 750-950 parts of raw milk, 3-15 parts of stabilizer, 3-9 parts of compound hyaluronic acid or salt thereof, 0.02-0.1 part of starter and 5-30 parts of prebiotics; the compound hyaluronic acid or salt thereof is a composition of high molecular hyaluronic acid or salt thereof, medium molecular hyaluronic acid or salt thereof and low molecular hyaluronic acid or salt thereof, wherein the molecular weight of the high molecular hyaluronic acid or salt thereof is 1.5 multiplied by 10 ⁶Da~2.5×10⁶ Da, the molecular weight of the medium molecular hyaluronic acid or salt thereof is 5 multiplied by 10 ⁵Da~1.4×10⁶ Da, and the molecular weight of the low molecular hyaluronic acid or salt thereof is 5 multiplied by 10 ³Da~4×10⁵ Da; the mass ratio of the high molecular hyaluronic acid or the salt thereof to the medium molecular hyaluronic acid or the salt thereof to the low molecular hyaluronic acid or the salt thereof is 2: 1.5-4: 0.5-3; the stabilizer is a mixture of guar gum and pectin, and the mass ratio of the guar gum to the pectin is 5-15: 1, a step of; the hyaluronate includes sodium, zinc, calcium or potassium salt of hyaluronic acid.

2. The flavored fermented milk of claim 1, wherein: the mass ratio of guar gum to pectin is 7-12: 1.

3. The flavored fermented milk of claim 1, wherein: the prebiotics are one or more of fructo-oligosaccharide, galacto-oligosaccharide, xylo-oligosaccharide, malto-oligosaccharide and polydextrose.

4. The flavored fermented milk of claim 1, wherein: the starter is Streptococcus thermophilus, lactobacillus bulgaricus and Bifidobacterium.

5. The flavored fermented milk of claim 4, wherein: the mass ratio of streptococcus thermophilus to lactobacillus bulgaricus to bifidobacterium is 4-9: 1-3: 1.

6. The flavored fermented milk of claim 4, wherein: the Bifidobacterium is one or more of Bifidobacterium adolescentis, bifidobacterium lactis, bifidobacterium bifidum, bifidobacterium breve, bifidobacterium infantis and Bifidobacterium longum.

7. The flavored fermented milk of claim 1, wherein: the milk powder beverage also comprises a flavor regulator, wherein the flavor regulator is at least one of skim milk powder, whey protein powder and sweetener.

8. The flavored fermented milk of claim 7, wherein: the sweetener is one or more of erythritol, xylitol, lactitol, mannitol, sorbitol, maltitol and isomalt.

9. The flavored fermented milk of claim 7, wherein: the mass ratio of the skim milk powder to the whey protein powder is 1-8: 1.

10. The flavored fermented milk of claim 9, wherein: the mass ratio of the skim milk powder to the whey protein powder is 2-5: 1.

11. A method for producing the hyaluronic acid-containing flavored fermented milk according to any of claims 7 to 10, characterized by comprising the steps of:

(1) Heating raw milk, adding skimmed milk powder and whey protein powder, and stirring;

(2) Taking 20-30wt% of the mixture obtained in the step (1), heating, adding a stabilizer, and uniformly stirring;

(3) Taking the rest mixture in the step (1), cooling, adding compound hyaluronic acid or salt thereof, stirring uniformly, then continuously adding sweetener and prebiotics, and stirring uniformly again;

(4) Mixing the mixtures in the steps (2) and (3) and carrying out two-stage homogenization;

(5) Sterilizing the homogenized mixture, then cooling to the fermentation temperature, and adding a starter for heat preservation and fermentation;

(6) And cooling, filling, refrigerating and curing the fermented product to obtain the flavored fermented milk containing hyaluronic acid.

12. The method for preparing the composite material according to claim 11, wherein: in the step (1), the temperature is raised to 45-55 ℃; in the step (2), the temperature is raised to 60-70 ℃; in the step (3), the temperature is reduced to 15-25 ℃; in the step (4), the temperature of the first-stage homogenization is 55-75 ℃, the homogenization pressure is 10-20 MPa, the temperature of the second-stage homogenization is 55-75 ℃, and the homogenization pressure is 3-8 MPa; in the step (5), the fermentation temperature is 42-45 ℃ and the acidity is 70-72 ℃.