KR19990041424A - Fermented milk with improved stability by adding modified whey protein and its manufacturing method - Google Patents

Abstract

The present invention relates to fermented milk to which modified whey protein is added in order to improve physical properties and stability of fermented milk, and a method of manufacturing the same.

The fermented milk according to the present invention is characterized by inoculating lactic acid bacteria starter after dissolving and sterilizing skim milk powder and denatured whey protein in raw material oil and culturing at a predetermined temperature. Contains 20% by weight of denatured whey protein.

Fermented milk containing modified whey protein prepared according to the present invention can improve the physical properties and stability of fermented milk without using conventional stabilizers such as pectin, thereby improving the problems of conventional fermented milk such as whey separation. In the case of a kind of milk ingredient, stabilizers such as pectin can maintain the intrinsic taste of milk even when a considerable amount is used, and the solubility in crude oil is also easy to use in the manufacturing process.

In addition, the fermented milk containing the modified whey protein prepared according to the present invention can also be utilized as a product fortified protein compared to the conventional fermented milk.

Description

Fermented milk with improved stability by adding modified whey protein and its manufacturing method

The present invention relates to fermented milk to which modified whey protein is added in order to improve physical properties and stability of fermented milk, and a method of manufacturing the same.

Yoghurt refers to fermented milk formed by lactobacillus or yeast proliferating in milk of mammals such as milk or sheep milk, and milk protein coagulated by the acid produced. Currently in Korea, fermented milk is classified into liquid fermented milk (3% or more) and staple fermented milk (8% or more) based on the content of nonfat milk solids under the Food Act. It is divided into Stirred type) and Liquid type Drink type.

Proteins in milk lose stability and precipitate due to the acid produced by lactic acid bacteria, and the precipitated protein molecules clump together to form a curd in the form of curd, called curd. It is called). Whey proteins are largely divided into casein and whey proteins according to their size and properties.The non-uniform phosphoprotein that precipitates when the fat is removed is pH 4.6. Casein is the protein that remains in the supernatant. It is called.

In most cases, milk becomes semi-solid as the protein precipitates from a stable liquid state in the fluid phase during fermentation. At this time, the curd formed as the casein is entangled causes the water to leak out due to external weak impact. The aqueous solution at this time is called whey, and this phenomenon is called whey separation. Whey separation occurs mainly in staple fermented milk products having a high content of nonfat milk solids. This whey separation is the most common product defects that can occur in fermented milk, the off-white liquid is present on the surface of the product, there is no problem in the nutrition of the product, but there is a problem that the texture of the appearance is poor.

Therefore, most fermented milks use stabilizers to compensate for these defects and to improve the structure and viscosity of the product. At this time, the stabilizers used are citrus pectin, apple pectin, and gum (depending on the raw material). gums, starch and the like. Most fermented milks produced in Korea mainly use citrus-based pectin as a stabilizer, but due to the characteristics of pectin, it is difficult to disperse them at low temperatures, and when a large amount is used, there is a problem in that the product is already smelled or smelled. have.

Accordingly, the present inventors have developed a fermented milk having excellent physical properties and stability using whey protein without using a stabilizer such as pectin while researching to improve the quality of fermented milk. In other words, it was found that the denatured whey protein obtained by enzymatic treatment of whey protein, which is a kind of milk component, has an excellent effect on the organization and viscosity of fermented milk. Whey protein has been used as a raw material for fermented milk, and has been used as an ingredient for immune fortification, protein fortification, feed additives, and ice cream. Denatured whey protein enzyme-treated whey protein is a kind of milk component. It can maintain the original taste of milk as it is used, there is no restriction on the amount of use unlike conventional pectin, and also easy to use with the same excellent solubility as skim milk powder.

Conventional method for producing fermented milk is to add skim milk powder to raw milk, sterilize nonfat milk solids to 3 to 16% by weight, sterilize, inoculate with lactic acid bacteria starter, incubate at a certain temperature, and then use various juices, sweeteners and stabilizers (pectin). Compared to mixing and homogenizing the prepared syrup, the method for producing fermented milk according to the present invention is dissolved and sterilized skim milk powder and modified whey protein, and then inoculated with lactic acid bacteria starter and incubated at a constant temperature, the culture completed liquid It is characterized by mixing and homogenizing the syrup made of various juices and sweeteners.

The present invention improves the physical properties and stability of fermented milk without affecting the taste of fermented milk by adding modified whey protein enzyme-treated whey protein, which is a kind of milk component, to fermented milk, thereby improving problems such as whey separation from fermented milk. It aims to do it.

In addition, an object of the present invention is to increase the usability of whey protein, which was generated as a by-product after cheese production and had low usability.

Figure 1 is a graph showing the viscosity change of the stud yogurt with temperature according to the addition of the denatured whey protein.

Fermented milk according to the present invention is characterized in that the skim milk powder and the modified whey protein are dissolved in raw material oil and sterilized, and then inoculated with a lactic acid bacteria starter and cultured at a predetermined temperature.

In more detail, adding skim milk powder to raw milk to adjust the content of nonfat milk solids to 8 to 20% by weight, dissolving the denatured whey protein in the adjusted raw milk, sterilizing heat treatment, and inoculating the lactic acid bacteria starter at a constant temperature. After incubation, the culture completion liquid is cooled, and the fermented milk containing the modified whey protein according to the present invention can be obtained by mixing and homogenizing a syrup composed of various juices and sweeteners.

Fermented milk prepared according to the present invention preferably contains from 0.1 to 20% by weight of modified whey protein, depending on the form of the product. Denatured whey protein can be obtained by treating whey protein with protease, and this denatured whey protein is excellent in tissue improvement effect of fermented milk. Therefore, there is no limit on the amount used, and solubility in crude oil is also easy to use.

Sterilization heat treatment of the raw material oil after adding skim milk powder and modified whey protein is performed according to a conventional method, Preferably it sterilizes for 15 second at 72-75 degreeC.

Cooling of the culture completion liquid can be normally performed using cooling water or cold air in a culture tank.

The syrup mixed in the culture complete solution is mainly made by dissolving juice, dietary fiber, glucose, oligosaccharide, calcium, etc. in purified water, sterilizing and cooling it, and mixing and stirring the culture solution and the syrup at a predetermined ratio to obtain fermented milk as a final product. do.

In addition, the fermented milk prepared according to the present invention may further include one or two or more components selected from water, vitamins, minerals, sugars, fruits, grains, vegetables, and organic acids. The vitamins include vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin E, folic acid, niacin, and the minerals include calcium and iron. The grains and vegetables include carrots, pumpkins, sweet potatoes, tomatoes, wheat, rice and beans, and the organic acid includes citric acid, succinic acid or tartaric acid.

According to the present invention containing the modified whey protein as an active ingredient, the preferred composition of the fermented milk is shown in Table 1.

Table 1. Composition of fermented milk according to the present invention

In addition, the fermented milk according to the present invention can be produced in various forms of products, such as liquid, arc or drink yogurt.

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples are not to be construed as limiting the invention, of course, and ordinary changes may be made by those skilled in the art within the scope of the invention.

Example 1

[Manufacture of Fermented Milk]

Crude milk powder and modified whey protein were mixed and dissolved in crude milk to adjust the nonfat milk content to 15% by weight, and then sterilized at 75 ° C. for 15 seconds. After the sterilized raw material oil was cooled, the inoculated lactic acid bacteria starter was inoculated to incubate until pH 4-5, and the culture solution was cooled after completion of the culture.

On the other hand, after cutting the pulp to a certain size, purified water, sugar, pectin, flavorings, etc. were added, heated to sterilize and concentrated to prepare a fruit chopped fruit 50% by weight. After cooling the prepared fruit 에 it was added to the culture to make the desired fermented milk.

Example 2

[Manufacture of Fermented Milk]

Crude milk powder and modified whey protein were mixed and dissolved in crude milk to adjust the nonfat milk content to 15% by weight, and then sterilized at 75 ° C. for 15 seconds. After the sterilized raw material oil was cooled, the inoculated lactic acid bacteria starter was inoculated to incubate until pH 4-5, and the culture solution was cooled after completion of the culture.

Meanwhile, a syrup was prepared by dissolving juice, dietary fiber, glucose, oligosaccharide, calcium, and the like in purified water. The syrup thus prepared was sterilized and then cooled, and the desired fermented milk was prepared by mixing and stirring the homogenate with the culture solution.

Example 3

[Measurement of Viscosity Change of Product]

Samples were prepared as shown in Table 2 to measure the effect of improving the viscosity of the denatured whey protein. That is, Sample A was prepared in the same manner as in Example 1, and Sample B was prepared in the same manner as in Example 1 except that the nonfat milk solid content was adjusted using only skim milk powder without adding modified whey protein. Sample C was prepared in the same manner as Sample B except that 0.2% of stud yogurt pectin was added to the culture.

Table 2. Composition of Samples for Viscosity Measurement

Viscosity change of the product with temperature was measured using a viscometer (Brookfield Viscometer) for each sample, the results are shown in FIG.

As can be seen from FIG. 1, the sample having the modified whey protein added (sample A) was superior to the sample having no added sample (sample B), and the effect of temperature was also low. In addition, when the modified whey protein was added (Sample A), the effect was similar to the conventional pectin (Sample C) for the purpose of viscosity improvement.

Example 4

[Measurement of precipitation prevention effect of the product]

Samples were prepared as shown in Table 3 in order to measure the precipitation preventing effect of the modified whey protein product. That is, sample a was prepared in the same manner as in Example 2, and sample b was prepared in the same manner as in Example 2, except that the nonfat milk solid content was adjusted using only skim milk powder without adding modified whey protein. Sample c was prepared in the same manner as sample b except that 0.3% of pyotin for drink yogurt was added to the syrup.

Table 3. Sample Composition for Determination of Sedimentation Effects

After collecting a certain amount of each sample into a centrifuge tube and centrifuged at 3,000 rpm for 30 minutes at 5 ℃, the tube was left inverted at room temperature for 30 minutes and then the amount remaining in the tube was measured, Precipitation was measured using, and the results are shown in Table 4.

Table 4. Effect of Precipitation on Denatured Whey Protein

As can be seen from Table 4, compared with the sample (sample a) to which the modified whey protein was added (sample b), the precipitation tended to be remarkably decreased, and thus there was an excellent effect on preventing precipitation. The effect was similar to the pectin used (sample c).

Example 5

[Whey separation phenomenon observation]

Using the sample of Example 4 was observed for whey separation while refrigerated for two weeks. As a result, whey separation was not observed in sample a with denatured whey protein and sample c with pectin, but sample b was observed after 2 days of storage.

Fermented milk containing modified whey protein prepared according to the present invention improves the physical properties and stability of the product without using a conventional stabilizer such as pectin, thereby improving problems of fermented milk such as whey separation, and in the case of modified whey protein milk. It is a kind of ingredient, unlike pectin stabilizer is limited in the amount of use, it can maintain the intrinsic taste of milk even if a considerable amount is used, and because it has excellent solubility like skim milk powder in crude oil, it is easy to use in the manufacturing process.

In addition, the fermented milk containing the modified whey protein prepared according to the present invention can also be utilized as a product fortified protein compared to the conventional fermented milk.

Claims (8)

A fermented milk comprising liquid yogurt, staple yogurt, and drink yogurt, the fermented milk comprising a denatured whey protein treated with whey protein as a protease as an active ingredient for improving the physical properties and stability of the fermented milk. The method of claim 1, Fermented milk, characterized in that the modified whey protein is contained in 0.1 to 20% by weight. The method of claim 1, The fermented milk further comprises one or two or more components selected from water, vitamins, minerals, sugars, fruits, grains, vegetables and organic acids. The method of claim 3, The mineral fermented milk, characterized in that containing calcium and iron. The method of claim 3, The grains and vegetables are fermented milk, characterized in that containing carrots, pumpkins, sweet potatoes, tomatoes, wheat, rice and soybeans. The method of claim 3, The vitamin is vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin E, folic acid (folic acid), fermented milk characterized in that it contains niacin. The method of claim 3, Fermented milk, characterized in that the organic acid comprises citric acid, succinic acid or tartaric acid. In the method of manufacturing fermented milk containing liquid yogurt, staple yogurt and drink yogurt, the modified whey protein treated with whey protein as a protease is dissolved and sterilized in raw milk as an active ingredient for improving the physical properties and stability of fermented milk. , Inoculated with a starter for lactic acid bacteria and a method of producing fermented milk, characterized in that the culture at a constant temperature.