CN111758780A

CN111758780A - Drinking type yoghourt and preparation method thereof

Info

Publication number: CN111758780A
Application number: CN202010784280.5A
Authority: CN
Inventors: 李佟
Original assignee: Nanjing Fenchem Biological Technology Co ltd
Current assignee: Nanjing Fenchem Biological Technology Co ltd
Priority date: 2020-08-06
Filing date: 2020-08-06
Publication date: 2020-10-13

Abstract

The invention discloses a drinking yoghurt and a preparation method thereof, wherein the preparation method comprises the following steps of (1) heating raw milk, adding a first premix, and stirring; (2) adding the second premix and stirring; (3) homogenizing, sterilizing, cooling, inoculating, and fermenting until acidity reaches 70-75 ° T; (4) and (5) demulsifying and cooling, and then carrying out secondary homogenization. The invention selects the zero-strength agar to replace part of pectin as the yoghurt stabilizer, enhances the stability of the drinking yoghurt system, improves the green and astringent taste, and increases the protein content to meet the requirements of specific consumer groups. The zero-strength agar is applied to the yoghourt product for the first time in China.

Description

Drinking type yoghourt and preparation method thereof

Technical Field

The invention belongs to the technical field of yogurt preparation, and particularly relates to drinking yogurt and a preparation method thereof.

Background

With the continuous progress of society and the continuous improvement of living standard of people, the demand of people on dairy products is gradually improved. Fermented milk is an important member of dairy products, and is popular among people due to unique flavor and extremely high nutritional and health-care values. Besides the beneficial effects of the live bacteria and the metabolites on intestinal peristalsis and immunity improvement, part of the protein is more easily decomposed into polypeptide and amino acid, and part of the fat and lactose are also decomposed into smaller compounds which are easily absorbed by the human body. The yoghourt is a milk product prepared by taking milk as a raw material, adding a fermenting agent such as lactobacillus and the like into the milk after sterilization and fermenting. The traditional yogurt production mode divides yogurt into stirring yogurt and set yogurt. The set yogurt is filled firstly and then fermented, is in a complete tissue state, and the finished product has strong scooping feeling, fine taste but single taste, and can not be directly drunk but only be scooped; the stirring type yoghourt is formed by stirring fermented curd into a viscous tissue state before and during filling, various jam juices or other auxiliary materials can be added on line, and the yoghourt has a lot of tastes but is not suitable for large-mouth drinking due to thick mouthfeel. At present, the yoghurt in the market is mainly set type and stirring type, and in order to respond the demand of the market for refreshing yoghurt, a small amount of drinking yoghurt is appeared in the market. The drinking yoghurt is prepared by fermenting and demulsifying, and then making the feed liquid pass through equipment with a refining function, so that the yoghurt has low viscosity, can be directly drunk like a beverage in a large mouth, and has fresh and fine mouthfeel. The existing drinking yoghurt is divided into low-temperature and normal-temperature drinking yoghurt. Pectin is mostly used as a stabilizer in low-temperature drinking yoghurt, unstable phenomena such as whey precipitation and the like easily occur in the product, the protein content is low, and the taste is astringent; the normal-temperature drinking yoghurt uses various food additives as yoghurt stabilizers, and has strong and not fresh mouthfeel although the astringent taste is removed.

The agar is prepared from high-quality natural agar, Gracilaria verrucosa, thallus Porphyrae, etc. by refining and purifying with scientific methodNatural polymerThe polysaccharide substance belongs to plants with the highest content of soluble dietary fiber, has extremely low calorie, is easy to feel full, and has the functions of reducing blood pressure and cholesterol, preventing colorectal cancer and the like. The zero-strength agar is prepared from common agar through a special process, not only has the common characteristics of the agar, but also has the functional characteristics that the common agar cannot replace, such as better water solubility, lower dissolution temperature, lower gel strength, better water retention property, favorable absorption by human body and the like; has more uniform molecular chain structure and stable product performance. However, no report on the application of the zero-strength agar in the yogurt exists at present.

At present, stabilizers such as agar, pectin and gellan gum are reported to be adopted to develop normal-temperature drinking yoghurt; pectin and oligosaccharide are adopted to develop low-temperature drinking yoghurt; however, no report has been made on the development of drinking yoghurts using zero strength agar and pectin. The normal-temperature drinking yoghurt uses more additives and more labels, and is not approved by consumers. The low-temperature drinking yoghurt adopting pectin as a main stabilizer has poor stability and astringent taste. The zero-strength agar can enable the product to have more smooth and fine mouthfeel, rich flavor release, fat-like feeling and good stacking feeling in the application of the dairy product. The zero-strength agar also has good suspensibility, and the protein content of the drinking yoghurt can be improved according to the characteristic, so that the product has higher nutritional characteristics and meets certain specific consumer groups (such as body-building groups).

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention has been made in view of the above-mentioned technical drawbacks.

Therefore, as one aspect of the invention, the invention overcomes the defects in the prior art and provides drinking yoghurt and a preparation method thereof.

In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of drinking yoghurt comprises (1) heating raw milk, adding a first premix, and stirring; (2) adding the second premix and stirring; (3) homogenizing, sterilizing, cooling, inoculating, and fermenting until acidity reaches 70-75 ° T; (4) and (5) demulsifying and cooling, and then carrying out secondary homogenization.

Preferably, in the step (1), the raw milk is heated circularly at 60 ℃ for 30min, the stirring time is 20min, the homogenization in the step (3) is carried out at 65-70 ℃ and under 15-18MPa, the pasteurization is carried out at 95 ℃ for 5min, the fermentation temperature is 43 ℃ and the fermentation time is 5-6h, and the homogenization in the step (4) is carried out at 20-25 ℃ and under 6-8 MPa.

Preferably, the fermentation is further refrigerated and after-ripened, wherein the storage temperature in the refrigeration is 2-4 ℃, and the after-ripened time is at least 12 h.

Preferably, the first premix is a premix of sugar and milk protein powder; the second premix is a premix of pectin, zero-strength agar and sugar.

Preferably, by mass, 90-95% of raw milk, 5-8% of white granulated sugar, 0.6-1% of milk protein powder, 0.1-0.15% of zero-strength agar and 0.05-0.1% of pectin.

Preferably, the milk comprises, by mass, 91.8% of raw milk, 7% of white granulated sugar, 1% of milk protein powder, 0.12% of zero-strength agar and 0.08% of pectin.

Preferably, the inoculation is performed by fermentation strain YF-L822 of Kehansen.

The invention has the beneficial effects that:

the product selects zero-strength agar to replace part of pectin as a yoghurt stabilizer, enhances the stability of a drinking yoghurt system, improves the green and astringent taste, and increases the protein content to meet specific consumer groups. The zero-strength agar is applied to the yoghourt product for the first time in China.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 shows the results of the stability test of the yogurt prepared in example 7;

FIG. 2 shows the results of the stability tests of the yoghurts prepared in examples 1 to 3.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

The product adopts secondary homogenization, has short texture, fresh and fine taste and high nutritional value, and the drinking yoghurt belongs to the category of yoghurt, namely the content of raw milk is more than or equal to 80 percent. The taste of the product of the invention is investigated, and the scoring standards are as follows:

index (I)	Is very dislike	Is not too much like	In general	Relatively like	Very much like
						Viscosity of the oil	1	2	3	4	5
Sweet and sour ratio	1	2	3	4	5
						Refreshing feeling	1	2	3	4	5
Milk flavor	1	2	3	4	5
						Global like degree	1	2	3	4	5

Example 1:

the raw material formula is as follows:

91.05% of raw milk, 8% of white granulated sugar, 0.8% of milk protein powder, 0.1% of zero-strength agar, 0.05% of pectin and 0.0035% of strain.

1. The method comprises the following steps:

weighing, proportioning → stirring → constant volume → homogenizing → sterilizing → inoculating and fermenting → super cooling → secondary homogenizing → filling → refrigerating and warehousing

2. Description of the procedure

(1) Circularly heating raw milk at 60 deg.C for 30min, adding sugar and milk protein powder premix, and stirring;

(2) adding pectin, agar and sugar premix after a period of time, and stirring for 20 min;

(3) homogenizing the raw milk with the homogenized material, wherein the homogenizing condition is as follows: 65-70 ℃ and 15-18 MPa;

(4) standardizing raw milk after homogenizing, and then performing pasteurization at 95 ℃ for 5 min;

(5) after sterilization, cooling inoculation is carried out;

(6) fermenting at 43 ℃ for 5-6h, and performing demulsification and cooling after the acidity of the product reaches 72 DEG T;

(7) after cooling, carrying out secondary homogenization on the fermented milk, wherein the temperature is 20-25 ℃, and the pressure is 6-8 MPa;

(8) and finally cooling and filling.

The drinking yoghurt obtained by the embodiment is milky white and uniform in color; the yoghourt has the special fermented milk fragrance of yoghourt and stronger protein fragrance; the texture is uniform, no obvious air bubbles exist, no clotting phenomenon exists, no whey is separated out, the viscosity is low, and the viscosity is 569 cP; has delicate and soft taste, refreshing and delicious taste and higher sweetness.

Example 2:

the raw material formula is as follows:

91.8 percent of raw milk, 7 percent of white granulated sugar, 1 percent of milk protein powder, 0.12 percent of zero-strength agar, 0.08 percent of pectin and 0.0035 percent of strain.

1. The method comprises the following steps:

2. Description of the procedure

(1) Circularly heating raw milk, adding sugar and milk protein powder premix, and stirring;

(2) adding pectin, agar and sugar premix after a period of time, and stirring;

(4) standardizing raw milk after homogenizing, and then carrying out pasteurization;

(5) after sterilization, cooling inoculation is carried out;

(6) performing demulsification and cooling after the acidity of the product reaches 72 DEG T;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally cooling and filling.

The drinking yoghurt obtained by the embodiment is milky white and uniform in color; the yoghourt has the special fermented milk fragrance of yoghourt and stronger protein fragrance; the texture is uniform, no obvious air bubbles exist, no clotting phenomenon exists, no whey is separated out, the viscosity is low, and the viscosity is 625 cP; has delicate and soft taste, refreshing and delicious taste and moderate sour-sweet degree.

Example 3:

the raw material formula is as follows:

94.15 percent of raw milk, 5 percent of white granulated sugar, 0.6 percent of milk protein powder, 0.15 percent of zero-strength agar, 0.1 percent of pectin and 0.0035 percent of strain.

1. The method comprises the following steps:

2. Description of the procedure

(2) adding a premix of pectin, agar and sugar after a period of time, and stirring;

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally cooling and filling.

The drinking yoghurt obtained by the embodiment is milky white and uniform in color; the yoghourt has the special fermented milk fragrance of the yoghourt and light protein fragrance; the texture is uniform, no obvious air bubbles exist, no clotting phenomenon exists, no whey is separated out, the viscosity is moderate, and the viscosity is 819 cP; has delicate and soft taste, fresh and delicious taste and higher acidity.

Example 4:

the raw material formula is as follows:

93.77 percent of raw milk, 6 percent of white granulated sugar, 1 percent of milk protein powder, 0.13 percent of zero-strength agar, 0.1 percent of pectin and 0.0035 percent of strain.

1. The method comprises the following steps:

2. Description of the procedure

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally cooling and filling.

The drinking yoghurt obtained by the embodiment is milky white and uniform in color; the yoghourt has the special fermented milk fragrance of yoghourt and stronger protein fragrance; the texture is uniform, no obvious air bubbles exist, no clotting phenomenon exists, no whey is separated out, the viscosity is low, and the viscosity is 773 cP; has delicate and soft taste, refreshing and delicious taste and high acidity.

Example 5

The raw material formula is as follows:

87.3 percent of raw milk, 7 percent of white granulated sugar, 1 percent of milk protein powder, 0.12 percent of zero-strength agar, 0.08 percent of pectin, 4.5 percent of passion fruit jam and 0.0035 percent of strain.

1. The method comprises the following steps:

2. Description of the procedure

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally, cooling, adding passion fruit jam (the microbial indexes are detected before adding materials, the mold is required to be less than or equal to 30CFU/g, the yeast is required to be less than or equal to 10CFU/g, and staphylococcus aureus, salmonella and escherichia coli cannot be detected) on line, and then filling.

The drinking yoghurt obtained by the embodiment is light yellow, and the color is relatively uniform; the yoghourt has the special fermented milk fragrance of yoghourt, and has stronger fruit fragrance and no obvious protein fragrance; the texture is uniform, no obvious air bubbles exist, no clotting phenomenon exists, no whey is separated out, the viscosity is low, and the viscosity is 688 cP; has delicate and soft taste, refreshing and delicious taste, higher sweetness and richer flavor.

Example 6

The raw material formula is as follows:

87.3 percent of raw milk, 7 percent of white granulated sugar, 1 percent of milk protein powder, 0.12 percent of zero-strength agar, 0.08 percent of pectin, 4.5 percent of mixed berry jam and 0.0035 percent of strain.

1. The method comprises the following steps:

2. Description of the procedure

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally, cooling, adding the mixed berry jam on line (detecting microbial indexes before adding materials, wherein the requirement that mould is less than or equal to 30CFU/g, the requirement that yeast is less than or equal to 10CFU/g, and staphylococcus aureus, salmonella and escherichia coli cannot be detected), and then filling.

The drinking yoghurt obtained by the embodiment is light red, and the color is relatively uniform; the yoghourt has the special fermented milk fragrance of yoghourt, and has stronger fruit fragrance and no obvious protein fragrance; the texture is uniform, no obvious air bubbles exist, no clotting phenomenon exists, no whey is separated out, the viscosity is low, and the viscosity is 726 cP; has delicate and soft taste, refreshing and delicious taste, higher sweetness and richer flavor.

Example 7: pectin as a single stabilizer

The raw material formula is as follows:

sample No. 1: 91.9 percent of raw milk, 7 percent of white granulated sugar, 1 percent of milk protein powder, 0.1 percent of pectin and 0.0035 percent of strain.

Sample No. 2: 91.875% of raw milk, 7% of white granulated sugar, 1% of milk protein powder, 0.125% of pectin and 0.0035% of strain.

Sample No. 3: 91.85% of raw milk, 7% of white granulated sugar, 1% of milk protein powder, 0.15% of pectin and 0.0035% of strain.

1. The method comprises the following steps:

2. Description of the procedure (three samples being identical in process)

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally cooling and filling.

In the embodiment, some samples of the drinking yoghurt prepared by using pectin have a whey separation phenomenon in a stability test, and the three products have the same formula process except for different addition amounts of pectin. As shown in fig. 1, the top whey is separated from left to right, and the samples 1, 2 and 3 are respectively, after 21 days of stability observation, 3 samples are found to start separating from the top on day 15, and are visible to the naked eye, the whey separated from sample 1 is the most, the whey separated from sample 2 is the second most, and the whey separated from sample 3 is the least), and most of the testers react with sour and astringent feelings in the taste test (specifically, as shown in the following tables 1.1-1.2).

TABLE 1.1

TABLE 1.2

According to the test result, the sample No. 3 has the highest average preference degree score, but partial test subjects react that the three types of yoghourt have stronger sour and astringent feelings, the overall flavor is influenced, and the yoghourt can be better after the sour and astringent tastes are removed. Viscosity data; number 1 is 608cP, number 2 is 710cP, and number 3 is 578 cP.

The following measures can be taken for the unstable phenomena such as whey separation and the like of the product in the embodiment: replacing pectin with clear hydrocolloid with better performance; the final stability of the product is improved by using the compound colloid with better cooperativity. Adjustments are made to remove the acerbity according to the subject's response, and the following measures may be taken: the addition amount of white granulated sugar is increased; the way of adding essence and sweetener is adopted to cover the sour and astringent feeling; adding fruit juice and jam. However, the above measures will certainly increase the cost of the product, so that new ways for improving the product are required.

Example 8: the agar is adopted as one of the stabilizers

The raw material formula is as follows:

91.85% of raw milk, 7% of white granulated sugar, 1% of milk protein powder, 0.1% of agar, 0.05% of pectin and 0.0035% of strain.

1. The method comprises the following steps:

2. Description of the procedure

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally cooling and filling.

In the present example, it was found that the sour and astringent feeling of pectin alone could be improved by using agar instead of a part of pectin, but the addition of agar increased the viscosity of the product greatly, and the viscosity reached 1453cpa, which did not provide a refreshing taste like drinking yoghurt.

Example 9: zero strength agar is used as a single stabilizer

The raw material formula is as follows: 91.85 percent of raw milk, 7 percent of white granulated sugar, 1 percent of milk protein powder, 0.15 percent of zero-strength agar and 0.0035 percent of strain.

1. The method comprises the following steps:

2. Description of the procedure

(2) adding pectin, agar and sugar premix after a period of time, and stirring;

(5) after sterilization, cooling inoculation is carried out;

(7) after cooling, carrying out secondary homogenization on the fermented milk;

(8) and finally cooling and filling.

The drinking yoghurt prepared by independently adding the zero-strength agar is tested in the experimental process, and when the addition amount of the agar enables the yoghurt to have good mouthfeel, the phenomena of whey separation and the like in the center fault of the yoghurt can be found in the stability test; when the addition amount is added, the yoghourt has better stability, has thicker mouthfeel and does not have the refreshing feeling of drinking yoghourt.

The zero-strength agar not only has the general characteristics of agar, but also has the functional characteristics that the common agar cannot replace, such as better water solubility, lower dissolution temperature, lower gel strength, better water retention, favorable absorption by human bodies and the like; has more uniform molecular chain structure and stable product performance. In the invention, the zero-strength agar has shorter and more uniform agar sugar chains after being dissolved in the aqueous solution, more formed double helix structures and double helix molecules of pectin in the aqueous solution form a more dense three-dimensional network structure, and the water retention property is better and more stable.

The invention uses the zero-strength agar and the pectin in a matching way. After a plurality of tests, the addition amounts of the zero-strength agar and the pectin are determined, the drinking yoghurt is prepared for stability observation, no whey separation phenomenon is found (for example, fig. 2 shows the stability observation state of all compound samples for repeated tests, 3 samples from left to right are repeated preparation samples, and are all samples prepared by compounding the zero-strength agar and the pectin according to the optimal proportion), and the score is higher than that of the drinking yoghurt using the pectin and the zero-strength agar alone after the taste test (as shown in tables 2.1-2.2, sample No. 1 corresponds to example 2, sample No. 2 corresponds to example 7, and sample No. 3 corresponds to example 9).

TABLE 2.1

TABLE 2.2

According to the test results, the average preference degree score of the sample in the example 2 is the highest, the sample in the example 2 is a compound sample of zero-degree agar and pectin, the sample in the example 7 is a sample for pure use of pectin, the sample in the example 9 is a sample for single use of zero-degree agar, and the three samples have the same formula process except for the stabilizer. Viscosity data: example 2 sample 625cP, example 7 sample 598cP, example 9 sample 685 cP.

The low-temperature drinking yoghurt is prepared by using the zero-strength agar to replace part of pectin as a yoghurt stabilizer, so that the drinking yoghurt can keep good stability after the protein content is increased, and has fresh, cool and fine mouthfeel without astringent taste.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. A preparation method of drinking yoghurt is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

(1) heating raw milk, adding a first premix, and stirring;

(2) adding the second premix and stirring;

(3) homogenizing, sterilizing, cooling, inoculating, and fermenting until acidity reaches 70-75 ° T;

(4) and (5) demulsifying and cooling, and then carrying out secondary homogenization.

2. The method of making a drinking yoghurt as claimed in claim 1, characterized in that: in the step (1), the raw milk is heated circularly at 60 ℃ for 30min, the stirring time is 20min, the homogenization in the step (3) is carried out at 65-70 ℃ and under 15-18MPa, the sterilization is pasteurization at 95 ℃ for 5min, the fermentation temperature is 43 ℃ and the fermentation time is 5-6h, and the homogenization in the step (4) is carried out at 20-25 ℃ and under 6-8 MPa.

3. A method of preparing a drinking yoghurt as claimed in claim 1 or 2, characterized in that: and refrigerating and after-ripening are required after fermentation, wherein the storage temperature in refrigerating is 2-4 ℃, and the after-ripening time is at least 12 h.

4. A method of preparing a drinking yoghurt as claimed in claim 3, characterized in that: the first premix is a premix of sugar and milk protein powder; the second premix is a premix of pectin, zero-strength agar and sugar.

5. The method of preparing gas-producing yogurt according to claim 4, wherein: according to the mass fraction, 90-95% of raw milk, 5-8% of white granulated sugar, 0.6-1% of milk protein powder, 0.1-0.15% of zero-strength agar and 0.05-0.1% of pectin.

6. The method of making a drinking yoghurt as claimed in claim 5, characterized in that: 91.8 percent of raw milk, 7 percent of white granulated sugar, 1 percent of milk protein powder, 0.12 percent of zero-strength agar and 0.08 percent of pectin.

7. The method for preparing a drinking yoghurt as claimed in any one of claims 1, 2 and 4 to 6, wherein the method comprises the steps of: the strain of the inoculation is a fermentation strain of YF-L822 type in Kehansen.