阅读说明：本技术 一种具有抗氧化活性的肉桂功能酸奶及其制备方法 (Cinnamon functional yogurt with antioxidant activity and preparation method thereof ) 是由 张笮晦 陈耿 覃梦结 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种具有抗氧化活性的肉桂功能酸奶,按质量百分比计,由以下的原料组成：牛奶77～92％；糖4～9％；肉桂粗多酚0.02～0.10％；发酵剂0.1～1.0％；水余量；其制备方法,包括以下步骤：(1)向牛奶中添加肉桂粗多酚、糖和纯净水,搅拌混合,得到原料乳；(2)将所述原料乳进行加热、均质、加入发酵剂、发酵,形成发酵酸奶,然后冷藏。本发明将肉桂粗多酚与纯牛奶混合发酵,使酸奶既具有肉桂的特殊风味,又具有较强的抗氧化活性,在使酸奶风味多元的同时也提升了酸奶的抗氧化功能。(The invention discloses cinnamon functional yoghourt with antioxidant activity, which consists of the following raw materials in percentage by mass: 77-92% of milk; 4-9% of sugar; 0.02-0.10% of cinnamon crude polyphenol; 0.1-1.0% of a leavening agent; the balance of water; the preparation method comprises the following steps: (1) adding cinnamon crude polyphenol, sugar and purified water into milk, and stirring and mixing to obtain raw milk; (2) heating the raw milk, homogenizing, adding a starter, fermenting to form fermented yogurt, and refrigerating. According to the invention, the cinnamon crude polyphenol and the pure milk are mixed and fermented, so that the yoghourt has the special flavor of cinnamon and stronger antioxidant activity, and the antioxidant function of the yoghourt is improved while the yoghourt has multiple flavors.)

1. The cinnamon functional yogurt with the antioxidant activity is characterized by comprising the following raw materials in percentage by mass: 77-92% of milk; 4-9% of sugar; 0.02-0.10% of cinnamon crude polyphenol; 0.1-1.0% of a leavening agent; the balance of water.

2. The cinnamon functional yogurt with antioxidant activity as claimed in claim 1, wherein the cinnamon functional yogurt is composed of the following raw materials by mass percent: 89% of milk; 8% of sugar; 0.04% of cinnamon crude polyphenol; 0.10% of a leavening agent; and 2.86 percent of water.

3. Cinnamon functional yoghurt with antioxidant activity as claimed in claim 1 or 2, characterized in that the milk has milk solids-not-fat not less than 8.1g/100 g.

4. The cinnamon functional yogurt with antioxidant activity as claimed in claim 1 or 2, wherein the cinnamon crude polyphenol is prepared by extracting cinnamon branches and leaves and residues thereof with water, precipitating with ethanol, concentrating filtrate, and drying.

5. The cinnamon functional yogurt with antioxidant activity as claimed in claim 1 or 2, wherein the starter is composed of Lactobacillus bulgaricus and Streptococcus thermophilus in a mass ratio of 1: 1.

6. A method for preparing cinnamon functional yogurt with antioxidant activity according to any one of claims 1 to 5, comprising the following steps:

(1) adding cinnamon crude polyphenol, sugar and purified water into milk, and stirring and mixing to obtain raw milk;

(2) heating the raw milk, homogenizing, adding a starter, fermenting to form fermented yogurt, and refrigerating.

7. The preparation method of cinnamon functional yogurt with antioxidant activity according to claim 6, wherein the heating temperature in step (2) is 85-95 ℃ and the heating time is 10-15 min.

8. The preparation method of cinnamon functional yogurt with antioxidant activity according to claim 6, wherein the homogenization pressure in step (2) is 15-20 Mpa, and the homogenization time is 4-7 min.

9. The preparation method of cinnamon functional yogurt with antioxidant activity according to claim 6, wherein the raw milk is heated to kill the mixed bacteria after homogenization in step (2), and then a starter is added, wherein the fermentation temperature is 40-45 ℃, and the fermentation time is 6-11 hours.

10. The preparation method of cinnamon functional yogurt with antioxidant activity according to claim 6, wherein the refrigeration temperature in step (2) is 1-4 ℃.

Technical Field

The invention belongs to the field of food industry, and particularly relates to cinnamon functional yogurt with antioxidant activity and a preparation method thereof.

Background

Cinnamon (cinnamon cassia Presl), also known as cinnamon, is a traditional plant used as both medicine and food in our country. Cinnamon oil is industrially extracted from cinnamon branches and leaves by a steam distillation method, and the residual oil extraction residue of the cinnamon branches and leaves is generally used as boiler fuel. The cinnamon branch and leaf oil extraction residue contains various traditional Chinese medicine chemical active ingredients such as polysaccharide, polyphenol, flavone and the like, wherein the cinnamon polyphenol has the effects of resisting oxidation, resisting inflammation and immunity, inhibiting cancer cells, protecting nerves and the like, and also plays an active role in reducing oxidative stress and improving insulin sensitivity.

The yoghourt is a popular food which is rich in nutrition and suitable for the old and the young, and the functional yoghourt has more functions due to the addition of certain functional components with special health care functions, so that the yoghourt is a hot point of yoghourt research in recent years. Researches show that the cinnamon extract can enhance the antioxidant activity of the yoghourt when used for fermenting the yoghourt and has influence on both the physicochemical property and the antioxidant property of the fermented milk. And cinnamon-containing yoghurt has high bioavailability after simulated gastrointestinal digestion and is an important source of biologically acceptable polyphenols in the diet.

Disclosure of Invention

The invention aims to provide cinnamon polyphenol functional yogurt with antioxidant activity and a preparation method thereof, so as to develop the utilization of polyphenol active ingredients in cinnamon branch and leaf oil extraction residues in food.

In order to achieve the above object, the present invention is achieved by the following technical solutions.

A cinnamon functional yogurt with antioxidant activity is composed of the following raw materials in percentage by mass: 77-92% of milk; 4-9% of sugar; 0.02-0.10% of cinnamon crude polyphenol; 0.1-1.0% of a leavening agent; the balance of water.

Further, the cinnamon functional yogurt with antioxidant activity is characterized by comprising the following raw materials in percentage by mass: 89% of milk; 8% of sugar; 0.04% of cinnamon crude polyphenol; 0.10% of a leavening agent; and 2.86 percent of water.

Furthermore, the milk solid content of non-fat milk of the milk is more than or equal to 8.1g/100 g.

Furthermore, the cinnamon crude polyphenol is prepared by extracting cinnamon branches and leaves and residues thereof with water, precipitating with ethanol, concentrating filtrate and drying.

Further, the leavening agent consists of lactobacillus bulgaricus and streptococcus thermophilus according to the mass ratio of 1: 1.

The invention also provides a preparation method of the cinnamon functional yoghourt with the antioxidant activity, which comprises the following steps:

(1) adding cinnamon crude polyphenol, sugar and purified water into milk, and stirring and mixing to obtain raw milk;

(2) heating the raw milk, homogenizing, adding a starter, fermenting to form fermented yogurt, and refrigerating.

Further, in the step (2), the heating temperature is 85-95 ℃, and the heating time is 10-15 min.

Further, the homogenizing pressure in the step (2) is 15-20 Mpa, and the homogenizing time is 4-7 min.

Further, heating the raw milk to kill bacteria after homogenization in the step (2), and then adding a fermenting agent, wherein the fermentation temperature is 40-45 ℃, and the fermentation time is 6-11 hours.

Further, the refrigerating temperature in the step (2) is 1-4 ℃.

Compared with the prior art, the invention has the following advantages and technical effects:

1. the invention utilizes the cinnamon crude polyphenol extracted from the cinnamon branches and leaves and the oil extraction residues thereof as the flavor additive of the yoghourt for providing reference for the development and utilization of polyphenol active ingredients in the cinnamon branches and leaves oil extraction residues in food.

2. Compared with the yoghourt without adding the cinnamon coarse polyphenol, the product of the invention not only has the special flavor of cinnamon, but also has stronger antioxidant activity, and the antioxidant function of the yoghourt is improved while the yoghourt flavor is diversified.

3. The optimal formula for preparing the cinnamon functional yoghourt with the antioxidant activity is obtained by optimizing the process of the invention and comprises the following steps: the material consists of the following raw materials in percentage by mass: 89% of milk (the solid of non-fat milk is more than or equal to 8.1g/100 g); 0.04% of cinnamon crude polyphenol; 8% of sugar; 0.10 percent of leaven (consisting of lactobacillus bulgaricus and streptococcus thermophilus according to the mass ratio of 1: 1); 2.86 percent of water, the comprehensive index of the texture of the yoghurt obtained under the formula is optimal, which is beneficial to guiding production, therefore, the optimal formula obtained under the selection of the invention obtains unexpected technical effects, which shows that the yoghurt has outstanding substantive characteristics and remarkable progress and is creative.

Drawings

FIG. 1 is a graph showing the effect of the amount of crude cinnamon polyphenol added on yogurt;

FIG. 2 is a graph showing the effect of white sugar addition on yogurt;

FIG. 3 is a graph of the effect of milk addition on yogurt;

FIG. 4 is a graph showing the effect of starter addition on yogurt;

FIG. 5 is a graph of the effect of fermentation temperature on yogurt;

FIG. 6 is a graph of the effect of fermentation time on yogurt;

FIG. 7 is a flow chart of the preparation process of cinnamon functional yogurt with antioxidant activity according to the present invention;

FIG. 8 is a graph of the change in acidity of a yogurt during storage;

FIG. 9 is a graph showing the change in SOD content in yogurt;

FIG. 10 is a graph showing the change in water retention of yogurt.

Detailed Description

For a better understanding of the present invention, the following examples are given to illustrate, but not to limit the scope of the present invention.

First, sensory evaluation

Sensory evaluation is carried out according to a food sensory evaluation method, and the product is prepared by 10 food hygiene and nutrition professionals to perform sensory evaluation on cinnamon polyphenol yoghourt from the aspects of flavor, color, texture, taste and curd state, wherein the total score is 100. The results were averaged and the scoring criteria are shown in table 1.

TABLE 1 sensory evaluation chart

Second, determination of each operating parameter

1. Determination of raw material ratio

And (3) taking sensory score as reference, setting the total amount of each bottle of yoghourt to be 100mL, fixing the addition of a leavening agent to be 0.15%, fermenting at 42 ℃ for 8h, and inspecting the influence of the addition of crude cinnamon polyphenol, the addition of white granulated sugar and the addition of milk on the sensory score of the yoghourt.

Putting 86% of milk into 6 cups respectively, adding 6% of white granulated sugar into each portion, adding 0.00%, 0.02%, 0.04%, 0.06%, 0.08% and 0.10% of cinnamon crude polyphenol respectively, adding purified water, homogenizing, sterilizing, cooling, adding 0.15% of leaven, wherein the total volume is 100mL, fermenting at 42 ℃ for 8h, and obtaining the influence of the addition amount of the cinnamon crude polyphenol shown in figure 1. As can be seen from fig. 1, when the addition amount of the crude cinnamon polyphenol is in the range of 0.00% to 0.04%, the sensory score is gradually increased, and when the addition amount is 0.04%, the sensory score is the highest value, and at this time, the yogurt has both the milk flavor and the flavor of the cinnamon polyphenol, and after the addition amount of the crude cinnamon polyphenol is 0.04%, the sensory score is correspondingly decreased, so that the optimum addition amount of the crude cinnamon polyphenol is 0.04%.

Putting 86% of milk into 6 cups respectively, adding 0.04% of cinnamon crude polyphenol into each portion, adding 4%, 5%, 6%, 7%, 8% and 9% of white granulated sugar respectively, adding purified water, homogenizing, sterilizing, cooling, adding 0.15% of leaven, wherein the total volume is 100mL, fermenting at 42 ℃ for 8h, and obtaining the influence of the addition amount of the white granulated sugar as shown in figure 2. As can be seen from FIG. 2, when the addition amount of white granulated sugar is in the range of 4% -8%, the sensory score is in an ascending trend, and at 8%, the sour-sweet degree of the yogurt is accepted by most people, and the sensory score is also highest. After 8%, the added white granulated sugar makes the yogurt excessively sweet, and sensory score is correspondingly reduced, so that the optimal addition amount of the white granulated sugar is 8%.

77%, 80%, 83%, 86%, 89% and 92% of milk is respectively put into 6 cups, 8% of white granulated sugar and 0.04% of cinnamon crude polyphenol are added into each portion, purified water is added, after homogenization, sterilization and cooling are carried out, 0.15% of leavening agent is added, the total volume is 100mL, and fermentation is carried out at 42 ℃ for 8 hours, so that the influence of the milk addition amount is obtained as shown in figure 3, the milk flavor in the yoghourt is gradually increased along with the increase of the milk addition amount, the mouthfeel is smooth, the sensory score is gradually increased, when the milk addition amount reaches 89%, the milk flavor and flavor substances in the yoghourt are harmonious, the sensory score reaches the highest, and then the milk addition amount is increased, the milk flavor covers the flavor of flavor substances, the yoghourt is mainly the milk flavor, and the sensory score is decreased, so that the optimal milk addition amount is 89%.

According to the results of the single-factor experiment, the optimization conditions of the cinnamon polyphenol yogurt raw material ratio are as follows: 0.04% of cinnamon crude polyphenol, 8% of white granulated sugar and 89% of milk.

2. Determination of fermentation Process

Taking sensory score as reference, setting the total amount of each bottle of yogurt to be 100mL, fixing the adding amount of crude cinnamon polyphenol, the adding amount of white granulated sugar and the adding amount of milk to be 0.04%, 8% and 89%, and investigating the influence of the adding amount of a leavening agent, fermentation time and fermentation temperature on the sensory score of the cinnamon polyphenol yogurt.

Respectively putting 89% of milk in 6 cups, adding 8% of white granulated sugar and 0.04% of cinnamon crude polyphenol in each portion, adding purified water, homogenizing, sterilizing, cooling, respectively adding 0.05%, 0.10%, 0.15%, 0.20%, 0.25% and 0.30% of a leavening agent, wherein the total volume is 100mL, fermenting at 42 ℃ for 8 hours to obtain the influence of the addition amount of the leavening agent as shown in figure 4, and the influence can be known from figure 4. Under the same temperature and fermentation time, the addition amount of the leavening agent can influence the sour and sweet degree of the yoghourt, so that firstly, the sensory score is increased and the acidity is gradually improved along with the increase of the addition amount of the leavening agent, when the addition amount of the leavening agent is 0.10%, the sour and sweet degree of the yoghourt is moderate at the moment, the sensory score reaches the highest, and then, the mouthfeel of the yoghourt is sour along with the increase of the addition amount of the leavening agent, and the sensory score is reduced, so that the optimal addition amount of the leavening agent is 0.10%.

89% of milk is respectively put into 6 cups, 8% of white granulated sugar and 0.04% of cinnamon crude polyphenol are added into each portion, purified water is added, the milk is homogenized, sterilized and cooled, 0.10% of leavening agent is added, the total volume is 100mL, the fermentation is carried out for 8 hours at 40 ℃, 41 ℃, 42 ℃, 43 ℃, 44 ℃ and 45 ℃ respectively, the influence of the fermentation temperature is obtained as shown in figure 5, as can be seen from figure 5, when the fermentation temperature is in the range of 40-42 ℃, the sensory score is gradually increased along with the increase of the fermentation temperature, when the fermentation temperature reaches 42 ℃, the yogurt is well solidified, has uniform texture and fine taste, the sensory score reaches the highest, and then along with the increase of the fermentation temperature, the yogurt has poor sour and sweet degree, coarse taste and gradually decreased sensory score, so the optimal addition temperature for fermentation is 42 ℃.

89% of milk is respectively placed in 6 cups, 8% of white granulated sugar and 0.04% of cinnamon crude polyphenol are added into each cup, purified water is added, the milk is homogenized, sterilized and cooled, 0.10% of leavening agent is added, the total volume is 100mL, and the milk is fermented for 6h, 7h, 8h, 9h, 10h and 11h at 42 ℃, so that the influence of the fermentation time is shown in figure 6, as can be seen from figure 6, in the fermentation time range of 6-7 h, not only is the sensory score increased, but also the yogurt is more solidified, when the fermentation time reaches 7h, the yogurt surface is smooth and free of bubbles, the sour and sweet degree is better, the mouthfeel is fine and smooth, the sensory score reaches the highest, and then, along with the increase of the fermentation time, the acidity is increased, the proportion of the sour and sweet degree is not proper, the sensory score is gradually reduced, so that the optimal fermentation time is 7 h.

From the results of the single-factor experiment, the optimization conditions of the cinnamon yoghourt fermentation process are as follows: the addition amount of the leaven is 0.10 percent, the fermentation temperature is 42 ℃, and the fermentation time is 7 hours.

Third, specific embodiments

Example 1

A cinnamon functional yogurt with antioxidant activity is composed of the following raw materials (calculated by 1kg of yogurt, namely the total mass of a total fermentation system is 1kg, and the following proportions are mass percentages): 89% of milk (the solid of non-fat milk is more than or equal to 8.1g/100 g); 0.04% of cinnamon crude polyphenol; 8% of sugar; 0.10 percent of leaven (consisting of lactobacillus bulgaricus and streptococcus thermophilus according to the mass ratio of 1: 1); and 2.86 percent of water.

The preparation method of the cinnamon functional yogurt with the antioxidant activity comprises the following steps (see figure 7):

1) preparing raw milk: adding the above quantitative cinnamon crude polyphenol, sugar and water into milk, and mixing well to form raw milk;

2) heating the raw milk obtained in the step 1) to 50 ℃, and homogenizing under the pressure of 15Mpa for 5 min; heating the homogenized material liquid to 90 deg.C, maintaining the temperature for 15min for sterilization, and cooling to below 40 deg.C; adding a leaven, uniformly stirring, and fermenting at 42 ℃ for 7 hours; and then performing sterile subpackage, and finally putting into a refrigeration house at the temperature of 1-4 ℃ for refrigeration to obtain the cinnamon functional yogurt with the antioxidant activity, wherein the sensory score is 87.3.

Example 2

A cinnamon functional yogurt with antioxidant activity is composed of the following raw materials (calculated by 1kg of yogurt, namely the total mass of a total fermentation system is 1kg, and the following proportions are mass percentages): 86% of milk (the solid of non-fat milk is more than or equal to 8.1g/100 g); 0.10 percent of cinnamon crude polyphenol; 6% of sugar; 0.15 percent of leaven (consisting of lactobacillus bulgaricus and streptococcus thermophilus according to the mass ratio of 1: 1); and 7.75 percent of water.

The preparation method of the cinnamon functional yogurt with the antioxidant activity comprises the following steps (see figure 7):

1) preparing raw milk: adding the above quantitative cinnamon crude polyphenol, sugar and water into milk, and mixing well to form raw milk;

2) heating the raw milk obtained in the step 1) to 50 ℃, and homogenizing under the pressure of 15Mpa for 5 min; heating the homogenized material liquid to 90 deg.C, maintaining the temperature for 15min for sterilization, and cooling to below 40 deg.C; adding a leaven, uniformly stirring, and fermenting at 42 ℃ for 8 hours; and then performing sterile subpackage, and finally putting into a refrigeration house at the temperature of 1-4 ℃ for refrigeration to obtain the cinnamon functional yogurt with the antioxidant activity, wherein the sensory score is 84.7.

Example 3

A cinnamon functional yogurt with antioxidant activity is composed of the following raw materials (calculated by 1kg of yogurt, namely the total mass of a total fermentation system is 1kg, and the following proportions are mass percentages): 77% of milk (the solid of non-fat milk is more than or equal to 8.1g/100 g); 0.04% of cinnamon crude polyphenol; 8% of sugar; 0.15 percent of leaven (consisting of lactobacillus bulgaricus and streptococcus thermophilus according to the mass ratio of 1: 1); and (5) 14.81 percent of water.

The preparation method of the cinnamon functional yogurt with the antioxidant activity comprises the following steps (see figure 7:

1) preparing raw milk: adding the above quantitative cinnamon crude polyphenol, sugar and water into milk, and mixing well to form raw milk;

2) heating the raw milk obtained in the step 1) to 50 ℃, and homogenizing under the pressure of 15Mpa for 5 min; heating the homogenized material liquid to 90 deg.C, maintaining the temperature for 15min for sterilization, and cooling to below 40 deg.C; adding a leaven, uniformly stirring, and fermenting at 42 ℃ for 8 hours; and then performing sterile subpackage, and finally putting into a refrigeration house at the temperature of 1-4 ℃ for refrigeration to obtain the cinnamon functional yogurt with the antioxidant activity, wherein the sensory score is 78.6.

Example 4

A cinnamon functional yogurt with antioxidant activity is composed of the following raw materials (calculated by 1kg of yogurt, namely the total mass of a total fermentation system is 1kg, and the following proportions are mass percentages): 89% of milk (the solid of non-fat milk is more than or equal to 8.1g/100 g); 0.04% of cinnamon crude polyphenol; 8% of sugar; 0.10 percent of leaven (consisting of lactobacillus bulgaricus and streptococcus thermophilus according to the mass ratio of 1: 1); and 2.86 percent of water.

The preparation method of the cinnamon functional yogurt with the antioxidant activity comprises the following steps (see figure 7):

1) preparing raw milk: adding the above quantitative cinnamon crude polyphenol, sugar and water into milk, and mixing well to form raw milk;

2) heating the raw milk obtained in the step 1) to 50 ℃, and homogenizing under the pressure of 15Mpa for 5 min; heating the homogenized material liquid to 90 deg.C, maintaining the temperature for 15min for sterilization, and cooling to below 40 deg.C; adding a leaven, uniformly stirring, and fermenting at 40 ℃ for 7 hours; and then performing sterile subpackage, and finally putting into a refrigeration house at the temperature of 1-4 ℃ for refrigeration to obtain the cinnamon functional yogurt with the antioxidant activity, wherein the sensory score is 82.5.

Fourth, quality detection of yoghourt

1. Determination of acidity of yogurt

(1) Preparing the yoghurt by the optimal process (example 1); (2) the yogurt was prepared using essentially the same process as in example 1, except that 0.04% cinnamon crude polyphenol was not added. The 2 processes are adopted to prepare the yoghourt, and then the 2 yoghourt is stored at 4 ℃ for 21 days respectively to measure the acidity. The total acidity of the yogurt was measured by a potentiometric titrator method in GB 5009.239-2016 (measurement of acidity of food), and the result was expressed as Gilnel's degree. As shown in fig. 8, it is seen from fig. 8 that the acidity of the cinnamon polyphenol yogurt changes more gradually in the storage period of 21d, and the acidity of the cinnamon polyphenol yogurt is lower than that of the cinnamon polyphenol yogurt not added from the 11 th d. The cinnamon polyphenol has an inhibiting effect on the growth of lactic acid bacteria, has an influence on the fermentation effect of the yoghourt, inhibits excessive acid production of the yoghourt, delays the after-ripening process of the yoghourt, improves the mouthfeel of the yoghourt and prolongs the shelf life of the yoghourt, so the cinnamon polyphenol yoghourt has smaller acidity than that which is not added in the later storage period.

2. Determination of total number of lactic acid bacteria in yogurt

(1) Preparing the yoghurt by the optimal process (example 1); (2) the yogurt was prepared using essentially the same process as in example 1, except that 0.04% cinnamon crude polyphenol was not added. The 2 processes are adopted to prepare the yoghourt, and then the 2 yoghourt is respectively subjected to the total number of the lactobacillus according to GB 4789.35-2016 (lactic acid bacteria inspection for food microbiology). The total number of lactic acid bacteria is the sum of streptococcus thermophilus and lactobacillus, and the streptococcus thermophilus and the lactobacillus are respectively counted, and the result is shown in table 2, and as can be seen from table 2, the content of the lactobacillus in the yogurt with or without the added cinnamon crude polyphenol is not greatly different, but the content of the streptococcus thermophilus in the cinnamon polyphenol yogurt is lower than that of the yogurt without the added cinnamon crude polyphenol, so that the total content of the lactic acid bacteria in the yogurt without the added cinnamon crude polyphenol is slightly higher than that of the cinnamon polyphenol yogurt.

TABLE 2 Lactobacillus content in yogurt

3. Determination of SOD Activity in yogurt

Superoxide dismutase (SOD) is a substance with antioxidant activity, and the activity of yoghourt added with cinnamon crude polyphenol and the activity of SOD not added with cinnamon crude polyphenol are measured by adopting a T-SOD kit, so that the capability of removing superoxide anion free radicals in a yoghourt sample can be reflected. The SOD content was measured according to the procedure of the kit, and the OD value was measured at 550nm with a full-wavelength multi-functional microplate reader. And calculating the SOD content in the yoghourt according to a formula 1.

(1) Yogurt was prepared using example 1; (2) the yogurt was prepared using essentially the same process as in example 1, except that 0.04% cinnamon crude polyphenol was not added. The yogurt is prepared by adopting the 2 processes, and then the yogurt prepared by adopting the 2 processes is respectively calculated by adopting the formula 1, the experimental result is shown in figure 9, as can be seen from figure 9, the yogurt has certain SOD activity, and the SOD value of the cinnamon polyphenol yogurt is higher than that of the yogurt without the cinnamon polyphenol yogurt in the storage period of 21 d. The added cinnamon crude polyphenol can improve the SOD activity in the yoghourt. SOD can eliminate excessive free radicals, delay aging and improve immunity.

4. Determination of the Water holding Capacity of yogurt

The preparation process of yogurt is substantially the same as that of example 1, except that 0.00%, 0.02%, 0.04%, 0.06%, 0.08%, 0.10% of cinnamon crude polyphenol is added, 10g of 6 yogurt prepared by the above process are weighed and placed in an empty centrifuge tube, A is the mass of the empty centrifuge tube, and A is the mass of the empty centrifuge tube₁Centrifuging at 3000r/min for ten minutes, taking out, standing for ten minutes, discarding supernatant, and adding yogurt into centrifuge tube₂Weighing, carrying out parallel measurement for 3 times, and calculating the water holding capacity of 6 kinds of yogurt according to the following formula 2 to obtain an average value.

Water holding capacity (%) - (A)₂-A)/(A₁-A) × 100% (equation 2)

As shown in fig. 10, it can be seen from fig. 10 that the water holding capacity of the cinnamon polyphenol yogurt is better than that of the yogurt without the cinnamon polyphenol, the water holding capacity reaches the maximum when 0.04% of the cinnamon crude polyphenol is added, and then the water holding capacity is in a certain descending trend with the increase of the added amount of the cinnamon crude polyphenol. The water holding capacity of the yoghourt has great influence on the flavor and the tissue form of the product, and the change of the water holding capacity is influenced by the change of the total solid content and the protein content in the yoghourt. The water holding capacity is increased by adding the cinnamon coarse polyphenol, probably because the cinnamon polyphenol interacts with protein molecules and is tightly combined with a net structure after the yoghurt is fermented and matured, the protein is condensed more tightly and is not easy to break up, the area of combined water is enlarged, the water is kept, the precipitation of whey is reduced, and the effect of improving the tissue form of the yoghurt is achieved.

5. Determination of the texture of yogurt

The preparation process of yogurt is substantially the same as that of example 1 except that crude polyphenol of cinnamon is added in an amount of 0.00%, 0.02%, 0.04%, 0.06%, 0.08%, 0.10%, a probe TA18 is selected, the test distance is 25.00mm, and the probe speed is 2.00mm · s^-1The quality structure of the 6 kinds of yogurt prepared by the above process is determined by the parameter mode. As shown in table 3, as can be seen from table 2, the yogurt containing 0.04% of cinnamon crude polyphenol is optimal in 4 aspects of hardness, viscosity, stickiness and tackiness; the cohesion and elasticity of the yoghurt with the addition amount of 0.02 percent are optimal. Probably because cinnamon polyphenol interacts with casein and is mutually aggregated in the lactic acid bacteria fermentation gelling process, the hardness and the adhesiveness of the yoghourt are improved, excessive yoghourt can be prevented, the internal structure compactness is influenced due to the excessive aggregation volume of the cinnamon polyphenol and protein molecules, and the change of the quality of the yoghourt is caused, but the optimal addition amount of the cinnamon polyphenol is 0.04% by combining the 6 indexes.

TABLE 3 determination of the texture of yogurt

The above description should not be taken as limiting the invention to the embodiments, but rather, as will be apparent to those skilled in the art to which the invention pertains, numerous simplifications or substitutions may be made without departing from the spirit of the invention, which shall be deemed to fall within the scope of the invention as defined by the claims appended hereto.