阅读说明：本技术 鲜马铃薯在抑制酸乳后酸化中的应用及其酸乳的制备 (Application of fresh potato in inhibiting post-acidification of yogurt and preparation of yogurt ) 是由 焦扬 罗光宏 李兴艳 姚凡 王丽娟 杨生辉 王丹霞 于 2019-12-02 设计创作，主要内容包括：本发明提供了马铃薯在抑制酸乳后酸化中的应用,该马铃薯使用前经过以下处理：取新鲜马铃薯,隔水蒸制30min,趁热去皮,不断击打至马铃薯呈泥状物；本发明采用马铃薯抑制贮藏期乳酸菌的生长,延缓酸奶的后酸化过程,为抑制酸乳后酸化提供另一个方向。(The invention provides an application of potatoes in inhibiting post-acidification of yogurt, wherein the potatoes are treated by the following steps before use: steaming fresh potato in water for 30min, peeling while hot, and beating until the potato is paste; the potato is adopted to inhibit the growth of lactic acid bacteria in the storage period, the post-acidification process of the yoghourt is delayed, and another direction is provided for inhibiting the post-acidification of the yoghourt.)

1. Application of fresh potato in inhibiting post-acidification of yogurt is provided.

2. The use of claim 1, wherein the fresh potatoes are subjected to the following treatments prior to use: steaming fresh potato in water for 30min, peeling while hot, and beating continuously until the fresh potato is paste.

3. The fresh potato yogurt is characterized by containing fresh potato puree, wherein the weight percentage of the fresh potato puree in the yogurt is 0.75-2%.

4. Fresh potato yogurt according to claim 3, characterized by consisting of the following components in weight percent: 62 to 82 percent of fresh milk, 6 to 20 percent of fresh spirulina mud, 0.05 to 0.2 percent of fresh potato hydroxypropyl starch, 0.1 to 0.5 percent of strain, 0.75 to 2 percent of fresh potato mud, 4 to 7 percent of white granulated sugar and the balance of softened water.

5. Fresh potato yogurt according to claim 4, characterized by consisting of the following components in weight percent: 72.28% of fresh milk, 7.23% of fresh spirulina mud, 0.06% of fresh potato hydroxypropyl starch, 0.43% of strain, 0.93% of fresh potato mud, 4.63% of white granulated sugar and the balance of softened water.

6. The fresh potato yogurt of claim 4, wherein the fresh spirulina puree is prepared by: uniformly mixing fresh spirulina liquid and softened water in a volume ratio of 1:1, performing ultrasonic treatment, pausing for 2s every 10s, performing ultrasonic treatment for 20s-30s, heating to 90-95 ℃, preserving heat for 30min, and hermetically cooling to 40 ℃ to obtain fresh spirulina mud.

7. The fresh potato yogurt of claim 6, wherein the fresh spirulina liquid is prepared by: carrying out liquid suspension culture on spirulina bodies, removing impurities from the culture solution, washing with water, and controlling the biomass of the spirulina bodies to be 10 +/-5% to obtain the fresh spirulina liquid.

8. Fresh potato yoghurt as claimed in claim 3, characterized in that the fresh potatoes are treated before use as follows: steaming fresh potato in water for 30min, peeling while hot, and beating continuously until the fresh potato is paste.

9. The fresh potato yogurt as claimed in claim 4, wherein the fresh milk meets the requirements of the quality control specifications NY/T1172-2006 fresh milk.

10. A process for preparing fresh potato yogurt as claimed in claim 4, characterized by comprising the steps of:

1) pretreatment of fresh spirulina mud: mixing fresh spirulina liquid and softened water in a volume ratio of 1:1, performing ultrasonic treatment for 10s and 2s of pause every time, performing ultrasonic treatment for 20s-30s to obtain an ultrasonic extracting solution, heating the ultrasonic extracting solution to 90-95 ℃, preserving heat for 30min, and cooling in a sealed manner to 40 ℃ to obtain fresh spirulina mud;

2) preparing fresh potato paste: steaming fresh potato in water for 30min, peeling while hot, and continuously beating until the fresh potato is paste;

3) preparing strains: culturing directly-thrown lactic acid bacteria powder with 5% softened water sugar solution at 40 deg.C under shaking for 30 min; or culturing directly thrown lactic acid bacteria powder with skimmed milk powder and water at a ratio of 1:12 as culture solution at 37-41 deg.C under 100r/min for 8-12 hr to obtain strain;

4) preheating and homogenizing: mixing the fresh milk with the specified amount, the pretreated fresh potatoes, the white granulated sugar and the fresh potato hydroxypropyl starch, adding the softened water with the specified amount, uniformly mixing to obtain a mixed solution, preheating the mixed solution to 60 +/-5 ℃, and carrying out high-speed shearing homogenization at 1000r/min of 800 plus and minus 5 ℃ for 2-5min, or respectively carrying out homogenization at 150bar and 300bar by adopting pressure homogenization and then uniformly mixing to obtain a homogeneous solution;

5) and (3) sterilization: heating the homogenized solution to 90-95 deg.C, and maintaining the temperature for 20-30 min;

6) inoculation and primary fermentation: cooling the sterilized homogeneous solution to 40-45 deg.C by sealing, mixing with fresh Spirulina mud, adding activated strain, and fermenting at 38-43 deg.C for 5-9 hr to obtain curd;

7) demulsifying: demulsifying the curd for 30-60 s at the speed of 150-250r/min by using a demulsifying machine;

8) and (3) after-fermentation: quickly cooling the curd to 0-4 deg.C, and fermenting for 8-12 hr to obtain fresh Spirulina and fresh potato fermented yogurt.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to application of fresh potatoes in inhibition of post-acidification of yogurt and preparation of the yogurt.

Background

Along with scientific development and social progress, people have stronger health and health consciousness, the pursuit of healthy, reasonable and nutritional diet becomes the mainstream of modern life, the fermented yogurt is well liked by consumers with special flavor, rich nutrition and good physiological function, the yield and sales of the fermented yogurt are gradually increased year by year, the fermented yogurt becomes the first large fermented milk product in China, after the fermented yogurt is normally fermented and solidified, the pH value of the fermented yogurt is continuously reduced due to the fact that thalli still continuously grow and reproduce in the processes of storage, transportation and sale, the residual lactose generated by fermentation generates lactic acid, so that the sour taste which is unacceptable for consumers appears, certain hydrophilic substances and natural preservatives can inhibit mixed bacteria and delay post-acidification in the yogurt can prolong the shelf life of the yogurt are added, and the research on post-acidification inhibition effect of chitosan oligosaccharide to the yogurt is disclosed in 2005 in the food and fermentation industry at 8 th year, the article shows that the chitosan oligosaccharide can obviously inhibit the post-acidification of the yoghourt when the concentration of the chitosan oligosaccharide is 0.25 percent, the article discloses the influence of the pollen polysaccharide on the acidity and the sensory quality in the yoghourt storage in the 10 th stage of 2009 from food research and development, the article shows that the pollen polysaccharide can inhibit the increase of the acidity in the yoghourt storage process, delay the post-acidification process of the yoghourt and prolong the yoghourt storage period by 5-6d, and the article discloses the influence of the tricholoma matsutake polysaccharide on the lactobacillus fermentation and the yoghourt quality in the 2016, the article shows that the growth promotion effect on the lactobacillus is obviously increased when the addition of the tricholoma matsutake polysaccharide is 0.04 percent, the product has a certain inhibiting effect on the lactobacillus acid production and obviously prolongs the post-acidification process of the yoghourt, but the effect of the potato on delaying the post-acidification of the fermented yoghourt is not researched in the prior art.

Disclosure of Invention

In order to fill the blank of the prior art, the invention develops the application of the fresh potato paste in inhibiting the post-acidification of the yogurt through a large number of tests, and provides the application of the fresh potato in inhibiting the post-acidification of the yogurt and the preparation of the yogurt.

The specific technical scheme of the invention is as follows:

the invention provides application of fresh potatoes in inhibiting post-acidification of yogurt and preparation of the yogurt.

Further, the fresh potatoes are treated as follows before use: steaming fresh potato in water for 30min, peeling while hot, and beating until the potato is paste.

Wherein the potato variety is used for processing potato powder with high starch content, such as Atlantic, Kexin, etc.; the invention solves the problem of post-acidification of the yogurt by adding the fresh potato paste into the yogurt.

The invention also provides fresh potato yogurt, which contains the fresh potato puree, and the weight percentage of the fresh potato puree in the yogurt is 0.75-2%.

Further, the fresh potato yogurt also comprises white granulated sugar with the weight percentage of 4-7%.

Further, the yogurt comprises the following components in percentage by weight: 62 to 82 percent of fresh milk, 6 to 20 percent of fresh spirulina mud, 0.05 to 0.2 percent of potato hydroxypropyl starch, 0.1 to 0.5 percent of strain, 0.75 to 2 percent of fresh potato mud, 4 to 7 percent of white granulated sugar and the balance of softened water.

Further, the yogurt comprises the following components in percentage by weight: 72.28% of fresh milk, 7.23% of fresh spirulina paste, 0.06% of fresh potato hydroxypropyl starch, 0.43% of strain, 0.93% of fresh potato paste and 4.63% of white granulated sugar.

Further, the preparation method of the fresh spirulina mud comprises the following steps: uniformly mixing fresh spirulina liquid and softened water in a volume ratio of 1:1, performing ultrasonic treatment, pausing for 2s every 10s, performing ultrasonic treatment for 20s-30s, heating to 90-95 ℃, preserving heat for 30min, and hermetically cooling to 40 ℃ to obtain fresh spirulina mud.

Further, the preparation method of the fresh spirulina liquid comprises the following steps: carrying out liquid suspension culture on spirulina bodies, removing impurities from the culture solution, washing with water, and controlling the biomass of the spirulina bodies to be 10 +/-5% to obtain the fresh spirulina liquid.

Further, the preparation of the fresh mashed potatoes comprises the following steps: steaming fresh potato in water for 30min, peeling while hot, and continuously beating until the potato is paste; and obtaining the fresh mashed potatoes.

Furthermore, the fresh milk meets the requirements of the quality management standard of the raw fresh milk of NY/T1172-2006.

Wherein, the strain can adopt direct-vat-set lactic acid bacteria powder or inclined plane preservation bacteria.

The invention also provides a preparation method of the fresh potato yogurt, which comprises the following steps:

1) pretreatment of fresh spirulina mud: mixing fresh spirulina liquid and softened water in a volume ratio of 1:1, performing ultrasonic treatment for 10s and 2s of pause every time, performing ultrasonic treatment for 20s-30s to obtain an ultrasonic extracting solution, heating the ultrasonic extracting solution to 90-95 ℃, preserving heat for 30min, and cooling in a sealed manner to 40 ℃ to obtain fresh spirulina mud;

2) pretreatment of fresh potatoes: steaming fresh potato in water for 30min, peeling while hot, and continuously beating until the potato is paste;

3) preparing strains: mixing the direct vat set lactobacillus powder and 5% softened water sugar solution in a mass ratio of 1:10, and performing shake culture at 40 ℃ for 30 min; or mixing direct vat set lactic acid bacteria powder with skimmed milk powder and water at a mass ratio of 1:12, and shake culturing at 37-41 deg.C and 100r/min for 8-12h to obtain strain;

4) preheating and homogenizing: mixing the fresh milk with the specified amount, the pretreated fresh potatoes, the white granulated sugar and the potato hydroxypropyl starch, adding the softened water with the specified amount, uniformly mixing to obtain a mixed solution, preheating the mixed solution to 60 +/-5 ℃, and carrying out high-speed shearing homogenization at the speed of 1000r/min of 800 plus and minus 5 ℃ for 2-5min, or respectively carrying out homogenization at 150bar and 300bar by adopting pressure homogenization and then uniformly mixing to obtain a homogeneous solution;

5) and (3) sterilization: heating the homogenized solution to 90-95 deg.C, and maintaining the temperature for 20-30 min;

6) inoculation and primary fermentation: cooling the sterilized homogeneous solution to 40-45 deg.C by sealing, mixing with fresh Spirulina mud, adding strain, and fermenting at 38-43 deg.C for 5-9 hr to obtain curd;

7) and (3) after-fermentation: and (4) quickly cooling the curd to 0-4 ℃, and fermenting for 8-12h to obtain the fresh potato yogurt.

The potato is adopted to inhibit the growth of lactic acid bacteria in the storage period, the post-acidification process of the yoghourt is delayed, and another direction is provided for inhibiting the post-acidification of the yoghourt.

Drawings

FIG. 1 is a bar graph of pH change of fermented yoghurts of each group;

FIG. 2 is a bar graph of acidity changes in fermented yoghurts of groups;

FIG. 3 is a bar graph showing the water yield variation of fermented yoghurts of various groups;

FIG. 4 is a bar graph of the viscosity change of fermented yoghurts of various groups;

FIG. 5 is a bar graph of DPPH radical clearance for various groups of fermented yoghurts;

FIG. 6 is a bar graph of ABTS free radical scavenging rate of each group of fermented yogurt.

Detailed Description