The Development Nd Functional Characteristics Of Blueberry Probiotics Mousse

Mousse is a kind of low-temperature dairy dessert suitable for adding probiotics,and it is a key to improve the activity of probiotic during low-temperature storage.Blueberries are rich in soluble polysaccharides,phenolic substances and dietary fiber.It has been proved that these phytochemicals not only have the function of prebiotics,but also can increase the number of viable probiotics during storage.Add blueberries to probiotic mousse to develop a probiotic blueberry mousse with good flavor and taste and antioxidant function,which is of great significance for enriching the variety of probiotic foods and enhancing the added value of dairy products.In this research process,the blueberry mousse was taken as the research object,and the supplemental amount of blueberry was determined by studying the fermentation characteristics of L.plantarum S7 in blueberry fermented milk.The effects of different blueberry addition methods on mousse quality were studied to select the optimal addition methods.The basic formula of mousse was optimized to improve its taste and texture,and the stability and functiona]characteristics of probiotics blueberry mousse during storage at 4? were studied.The results of the study are as follows:1.The effects of blueberry addition on the fermentation performance of L.plantarum S7 was studied.Different proportions of blueberry pulp were added to the reconstituted milk for fermentation.The effects of different proportions of blueberry pulp on the coagulation time,viable count,pH and acidity of L.plantarum S7 fermented milk were determined.The effects of blueberry pulp and juice with the same amount on the fermentation performance of L.plantarum S7.The contents of total phenols and anthocyanins in the fermented milk were compared.The results showed that:with the increase of blueberry pulp,the curdling time of fermented milk gradually shortened,and the viable count of L.plantarum S7 increased faster.When the content of blueberry was more than 40%,fermented milk could not coagulate.When the content of blueberry pulp was 30%?40%,the viable count of fermented milk reached the highest value,ranging from 9.75 to 9.76 log CFU/g.The higher the content of blueberry pulp,the lower the pH and the higher the acidity of fermented milk.During the fermentation process,the pH of five groups of fermented milk samples showed a downward trend,and the acidity gradually increased.When 30%blueberry pulp and juice were added,the coagulation time of fermented milk with blueberry pulp was shorter,the pH was lower,and the acidity,total phenols and anthocyanins content were higher.There was no significant difference in the viable number of lactic acid bacteria between the two groups(P>0.05).The content of total phenols and anthocyanins in two groups of fermented milk increased slightly.2.The effects of different adding methods of blueberry on the quality of probiotic mousse were studied.Blueberry pulp and filtered juice were prepared from blueberry respectively,and then added before or after the fermentation of reconstituted milk,and the blueberry probiotic mousse was prepared.The changes of pH,acidity,viable count,sensory quality,texture,volatile flavor compounds,total phenol content,anthocyanin content and antioxidant capacity of mousse in vitro were studied.The results showed that adding blueberry pulp or juice could significantly improve the titratable acidity,viable count,volatile flavor compounds,total phenol content,anthocyanin content and antioxidant activity of probiotic mousse,and reduce its pH,but had no significant effect on sensory quality.The sensory quality,total phenol content and anthocyanin content of mousse with blueberry pulp were higher than those with blueberry juice.The pH of mousse added with blueberry juice or pulp before fermentation was lower than that added after fermentation,and the titratable acidity,viable count,total phenol content,anthocyanin content and antioxidant activity were higher.The quality of mousse added with blueberry pulp before fermentation was the best.Therefore,the mixed fermentation of blueberry pulp and sterilized reconstituted milk was selected as the blueberry adding method of probiotic mousse.3.The formula of blueberry probiotic mousse was optimized.The effects of blueberry,light cream and soft sugar on the sensory quality and texture characteristics of probiotic mousse were studied.The results of response surface analysis showed that the most influential factors on sensory quality were light cream,blueberry and soft sugar.The best formula is that the optimum conditions were 20%blueberry,21.5%light cream,6.5%soft sugar,40%fermented milk,7%milk,3%egg yolk and 2.0%gilding.Under these conditions,the sensory quality of mousse was the best,and the sensory score of mousse was 94.9 which was higher than the predicted score of 94.24.The stability and functional characteristics of blueberry probiotic mousse during storage were studied.The pH,titratable acidity,viable count,texture characteristics,total phenol content,anthocyanin content,antioxidant capacity and the acid and bile salt tolerance of L.plantarum S7 in blueberry probiotic mousse during storage at 4?for 21 days were determined.The results showed that:with the extension of storage time,pH value and viable count of blueberry probiotic mousse decreased,while acidity,hardness and adhesion increased.Adding blueberry can improve the number of viable bacteria,antioxidant capacity and acid and bile salt tolerance of probiotic mousse during storage at 4? for 21 days.Blueberry probiotic mousse added with blueberry fermented milk has higher antioxidant capacity,total phenol content and anthocyanin content than blueberry mousse.During storage,the antioxidant activity of blueberry probiotic mousse was significantly correlated with total phenol content,anthocyanin content and viable count(P<0.05),while the viable count of probiotics was not significantly correlated with total phenol content and anthocyanin content(P>0.05).