Effects Of Pleurotus Eryngii Polysaccharides On The Quality Of Fermented Milk

More and more studies have proved the functionality of Pleurotus eryngii(P.eryngii)polysaccharide.Finding an appropriate carrier to bring P.eryngii polysaccharide into the human body is one of the important ways to develop the functionality of P.eryngii polysaccharide.Fermented milk has become a popular food in the current consumer market because of its smooth taste and rich taste.Adding P.eryngii polysaccharide to fermented milk makes it possible for people to obtain the function of P.eryngii polysaccharide while drinking fermented milk,which is of great significance.For this reason,this study obtained P.eryngii polysaccharides base on the protocol in our lab in the early stage,and added them to the fresh milk with different ratio for fermentation,and evaluated the effect of P.eryngii polysaccharide on the quality of fermented milk,in order to better promote the development and utilization of P.eryngii.In this study,P.eryngii polysaccharides were extracted according to the previous method in our lab,and the components of the extracted polysaccharides were analyzed,Then different amounts of polysaccharides were added to the fresh milk,and different fermentation time and sugar added were set.The p H,acidity,and viscosity of the fermented milk during the whole fermentation process were measured,and the effects of polysaccharides,added on the texture of the fermented milk and the number of viable starter was evaluated:The conventional nutrient composition,water holding capacity and water holding capacity of the optimized P.eryngii polysaccharide fermented milk were evaluated.The fermented milk without adding P.eryngii polysaccharides was used as control.The number of viable starter in the fermented milk was determined through a simulated gastrointestinal experiment.Finally,the quality of P.eryngii polysaccharide fermented milk during the 21 d storage period was analyzed,including p H,acidity,water holding capacity,number of viable starter cells,and texture changes,and the sensory characteristics were evaluated by electronic nose and electronic tongue.The results were as follows: the total sugar content of P.eryngii polysaccharide was about 66.42%,and followed by ash,moisture,fat and protein.All fermented milk added with P.eryngii polysaccharide had lower p H,higher acidity and higher viscosity than those of the blank group during the middle and late stages of fermentation.When the addition amount of P.eryngii polysaccharide was 0.12%(mass volume fraction),the number of viable starter in fermented milk was the highest.After a single factor and response surface experiment,the optimal process formula was finally determined to be0.12%(w/v)of P.eryngii polysaccharide,5.5 h of fermentation time and 7% of white sugar.The conventional nutrient analysis of the P.eryngii polysaccharide fermented milk showed that the protein content,total solid,fat,content of the ash P.eryngii polysaccharide contained fermented milk was 3.12%,21.07%,3.26% and 7.23%,the water holding capacity was 84.93%.For the blank control fermented milk,the quality change analysis of the P.eryngii polysaccharide fermented milk during the 21 d storage period revealed that the addition of P.eryngii polysaccharide made the degree of postacidification relatively higher in the later stage,but it was better than the blank control in terms of water holding capacity,and the polysaccharides could also has a certain protective effect on starter.In terms of texture,polysaccharides could also maintain the hardness and viscosity of fermented milk.Electronic nose analysis showed that only polysaccharide fermented milk storage for 21 d and blank fermented milk storage for 14 d had a big difference,and there is no significant difference in the remaining groups.After electronic tongue analysis,it was found that there were differences in sourness,bitterness and bitterness aftertaste,and the other flavors were not different in the analysis of fermented milk in each group.This experiment provides data support for the application of P.eryngii polysaccharide in fermented milk,and new ideas for the deep development of fortified fermented milk.