Studies On The Process Of Fermentation With Walnut And Milk With Fructooligosaccharide

In this paper, a new walnut product, fermented mixture (walnut and milk) with fructooligosaccharide, was studied. The effect of adding fructooligosaccharide to the mixture on the acidity, the pH value and the Lactic acid bacteria was first discussed, and Lactic acid bacteria were acclimated. In addition, the temperature and pH value during grinding, and the best formula of product, were discussed respectively.From the results of test with different fructooligosaccharide and different additive amount of Lactic acid bacteria, the best additive amount of fructooligosaccharide was 4%. During the fermentation of yogurt for 24 hours at 40℃, acidity went up and pH value went down in FOS group sucrose group and CK(control group) with time, but changes at Lactic acid bacteria counts were different from them, which the counts increased before l0h and decreased slowly thereafter. During the storage of yogurt, acidity rose, pH value dropped, and Lactic acid bacteria counts fell synchronously in FOS sucrose and CK groups with storage time. In conclusion, 4%fructooligosaccharide didn't affect the changes of acidity. pH value and Lactic acid bacteria.According to the acclimation of culture, gradual increase acclimation was adopted because of its more short time and better effect compared with alternant method in this study.During the process of fermentation with walnut and milk with fructooligosaccharide, the quadratic rotation design was applied to study temperature and pH value during grinding and the additive amount of milk, sucrose and emulsifying agent The conclusion show: during the grinding, the dissolution ratio of walnut protein could reach to 80.5430%, the highest value, at 77.69℃ and pH7.26, moreover, the effect of these two factors on dissolution ratio of walnut protein was very remarkable (P<0.01). Their interaction was remarkable (P<0.05); milk and sucrose had very remarkable effect (P<0.01), and emulsifying agent had remarkable effect (P<0.05), but the interaction among three factors wasn't remarkable, in addition, the most appropriate formula of product was: walnut milk 57.7%, milk 42.3%, sucrose 7.2%, fructooligosaccharide 4%, emulsifying agent 0.33%, culture 3%.