Process Optimization and Flavor Analysis of Xinjiang Characteristic Fermented Milk Tablet

In order to make a fermented milk tablet with rich nutrition and special flavor of Xinjiang Kazak cheese,N-X yeast producing unique flavor and lactic acid bacteria starter were fermented together. The technological conditions of the milk tablet were optimized by setting single factor experiment(fermentation time,fermentation temperature,white sugar addition,inoculation ratio)and L₉(3⁴)orthogonal optimization experiment with sensory evaluation as the index. The results showed that the best technology for flavor milk tablets were:Fermentation temperature 37℃,inoculation ratio(lactic acid bacteria:Yeast)1:3,sugar content 11%,fermentation time 10 h. The milk tablet was pure in color,rich in milk flavor,mellow flavor,moderate in sour and sweet taste,smooth and full. The sensory score was(90.10±1.64)scores. The flavor substances of yeast-added milk tablets and commercially common milk tablets comparison results showed that,the yeast milk tablets were added with 5 and 7 kinds of alcohol and aldehyde flavor substances. The flavor content of ethyl acetate,caproic acid and 2-heptanone was significantly improved,and the flavor of the fermented milk flakes was optimized. Ultimately,according to the national standards,the quality and hygiene indexes of milk tablets were tested. The moisture content was 5.8%,fat content was 12.3%,protein content was 16.7%,total sugar content was 9.1%,number of coliforms was 8.3 MPN/g,the pathogenic bacteria were not detected. All the indicators are in line with the standard,and a fermented milk piece with xinjiang flavor is initially prepared.