Detection Of Probiotic Diversity And Shelf-life Prediction Model Establishment Of Yogurt

Yogurt has become the most popular drink for consumers because of good-tasting and the lactic acid bacteria plays an important role in promoting human health.However,the issue that the real kinds of lactic acid bacteria in yogurt and the labeling kinds are consistent or not which needs to be discussed,so firstly,Illumina depth sequencing technology was used to identify the diversity of lactic acid bacteria in yogurt.In addition,yogurt has a short shelf life owing to the active lactic acid bacteria,so how to accurately determine the shelf life of yogurt is another important problem in yogurt industry.Therefore,in the later stage of this research,the real-time variation of the main parameters of yogurt in different storage temperatures were monitored in accelerated destructive and temperature fluctuation experiment,then Arrihenus model was conducted on shelf-life prediction.The experimental result indicated:(1)Although the labeling of lactic acid bacteria is variety,but the results showed that the bacteria of yogurt are highly similar and streptococcus take a dominant position.At the same time,it was found that some yogurt labels didn't match the analysis results well.The lactic acid bacteria in yogurt which was constituted by Streptococcus(87.1%),Lactobacillus(10.3%),and Lactococcus(0.3%).(2)During the storage experiment,the lactic acid bacteria count and total diacetyl content increased at first and then decreased with the time,the acidity increased gradually with the storage period,PH,viscosity and sensory score were decreased,and the temperature had a great impact on the above six parameters.The temperature fluctuation test showed that even transient temperature fluctuations can affect the quality of the yogurt greatly during the storage period.(3)According to the variation of parameters under different storage temperatures,shelf-life prediction models were built for three samples,for sample 1,the prediction shelf-life is 15.5 days;for sample 2,the prediction shelf-life is 19 days;and for sample 3,the prediction shelf-life is 16.5 days which indicated that the shelf-life prediction results were reliable and effective.