Viability of Lactobacillus acidophilus in whole goat milk yogurt during fermentation and storage stages: a predictive modeling study

Abstract

The incorporation of probiotics into fermented milk is beneficial for the consumer's health and it is important to know the viability of these microorganisms in the product, from production to final consumption. This research carried out a predictive study on the behavior of Lactobacillus acidophilus LAFTI L10 probiotic strain during the fermentation and storage stages of whole goat milk yogurt. Selective counts of L. acidophilus were performed with MRS medium added with clindamycin. The primary model of nonlinear regression by Baranyi and Roberts was fit to the experimental data in DMFit 3.5 software and statistically evaluated. The total fermentation time of the yogurt was 6.5 h and 3 logarithmic cycles of probiotic cell growth were observed. During storage, time influenced the concentration of L. acidophilus from the 30th day onwards, maintaining a minimum count that allows the denomination of probiotic yogurt to the product and certifying its quality. The Baranyi and Roberts model fit satisfactorily the experimental data. The results can benefit the dairy industry in the development, optimization, and reliability of their processes for dairy products.