Starter culture influence on the yogurt preservation and safety

Abstract

This study explores the impact of distinct starter cultures on the physicochemical characteristics and microbiological safety of yogurt during refrigerated storage. Yogurt samples were formulated from standardized, pasteurized cow's milk using YF-L812 and MyYo cultures. Both starter cultures contains Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus; additionally, MyYo includes probiotic strains Lactobacillus acidophilus La-5® and Bifidobacterium animalis subsp. lactis BB-12®. Analytical assessments included titratable acidity, pH, lipids, total solids and Enterobacteriaceae counting. The YF-L812 variant demonstrated consistent acidification kinetics and compositional stability over a period of 6 weeks, while the MyYo formulation maintained acceptable parameters for a duration of 4 weeks. The absence of Enterobacteriaceae in all samples complies with the safety standards. The results emphasize the critical role of starter culture selection in modulating post-acidification trends, preserving nutritional and textural attributes, and ensuring microbiological safety. These findings substantiate the efficacy of starter culture selection as a pivotal factor in ensuring the stability and safety of yogurt.