Physicochemical, microbiological, and sensory properties of low-lactose yogurt using Streptococcus thermophilus with high β-galactosidase activity.

. The optimal temperature was 42 °C for St. thermophilus to acidify yogurt faster than at other temperatures, but it was effective in hydrolyzing the lactose in the media and yogurt. The LAB population in 37 °C fermented yogurt was higher than in other samples, while the starters St. thermophilus and Lb. bulgaricus with a ratio of 2:1 used lactose more effectively than other sample ratios. The lactose content decreased significantly at 37 °C, where it was approximately 50% hydrolyzed. The acceptability of yogurt as a sensory property was unaffected by relative lower fermentation temperatures (30 and 37 °C), despite using different ratios of St. thermophilus and Lb. bulgaricus as starter cultures. This article is protected by copyright. All rights reserved.