Physico-chemical and Sensory Properties of Yogurt Processed from Cow's Milk and Soymilk

By: Tahar Amrouche  

Fermented soymilk was reported to contain no lactose or cholesterol, and its proteins have a greater antioxidative ability in preventing lipid oxidation, compared to casein. In this study, yogurt was processed by inoculation of cow's milk and soymilk used alone and in combination (ratio 1/1 v/v) with freeze-dried culture of Lactobacillus bulgaricus and Streptococcus thermophilus.Three samples from each processed yogurt were evaluated for physico-chemical and organoleptic properties using a control. Sensory test was carried out by sensory panel testing three yogurts prepared and a commercial yogurt SOUMMAM. Yogurts were scooped into small cups with random 3 digit codes. The pH values of yogurt samples ranged from 4.65±0.03 in cow's milk yogurt, 4.60±0.05 in soymilk yogurt, and 4.64± 0.01 in the mix. Soymilk yogurt was low in Dornic acidity (81.66±1°D). Fat and total dry extract were highest in cow's milk yogurt: 31±1 g/l and 106.6±0.2 g/l, respectively. There was significant difference (P < 0.05) in the protein content between cow's milk yogurt (3.1±0.2 g/l) and soymilk yogurt (3.47±0.01 g/l). The results indicate that the addition of soymilk to cow’s milk improved the physicochemical properties as well as sensory characteristics of yogurt, resulting in enhanced health-benefit ingredients and consumers’ preferences. Soymilk yogurt alone or in combination with cow’s milk yogurt can be adopted as substitute to cow's milk yogurt especially by the low income earners due to its cheaper raw materials, and as protein supplement at household level.

Sensory Properties, Yogurt
Food, Nutrition, and Health
Poster/Exhibit Session

Tahar Amrouche

Lecturer, Agronomy, M. Mammeri University, Algeria