Ali Jasem Dardar ^1*

¹ Department of Food Engineering, Faculty of Chemical and Petroleum Engineering, Homs, Syria.

(*Corresponding author: Ali Jasem Dardar, Email:  alidrdr2019@gmail.com, mob.: 0991075595)

Received: 13/ 1/ 2025      Accepted: 23/ 4/ 2025

Abstract

The study was conducted to study the effect of adding different proportions of rice milk to the preparation of yogurt from cow’s milk. 100% cow’s milk was used as a control, in addition to treatments of cow’s milk to which rice milk was added at different proportions (25%, 50%, and 75%). Fermentation was performed using a starter culture consisting of two strains of lactic acid bacteria: Lactobacillus bulgaricus and Streptococcus thermophiles, with the latter added at 2% and 3%. Fermentation was carried out at 45°C and continued until a pH of 4.6 was reached. The results showed that the concentration of total solids, fat, total protein, ash and acidity in rice milk were lower than those in cow’s milk, and that the fermentation time was shorter and the total acidity was higher in cow’s milk than in the treatments with added rice milk. The titratable acidity in treatments H, I and J was (0.77, 0.75 and 0.62) respectively, while in the control (0.83). It was shown that the addition of 50% rice milk had good sensory characteristics in the final product. Not only were lactic acid bacteria able to grow in rice milk, but their numbers and viability were also higher than in cow’s milk. Moreover, mixing rice milk with cow’s milk increased this effect.

Keywords: cow’s milk, rice milk, lactic fermentation, yogurt.

 Full paper in Arabic: PDF