Assessment of probiotic and sensory properties of dahi and yoghurt prepared using bulk freeze-dried cultures in buffalo milk

Fermented milk products are part of the diet in many parts of the world and are consumed on a regular basis. Enhancing the nutritional and therapeutic properties of traditional fermented milks can improve the health and physiology of consumers. In the present study, dahi and yoghurt were prepared using buffalo milk. Bulk freeze-dried cultures of dahi and yoghurt, either with or without supplementation of Bifidobacterium bifidum I and Lactobacillus acidophilus R, were used to prepare these products. Probiotic properties such as antimicrobial activity in vitro, effect on body weight and serum cholesterol level in albino rats, and sensory properties of the products were evaluated. Among the products tested, probiotic yoghurt showed very strong inhibition (> 16 mm diameter) against all the food-borne pathogens tested. Supplementation of probiotic cultures helped to improve the body weight of albino rats (Wister) after 30 days of feeding, with a weight gain of 123.33 and 129.33 g with probiotic yogurt and probiotic dahi, respectively. The serum cholesterol level of these rats decreased gradually, with a significant reduction of 2.63, 4.1 and 4.68 mg/100 ml at the end of 30 days in rats fed with yoghurt, probiotic dahi and probiotic yoghurt, respectively, indicating the hypocholesterolaemic effect of the probiotic cultures. No significant difference in sensory scores of dahi and yoghurt was observed with the supplementation of probiotic cultures. Thus, the present study indicated the probiotic potential of dahi and yoghurt prepared using selected probiotic strains.