| Abstract | Buffalos’ milk was standardized to 3% fat, heated at 90?C for 15 min.., cooled to 42?C, fortified with 50, 100 or 150 mg/l of ascorbic acid (vitamin. C) and inoculated with 3% of a mixed culture of Zabady (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus) and Bifidobacterium bifidum (1:1w/w). The effect of vitamin C on the viability of the culture strains and some chemical and organoleptic properties of the resultant fermented milk product were investigated during 8 days of cold storage at 5?C±2. All fresh modified zabady added with vitamin C resulted in higher acidity than the control sample however the addition of vitamin C by 150 mg/kg milk was more effective in reducing the pH value during storage period than the other treatment. There was a slight effect of vitamin C on the production of total volatile fatty acids (TVFA) and acetaldehyde during storage period. The maximum L. bulgaricus, S. thermophilus and B. bifidum counts were found with 50 mg ascorbic acid after 4 days of storage followed by a gradual reduction to the end of storage period. The addition of vitamin C to the cultured milk products increased the viability of B. bifidum throughout storage period. The highest sensory scores that were comparable to the control were obtained by the addition of 50 mg of vitamin C /kg of fermented milk however increasing vitamin C to 100 or 150 mg /kg extremely lowered the sensory properties of the resultant product. |