Effect of Different Milk Composition on Physico-Chemical Characteristics of Set Type Yoghurt.

The gross composition of milk may affect the textural, compositional and microbiological properties of yoghurt. Sahiwal, Holstein Friesian milk procured from Dairy Animal Training and Research Center, B-block University of Veterinary and Animal Sciences, Pattoki and Nili Ravi buffalo milk procured from Nili Ravi buffalo Research Institute (BRI), Pattoki. All other ingredients purchased from Sigma Aldrich Germany through local suppliers. Milk was standardized to 15% total solids with 3.5% fat. Skim Milk Powder (SMP) was used for the standardization of the yogurt. Milk was pasteurized at 82oC for 5 minutes and cool down to 43℃ and at this temperature starter culture was added. Yogurt batch incubated at 43℃ for 3 to 3.5 h. During this period pH was monitored regularly and as the pH drops to 4.6, the batch was shifted to blast chilling at 1-2℃ and then stored at 4℃. Sensory evaluation of all yogurt samples was carried out on a 9-point hedonic scale. All the tests were carried out on day 0, 7, 14 and 21. The collected data was investigated through ANOVA technique under complete randomized design (CRD) using SAS 9.1 software. The results showed that yoghurt made from Nili Ravi buffalo milk (T_o) showed a significant (p= 0.5) overall acceptability as compared to other treatments. Yoghurt made from Nili Ravi buffalo milk (To) were followed by T₃, T₄, T₁ and T₅ respectively. The Nili Ravi buffalo milk showed higher acceptability to the consumers. [ABSTRACT FROM AUTHOR]