Quality and functional attributes of vacuum-packed yak milk mozzarella cheese as influenced by storage

The fresh m ozzarella cheese was developed from yak milk by using direct acidification method, packaged under vacuum atmosphere and stored at 4 +/- 1 degrees C for 35 days. The effect of storage was evaluated on proximate composition, physicochemical, functional, microbiological and sensory properties of yak milk mozzarella cheese at defined interval. Among the proximate composition, the moisture content of cheese varied from 48.17% at day 0 to 47.00% at the end of storage. As the storage period progressed, a non -significant differences (p>0.05) was observed for the fat, protein and ash content. Storage time significantly (p<0.05) affected the physicochemical properties of cheese sample, including pH, titratable acidity [lactic acid (% by weight)], tyrosine value (<mu>g/g) and total free fatty acids (mu m/g). A significant increase (p<0.05) in functional properties (meltability, free oil formation and stretchablity) of cheese sample was recorded as the storage progressed. A significant increase in the standard plate count and, yeast and mould count was also observed during progress of storage. The sensory evaluation of cheese sample revealed that colour & appearance, flavour, overall acceptability was non -significant (p>0.05) while, body & texture was significant (p<0.05) during storage. Therefore, it was concluded that the vacuum-packed yak milk mozzarella cheese sample could be stored up to 28 days with optimum organoleptic attributes, functional properties and without significant changes.