Optimization and Extension of Shelf Life Of Quark - A type of Yoghurt.

Quark was prepared from cow milk by the optimization of different parameters like concentration of rennet, sugar percentage and flavor types. The rennet concentration used for optimization were 0.00139 %, 0.00234 %, 0.00278 % and 0.00468 %. Among these in terms of acidity, texture, flavor and appearance 0.00234 percent rennet was found significantly best product. The concentration of sugar in quark was varied in different proportion viz. 2, 4 and 5 %, among these 4 % was ranked best with respect to sensory properties. For the optimization of flavor, two flavors (pineapple and vanilla) was used along with orange red color and without color for quark preparation, among them vanilla with no color added sample was preferred significantly. The high quality life (HQL) of the optimized product was 45 days in deep frozen condition (-20oC), 6 days in refrigerated condition (-4oC). Even though, the product remained acceptable up to 2 days at room temperature (33 ± 2oC) and up to 15 days in refrigerated conditions.