PREPARATION OF WHEY BASED PLUM BEVERAGE AND ITS STORAGE QUALITY EVALUATION

Abstract

Whey is the aqueous (serum) protein of the milk. It compromises approximately 20% of the milk protein, albumins and globulins, majority of lactose and the water-soluble nutrients. The disposal of whey is a major problem for the dairy industries which demands simple and economic solutions. The usage of whey to valuable beverages could overcome the issue. Whey-based plum beverage was prepared by blending sweet whey along with plum juice and required amount of sugar utilizing design expert® (v 13) under mixed condition. By varying whey (50-100%) and plum juice (0-50%) seven formulations were obtained (A, B, C, D, E, F and G). Formulated samples were analyzed by sensory evaluation and the beverage sample F with 62.5% whey and 37.5% plum juice was found to be superior. However, sensory parameters of different formulations were significantly affected (p<0.05) by variation of whey and plum juice. The best sample F was selected and it’s chemical and phytochemical compositions were analyzed. It was pasteurized at 90°C for 10 min and stored in pre-sterilized bottles at ambient and refrigerated conditions for 30 days. The effect of storage time and temperature on physicochemical and microbial properties were evaluated. During storage analysis, TSS, pH and reducing sugar increased while acidity and ascorbic acid content decreased with progressing storage time in both storage condition. Similarly, during 30 days storage, total plate count & yeast and mold count were also increased under both storage condition. These changes in refrigerated storage condition were found to be minor in comparison to normal storage condition. From all the analysis, it can be observed that the beverage can be kept fresh for about 30 days without preservatives.