Abstract

Preparation of Sour Grape (Vitis Vinifera) Beverages and Evaluation of their Storage Stability

Karakala Balaswamy, Pamidighantam Prabhakara Rao, Allani Nagender and Akula Satyanarayana

‘Thompson seedless’ grapes ( Vitis vinifera ) possessing < 13° brix and > 1.0% acidity were used in the preparation of beverages with and without carbonation. Sour grape juice was extracted, bottled and clarified by racking for three months. Palatable blended grape beverages were also prepared using sour grape juice with phalsa / purple grape juice. Process parameters such as quantity of juice, blending proportions and brix / acid ratio for different beverages were optimized. Squashes were prepared by maintaining brix at 45° and acidity 0.75%. Ready- to-serve (RTS) beverages were standardized with brix 15° and acidity 0.14%. The appearance, color and flavor characteristics of sour grape beverages were improved by blending with purple grape juice and phalsa juice at 2:1 and 1:1 ratios respectively. A set of carbonated beverages in the above combinations were also prepared to check their compatibility and acceptability. A marginal rise in total sugars and decrease in acidity were observed in all beverages after 6 months of storage. Sensory evaluation indicated that carbonated beverages were highly acceptable than plain beverages throughout the storage period. Highest scores of 7.4 and 7.5 were recorded for blended grape beverages with purple grape and phalsa juice respectively even after a storage period of 6 months.