Physiochemical, nutritional, microbial and sensory attributes of pineapplecarrot-ginger beverage

A functional beverage was prepared from pineapple, carrot and ginger to form a refreshing drink. Three independent variables were used to prepare the beverage using Box-Behnken Design Response Surface Methodology (RSM): pineapple-to-carrot juice ratio (75/25-90/ 10), fibre size distribution (0.6-1.2 mm) and ginger concentration (2-5%). The levels of independent variables were optimized considering total soluble solids, pH, beta-carotene, and sensory attributes as responses. The optimized beverage was obtained at pineapple-tocarrot juice ratio, fibre size distribution and ginger concentration of 80/20, 0.6 mm and 3% respectively. The optimized beverage was kept at -24, -10 and 4 oC for 40 days to study the effect of storage on physicochemical, nutritional, microbial load and sensory attributes of the drink. There were significant changes in ascorbic acid, beta-carotene, total antioxidant activity, total soluble solids, titratable acidity and pH while no significant changes were observed in total phenolic content at the various storage temperatures. Regarding microbial loads, freezing significantly reduced total plate count while exponential growth occurred in the beverage stored at 4 oC. The results validate the fact that frozen storage of fresh beverage slows down quality changes in fresh fruits-veges drink and as a result improve the functionality of the beverage and hence should be considered by the fruit juice industry.