Effect of storage conditions on microbiological and physicochemical parameters of cloudy apple juice concentrate

Abstract

The effects on microbiological parameters of minimally pasteurized cloudy apple juice concentrate obtained in a pilot scale from two apple varieties, and their changes with storage time and temperature were investigated. The juice obtained from Red Delicious apples showed an adequate biological stability for import and export market for storage at −8.5 and −20°C during a period of three months. The preservation of samples at −20 and −8.5°C limited to acceptable values the growth of molds and yeasts during the first two months in the case of juice obtained from Granny Smith apples. Neither lactic acid nor thermo acidophilic bacteria were isolated from the samples in all storage conditions. No noticeable differences in pH and soluble solids content were observed among storage times and temperatures. Turbidity increased slightly with storage time. Viscosity decreased substantially during storage at 2°C. Color was stable for all storage conditions evaluated.