Changes in Quality of Sweetened Nagpur Mandarin Orange Juice in Crown Corked Glass Bottles at Ambient and Refrigerated Conditions

The sweetened, filtered, pasteurized (90 (plus-minus) 2°C), ʹNagpurʹ Mandarin orange (Citrus reticulata Blanco) juice was hot filled without any preservative in sterilized crown corked bottles and processed in boiling water (100 °C, 20 min) before storage under ambient (30 (plus-minus) 5°C) and refrigerated (7-8°C) conditions up to 180 days. Physico-chemical, organoleptic and microbial changes in the juice were studied. Total soluble solids (TSS) and ascorbic acid contents decreased, while pH increased during storage. Titratable acidity declined, but recovered to initial value after 180 days. Non-enzymatic browning (NEB) increased and colour score (L* a* b* values) decreased. Pectin methyl esterase (PME) activity was not detected after pasteurization and during storage up to 180 days. Viscosity decreased after pasteurization and subsequent storage. Limonin content increased after pasteurization and further during storage; the rise being considerably higher at ambient condition than at refrigerated condition. Bacterial and yeast counts were negligible till 180 days at both the storage conditions. Fungal count was negligible at refrigerated condition till 180 days. Sensory qualities viz. body, taste, aroma and colour of the juice were acceptable while bitterness was slight to moderate. Results indicated that ʹNagpurʹ Mandarin juice (sweetened) pasteurized and heat processed can be stored in crown corked glass bottles under refrigerated condition up to 6 months in acceptable condition.