Storage temperature effects on blood orange fruit quality

Orange fruits of two blood varieties (Tarocco and Moro) were stored at 8 degreesC and 22 degreesC for 85 and 106 days, respectively, and analyzed periodically for standard quality parameters (total soluble solids, total acidity, ascorbic acid, juice yield, and rind color) and sensory influencing parameters (anthocyanins, and total and free hydroxycinnamic acids). A decrease in total acidity (TA) and juice yield during storage was observed for both cultivars; total soluble solids (TSS) increased only in the Tarocco oranges stored at 8 degreesC. The increase in TSS observed for Tarocco and the simultaneous decrease in TA in both varieties resulted in a higher maturity index (TSS/TA) for the two cultivars. No loss of vitamin C was noted in Tarocco orange at either temperature, whereas a sharp reduction in vitamin C occurred in the first 50 days of storage for Moro. A significant increase in anthocyanin content was observed in Tarocco and Moro stored at 8 degreesC. Overlong storage induces extensive hydrolysis of hydroxycinnamic derivatives to free acids in Moro orange and these, in turn, could develop the malodorous vinylphenols.