Abstract:

Orange juices derived from 3 orange cultivars were stored at 4 ℃ for 12 weeks, and their color, carotenoids and vitamin C contents were determined at intervals of 2 weeks. Color changes of the orange juices and their possible relationships with the changes of carotenoids and ascorbic acid contents were investigated. Results showed that during storage, CIE1976 a* value (redgreen) and OJ value decreased and CIE1976 L* value (brightness), b* value (yellow-blue), C* and Hue values increased, and overall color change (ΔE*) increased significantly (P ＜ 0.05). Simultaneously, the content of carotenoids and vitamin C decreased and browning index increased. The color of orange juice was significantly positively correlated with the content of carotenoids and vitamin C, and significantly negatively correlated with the browning index. From the viewpoint of color, the expiration time of the orange juices is 7－9 weeks.

Key words: orange juice, color change, refrigerated storage, carotenoids, VC