Physiological And Biochemical Mechanism Of Browning Development Induced By Low Temperature In Chinese Olive Fruit

Chinese olive [Canarium album (Lour.) Raeusch] is an evergreen tree of the Burseraceae family that is indigenous to the subtropics of southern China. Chinese olive is grown commercially in many countries, such as China, Vietnam, Thailand, Cambodia, Philippines and Indonisia. China is the largest country of Chinese olive production, and has developed rapidly in the past decade. Fujian, Guandong, Guangxi, Taiwan produce most of the fruits in China. The major factors reducing the storage life and marketability of Chinese olive fruit are discoloration, physiological diseases such as the loss of moisture, wilting, browning by senescence and chilling injury, and pathological diseases caused by pathogenic fungi such as Penicillium sp. and Alternaria sp. Low temperature storage is the most effective means to prolong the shelf-life of Chinese olive fruit. But Chinese olive fruits are sensitive to low temperatures, the fruits are injured after a period of exposure to chilling temperatures below 6℃. Chilling injury symptoms such as surface hollow, surface lesions, water-soaking, surface and internal discoloration (browning) at chilling injury temperature (below 6℃) were occurred. The materials of this experiment were Chinese olive [Canarium album (Lour.) Raeusch cv. Tangxian], which is a major and famous cultivar in Fujian Province. Changes of physiology, biochemistry and cell ultrastructure of Chinese olive fruit duing storage at optimum temperature (8℃ ) and chilling temperature (at 4℃), and observation of chilling injury symptpms development were conducted in this paper. The results were as follows:1. The contents of chlorophyl decrease when Chinese olive stored under 4℃ or 8℃, and the decline trends of the contents of chlorophyll between two temperature are significant (P>0.01). Low temperature stress cause the degration of chlorophyl.The structure of chlorophyll is destored under 4℃. The correlation analysis between the content of chlorophyl and the content of MDA, browning index, the rate of rotten...