EFFECTS OF POSTHARVEST STORAGE TEMPERATURES ON CAROTENOID CONTENT OF LOQUAT FRUITS

In this study, qualitative and quantitative analyses of carotenoid contents were conducted in loquat fruit flesh (Eriobotrya japonica Lindl. ‘Zaozhong No. 6’) to explore the effect of storage temperatures on carotenoid accumulation. The results showed that there was a rapid accumulation of lutein, β-cryptoxanthin and β-carotene in loquat fruits when stored at room temperature, and their concentrations peaked at the 12th d. This was followed by a sharp drop resulting from high decay rates. However, the carotenoid content in fruits stored at room temperature were consistently higher than those at 4 and 8°C. The contents of lutein, β-cryptoxanthin and β-carotene in loquat fruits stored at 8°C and room temperature showed an “up-down” pattern during storage, but their peak times were different. The content of β-cryptoxanthin decreased significantly at the late storage stage, and contents of lutein and β-cryptoxanthin gradually decreased with storage time and did not contribute to the accumulation when stored at 4°C. Overall, the contents of lutein, β-cryptoxanthin and β-carotene in loquat fruits stored at 4°C were lower than those at 8°C. Therefore, the lower the storage temperature, the less accumulation of the pulp carotenoids. A low temperature or a long storage time was not beneficial to the accumulation of carotenoids, but the high storage temperature led to a high decay rate. After a comprehensive evaluation of the commodity value of loquat fruit stored at different temperatures, we concluded that 8°C was the optimum temperature for maintaining carotenoid level during long-term storage of loquat fruits.