บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Effects of Pro-long coating on changes in colour and enzyme activity of postharvest litchi fruit.

Zhang DongLin; Chen Fang; Liu ShuXian; Li YueBiao; Jiang YueMing; Guo JunYan; Quantick, P. C.; Warren, P. J.;

Journal of Tropical and Subtropical Botany Year: 1997 Vol: 5 Issue: 2 Pages: 54-60 Ref: 19 ref.

1997

บทคัดย่อ

Effects of Pro-long coating on changes in colour and enzyme activity of postharvest litchi fruit.

The effects of Pro-Long coating (1.5 or 2.5%) [sucrose esters] on litchi cv. Huaizhi fruit browning during storage at 4 deg C were investigated. The Hunter L and b values in both control and treated fruits decreased continuously with storage time, indicating that the peel became darker and had less yellow characteristics. The Hunter L and b values in the control decreased faster than those in treated fruits. The Hunter a values in both control and treated fruits were relatively stable during the first 20 days of storage and then significantly decreased during the remaining days, implying that stored litchi fruits maintained basically red characteristics during the first 20 days of storage and then became less red, corresponding to the changes in contents of anthocyanins, flavonoids and total phenolics. Hunter a values in the control decreased faster than those in treated fruits after the 21st day of storage. These changes correspond to a visible change to dark red and brown during storage, and c

hanges in polyphenol oxidase (PPO) [catechol oxidase] and peroxidase (POD), which indicate that polyphenol oxidase plays a definite role in postharvest browning, and that peroxidase is partially involved in the browning process. The increase in POD activities of treated fruits was slower than that of the control, and the peaks in PPO activities of treated fruits were delayed slightly compared with that of the control. There was no significant difference between treatment with Pro-long at 1.5% and 2.5%. It is suggested that the application of Pro-long coating to litchi fruits partially inhibits PPO and POD activities, and influences the breakdown of anthocyanin and the changes in contents of flavonoid and total phenolics, thereby delaying the browning process.