ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Developmental changes of cuticular constituents and their association with ethylene during fruit ripening in Delicious apples

Zhiguo Ju and William J. Bramlage

Postharvest Biology and Technology. Volume 21, Issue 3, February 2001, Pages 257-263.

2001

บทคัดย่อ

Developmental changes in total cuticle and cuticular constituents and their responses to ethylene during fruit ripening were studied using `Delicious' apples. Total chloroform extractable wax and total cutin (including carbohydrate polymers) were 3.1 and 5.4 g m^-2, respectively, in young fruit. They increased during fruit development and reached 14.1 and 24.7 g m^-2 of fruit peel, respectively, at harvest. During postharvest fruit ripening at 20°C, total cutin did not change but total wax increased to 21.5 g m^-2 at 6 weeks. The increase of cuticular wax paralleled the increase of internal ethylene in fruit. Wax was separated by column chromatography into four portions _¯¯ hydrocarbons and wax esters, free alcohols, free fatty acids, and diols. More than half of the diol fraction was ursolic acid. During fruit development, more hydrocarbons and diols than free fatty acids and alcohols accumulated in cuticle. During fruit ripening, all four portions increased, coinciding with the climacteric rise in ethylene, but rates of increase of free fatty acids and alcohols were higher than those of other portions. Preharvest treatment with 220 mg l^-1 aminoethoxyvinylglycine (AVG) inhibited internal ethylene to <0.5 mg l^-1 during 6 weeks at 20°C and no wax accumulation was detected in AVG-treated fruit. Preharvest treatment with 200 mg l^-1 ethephon increased internal ethylene and accelerated wax accumulation compared with controls. Ethephon accelerated and AVG inhibited -farnesene accumulation.