成熟度对伽师瓜采后蔗糖代谢及后熟甜度的影响

Effects of Maturity on the Sucrose Metabolism and Sweetness of Postharvest Jiashi Melon

【目的】依据成熟度对伽师瓜采后蔗糖代谢及甜度的影响,确定适宜采收成熟度。【方法】采用液相色谱法、分光光度计法,测定常规种伽师瓜3个成熟度果实采后的3种糖组分含量、5种蔗糖代谢酶活性以及甜度的连续变化。【结果】贮期结束时3个成熟度伽师瓜的甜度差异为：成熟度2〉成熟度1〉成熟度3。成熟度2果实的蔗糖含量相对最高、对甜度贡献最大;蔗糖合成酶（SS）、酸性转化酶（AI）、蔗糖磷酸合成酶（SPS）是其采后糖代谢的调控关键酶。【结论】通过采后糖含量、酶活性及甜度的比较,成熟度2（可溶性固形物10%~12%）为伽师瓜适宜贮运的采收成熟度。

[ Objective] The effects of maturity stage on the sucrose metabolism and sweetness of Jiashi melon postharvest were explored to determine the proper maturity stage to harvest for storage and transportation. [ Method 13 sugar contents, sweetness and 5 sucrose metabolism enzymes of conventional variety Jiashi melon harvested in 3 maturity stages were continuous assayed by liquid chromatography and spectrophotometer during storage. [ Result ] At the end of the storage, fruits of 3 maturity stages exhibited a sweetness orders of stage 1 〉 stage 1 〉 stage 3. Sucrose content was the highest component in fruit of stage 2 and made greater contribution to the sweetness. Sucrose synthase （SS）, acid invertase （AI） and sucrose phosphate synthase （SPS） played key roles in postharvest sucrose metabolism. [ Conclusion] Jiashi melon harvested in maturity stage 2 with 10 - 12% SSC was proper for storage and transportation based on the comparison of sugar content, activity and sweetness,