青脆李采后糖积累及代谢相关酶活性变化

Changes in Postharvest Sugar Accumulation and Metabolism-related Enzyme Activities of Green Crisp Plum

通过分析青脆李果实采摘后在贮藏过程中的糖分组成变化及相关酶活性的变化,研究青脆李采后6种糖的积累情况和14种糖代谢相关酶的变化情况.结果表明:青脆李成熟果实中果胶质量分数最高;其次是蔗糖,两种糖质量分数超过总糖质量分数的60%;淀粉和果糖质量分数接近,各占总糖的12.81%和13.31%;葡萄糖质量分数稍低,占8.89%;质量分数最低的可溶性糖为山梨醇,仅占0.58%.果胶酶中对果胶起主要分解作用的是多聚半乳糖醛酸酶(PG);对可溶性糖的积累转化起主要作用的是可溶性酸性转化酶(S-AI)、蔗糖合成酶分解方向(SS-Ⅰ)和α-淀粉酶,同时还与中性转化酶(NI)密切相关.

The accumulation of six sugars and the changes of fourteen enzymes related to sugar metabolism in green crisp plum fruits were studied by analyzing the changes of sugar composition and related enzyme activities during storage after harvesting.The results showed that the highest pectin content was found in the mature fruits of green crisp plums,followed by sucrose,with the content of two sugars exceeding 60%of the total sugar content.The contents of starch and fructose were close,each accounting for about 12.81%and 13.31%of the total sugars.Glucose content is slightly lower,accounting for about 8.89%,and the lowest soluble sugar is sorbitol,containing only about 0.58%.The pectinase that plays a major role in the decomposition of pectin is polygalacturonase(PG).The main role in the accumulation and conversion of soluble sugars is played by soluble acid convertase(S-AI),sucrose synthase catabolic direction(SS-Ⅰ)andα-amylase,and also closely related to neutral convertase(NI).