南果梨果实糖、酸变化规律

Dynamic of Sugar and Acid Content in Nanguo Pear

为增进对南果梨果实发育中糖、酸含量变化的了解,对其糖、酸含量进行测定。结果表明,在果实生长发育过程中,总糖含量呈"上升-下降-上升"的趋势;总酸含量呈"下降-上升"趋势;幼果期果实中的糖以山梨醇为主,酸以奎宁酸为主;成熟果实中的糖以果糖为主,酸以柠檬酸和苹果酸为主,成熟时果糖含量占总糖含量的50.9%,柠檬酸和苹果酸含量占总酸含量的75.2%,并且柠檬酸含量超过苹果酸;果实发育前期及中期不含蔗糖,仅在成熟前期出现蔗糖,并且含量一直呈上升趋势,在采收时达到最高峰;淀粉含量呈"上升-平缓-下降"的趋势;果实采收前,总糖、总酸、果糖、柠檬酸及苹果酸含量有一快速上升过程;南果梨糖积累类型属于中间型。

In order to understand the changes about sugar and acid content during fruit development of Nanguo pear,this test of the content of sugar and acid was carried out.The results showed that,during the process of fruit growth and development,the total sugar content appeared the ＂up-down-up＂ trend and the total acid content was the ＂up-down＂ trend.In the young-fruit period,the main type of sugar and acid was sorbitol and quinate respectively.In the mature period,fructose was the main fruit sugar type,and citric acid and malic acid were the main acids.In the mature period,the fructose took up 50.9% of the total sugar and the citric acid and malic acid took up 75.2% of the total acid,and moreover the content of citric acid was more than malic acid;Sucrose was not detected in the early and medium-term stage of fruit development,and it was detected only in pre-mature period and its content was on the rise since then.It reached peak at harvest period;The starch content showed the ＂up-flat-down＂ trend.In the pre-harvest period,the contents of total sugar,total acid,fructose,citric acid and malic acid had a rapid increasing course.The type of sugar accumulation of Nanguo pear is the intermediate type.