Analysis of contents and constituents of sugar and organic acid in different apple cultivars.

【Objective】 Primary sugars and organic acids of different apple cultivars were analyzed.The results could provide a theoretical basis for quality evaluation and quality improvement in apple.【Method】 HPLC(High Performance Liquid Chromatography) method was used to measure the soluble sugar and organic acid contents of 12 apple cultivars in this study.【Result】 The results indicated that the soluble sugars in apple fruit flesh included fructose,sucrose,glucose,and sorbitol,of which fructose content was much more than other sugars.Four apple cultivars(Qinguan,Starkrimson,FujiⅠand FujiⅡ) expressed the pattern of fructoseglucosesucrosesorbitol,however,the pattern of the other 8 apple cultivars(Hirosaki Fuji,Golden delicious,Huaguan,Pink Lady,Jonagold,Pinova,Jonathan,Granny Smith)was fructosesucroseglucosesorbitol;the organic acids in apple fruit flesh included malic acid,succinic acid,oxalix acid,citric acid,tartaric acid and acetic,of which the malic acid was the dominant one.The value of sweetness/acids in the cultivars(Qinguan,Huaguan) was higher(400),while in the cultivars(Golden delicious,Hirosaki Fuji,FujiⅠ,FujiⅡ,Jonagold) it was from 200 to 400,and in the cultivars(Starkrimson,Granny Smith,Jonathan,Pinova,Pink Lady) it was lower(200).【Conclusion】 The main soluble sugars in the cultivars(Hirosaki Fuji,FujiⅠ,FujiⅡ,Qinguan,Golden delicious,Jonagold,Starkrimson,Pinova,Huaguan)was fructose,the main soluble sugars in the cultivars(Pink Lady,Granny Smith,Jonathan) were fructose and sucrose;the main organic acid in 12 kinds of apple cultivars was malic acid.The value of sweetness/acids was an important indicator influencing the sweet and sour flavors of apple fruit.