Characteristics of Components and Contents of Organic Acid in Pear Fruits from Different Cultivated Species
The components and contents of organic acid in 98 pear cultivars of five species at maturity were determined by the High Performance Liquid Chromatography (HPLC).The results indicated that total organic acid content in 98 pear cultivars varied greatly with a range of 1.28-23.47 mg · g-1 FW.Among five species,total organic acid content of P.communis was the highest,followed by P.ussuriensis,P.bretschnrideri and P.pyrifolia,the lowest species was P.sinkiangensis.The contents of malic acid and citric acid were the predominant organic acid in pear fruits,which varied with the range of 0.73-23.16 mg· g-1 FW and 0.02-15.29 mg.g-1 FW,and accounted for 55.91% and 37.08% of the total organic acid content,respectively.The content of citric acid was higher than malic acid in most cultivars of P communis,which were classified as citric dominant type.The cluster analysis of organic acid content revealed that P.bretschnrideri had close relationship with P.pyrifolia and P.ussuriensis,both P.communi and P.ussuriensis had higher organic acid,and P.communis showed distant relationship with other cultivated speices.