Characteristics of organic acids in the fruit of different pear species

Abstract

The contents of organic acids in the fruit of 40 cultivars of four major pear species, Pyrus ussuriensis, Pyrus bretschneideri, Pyrus pyrifolia, and Pyrus communis, were examined using high performance liquid chromatography (HPLC). The results showed that the major components of organic acids present in the pear fruit were malic and citric acids. The total organic acid content and the individual contents of malic, citric, and quinic acids were significantly higher in the fruit of P. ussuriensis than in the other three species. Among the ten organic acids examined, both malic and citric acids exhibited highly significant positive correlation with quinic acid, whereas extremely significant negative correlation was observed between acetic and lactic acids, and between succinic and fumaric acids. Furthermore, significant positive correlation was observed between malic and citric acids, and between quinic acid and shikimic acids, whereas significant negative correlation was found between quinic and tartaric acids. The differences in the contents of the 10 individual organic acids and the total organic acid content in the fruit of the 40 pear cultivars reached a significant and strong level. Key words: Pear, fruit, quality, organic acid, difference, correlation.