Polyuronides Changes in Japanese and Chinese Pear Fruits during Ripening on the Tree

Abstract

Changes in contents and molecular distribution of polyuronides were determined on Japanese pear 'Chojuro' (Pyrus serotina Rehd. var. culta) and Chinese pear 'Yali'(P. ussuriensis Maxim. var. sinensis Kikuchi) fruits. The ratios of water-soluble (F1) fraction to total polyuronides increased and that of acid-soluble (F4) fraction decreased as firmness decreased with ripening in both cultivars. However, 'Chojuro' contained polyuronides of predominantly lower molecular weight than did 'Yali' in the F4 fraction.