Studies on degradation characteristic of cell-wall polysaccharide during peach fruit ripening

Cell wall materials(CWM) were prepared from honey peach(Yuhua 3) fruit at different maturity and extracted sequentially into four pectic polysaccharide fractions(CDTA-1,CDTA-2,Na_2CO_3-1 and Na_2CO_3-2),three hemicellulosic fractions(KOH-1,KOH-2 and KOH-3) and cellulose rich fraction(CWM-residue).Gas chromatography was used to determine the sugar composition of these fractions,to demonstrate the modifications of the content and sugar composition of several polysaccharides in the course of peach softening accompanied with the changes of fruit firmness.The results showed that,during peach fruit softening,the backbone of pectins rich in galacturonic acid took rupture,arabinose and galactose that lied in the side chains of pectin,hemicellulose and cellulose were also degraded.The degradation of galacturonic acid and galactose associated closely with the set-up of honey peach fruit ripening,whereas the degradation of arabinose probably contributed to later ripening and softening.