Effect of maturity on the phenolic compositions of pear juice and cell wall effects on procyanidins transfer

Perry pear polyphenols were characterized in fruit, juice and pomace for two cultivars and at two maturity stage. Cell walls were characterized only in fruits and pomaces. The phenolic contents and compositions of fruits did not change during overripening. However, their extraction to juice was modified. Juices of ripe fruits contained 38% (Plant de Blanc) and 28% (De Cloche) of initial polyphenols, whereas overripe pear juices contained only 26% and 15% respectively. Thus, procyanidins had more affinity for cell walls after overripening. Pear cell walls from De Cloche cultivar lost arabinose and galactose from pectic side chains during overripening promoting non-covalent interactions between procyanidins and cell walls