Change of Polyphenol Compounds in Banana Pulp during Ripening

Abstract

In mature green bananas before ripening, 103mg/100g of polyphenol compounds were contained in the pulp and about 60% of those polyphenol compounds have a MW above 2×10⁵ and an astringency. These high molecular weight polyphenol compounds produced cyanidin, delphinidin and catechin on hydrolysis with HCl and were proanthocyanidins consisting of leucoanthocyanidin and catechin. The changes in polyphenol compounds during ripening have been studied with separating by ultrafiltration and ion-exclusion chromatography and the result showed that the polyphenol compounds with a MW above 2×10⁵ and an astringency disappeared during ripening. However, no change was seen in those polyphenol compounds with a MW below 2×10⁵. These results suggest that the disappearance of astringency by ripening treatment is resulted from the polymerizing insolubilization of polyphenol compounds with a MW above 2×10⁵, the astringent components.