Studies on Volatiles of Banana Fruits, Esterification of Added iso-amyl Alcohol in Pulp Disks

Abstract

Mechanism of esterification of alcohol using banana pulp disks was investigated. The alcohols, mainly iso-amyl, alcohl were added to the disks in the form of solution (infiltration method) or vapor. Conversion of isoamyl alcohol to acetate was not observed with mature-green banana while it occurred sharply in the course of ripening of fruits. The conversion was supposed to be enzymatic reaction, and some inhibitors (monoiodoacetate, sodium azide), N₂ atmosphere, soaking in water depressed the rate of esterification considerably. When banana pulp was homogenized, the reaction stopped and, on the contrary, iso-amyl acetate added was hydrolized rapidly. The addition of ATP and CoA did not show any effect on esterifiication, while the addition of acetic acid immediatly increased iso-amyl acetate production. Rapid esterification of added alcohol vapors (C₃ iso-C₄, C₄, iso-C₅, C₅) took place on pulp disks.