Role of pure oxygen treatment in browning of litchi fruit after harvest

Abstract

Experiments were conducted to test the effect of pure oxygen treatment on energy charge of peel tissue which may affect membrane integrity during browning of litchi fruit after harvest. Fruit were kept in air or pure O 2 for up to 6 days at 25 °C. Changes in browning index, membrane permeability, contents of ATP, ADP and AMP and energy charge were measured. As fruit browned, membrane permeability increased gradually, while ATP content and energy charge decreased rapidly. Exposure to pure O 2 significantly prevented peel browning, maintained high levels of ATP, ADP and energy charge, and reduced increase in membrane permeability of peel tissue of litchi fruit after 4 days of storage. The inhibition of browning of litchi fruit peel suggested that high levels of ATP, ADP and energy charge of litchi fruit kept in pure O 2 may contribute to maintenance of membrane integrity which reduced decompartmentation of enzymes and substrates resulting in enzymatic browning.