CHANGES IN THE ACTIVITIES OF CARBOHYDRATE-DEGRADING ENZYMES WITH RIPENING IN MUSA-PARADISIACA

The activities of phosphorylase (EC 2.4.1.1), amylase (EC 3.2.1.2) and invertase (EC 3.2.1.26) were monitored in the pulp and peel of post-harvest plantain (Musa paradisiaca L) stored at 26-degrees-C and at 14-degrees respectively. There was a significant increase (P < 0.01) in the activities of the three enzymes in both the pulp and peel of plantain fingers stored at 26-degrees-C as ripening progressed as assessed by the unpaired t-test. The increase in amylase activity was more dramatic, thus suggesting a greater hydrolytic rather than phosphorolytic cleavage of starch. The enzyme activities in the plantain stored at 14-degrees-C also increased with the post-harvest storage period (P < 0.01) although the absolute values were less than those from the corresponding plantain fingers stored at 26-degrees-C. The possible importance of these observations in the light of reducing the large wastage of M paradisiaca due to poor storage facilities, and thereby enhancing its shelf life and usefulness in the tropics, is discussed.