Biochemical changes in some tropical fruits during ripening.
El-Zoghbi M.
Author Affiliation: Food Science Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt.
Food Chemistry 49 : 33-37
Abstract : Changes during ripening in alcohol-insoluble solids (AIS) and dietary fibres in mango (cultivars Zebda and Baladi), guava (cv. Baladia), date (cv. Hayani) and strawberry (cv. Tioga) fruits are described. The activities of various degradative enzymes in the fruits were also studied. The results showed that the AIS and texture declined rapidly during ripening. The dietary fibres decreased as the fruits lost their firmness and became soft. Polygalacturonase and cellulase activities of the fruit tissues increased markedly during ripening in mango, guava and strawberry fruits. Both polygalacturonase and cellulase were absent or present at only a low level in green dates but increased in activity during ripening. The changes in polygalacturonase and cellulase activity were reflected in a reduction in fruit firmness and a decrease in anhydrogalacturonic acid and cellulose content during ripening. Pectinesterase activity decreased in mango, guava and strawberry fruits during ripening, but increased in dates during ripening even though the degree of pectin esterification decreased.