RESPIRATION, PECTOLYTIC ACTIVITY AND TEXTURAL CHANGES IN RIPENING AFRICAN MANGO (IRVINGIA-GABONENSIS) FRUITS

Post-harvest changes in fruit firmness, respiration, pectinesterase (PE) and polygalacturonase (PG) activities were followed in African mango fruits during storage ripening at tropical ambient conditions (28 +/- 1-degrees-C and 68 +/- 2 % RH). Respiration followed a climacteric pattern attaining a peak of 99.37 ml CO2 kg-1 hr-1 on the fifth day of storage while full ripeness (colour index-5) was attained on the tenth day. PE and PG activities increased with progressive fruit ripening attaining their optima on the fifth day (1.8 PE unit) and tenth day (27 PG units), respectively. Fruit firmness decreased as pectolytic activity increased with a concomitant reduction in the deformation force from 49 kPa in the unripe fruit to 25 kPa at the edible ripe stage.