Cellulase Activity and Fruit Softening in Avocado

Abstract

Cellulase activity in deteched avocado (Persea americana Mill.) fruits apparently was directly correlated with ripening processes such as climacteric rise of respiration, ethylene evolution and softening. This activity in the pericarp could be induced by ethylene treatment and the more mature the fruit the faster and the greater was the response. Only a very low cellulase activity could be detected in hard avocado fruit right after harvest. Cellulase activity was highest at the distal end of the fruit, lower in the midsection and lowest at the proximal end. The enzyme is heat-labile and appeared to have activity of an endocellulase nature mainly. Electron micrographs of cell walls from hard and soft fruits are presented.