Physico-chemical and physiological changes during fruit development and ripening of five loquat (Eriobotrya japonica Lindl.) cultivars

Physico-chemical and physiological changes during development and ripening of five loquat cultivars (Eriobotrya japonica Lindl., cv. Algerie, Cardona, Golden, Magdall and Peluche) were determined. Fruit growth showed a sigmoid curve in all loquat cultivars. A good relationship between duration of fast growth phase and fruit size was found. In addition, a positive correlation was also established between seed number and fruit size, and between seed weight and both fruit and flesh weight. Colour changes, sugar content increase and the decrease in fruit firmness and organic acids started simultaneously when loquat fruits were in the phase of fast growth, and at about 70-80% of their final weight. These physico-chemical changes related to fruit ripening coincided with an increase in both ethylene production rate and free and total 1-aminocyclopropane-1-carboxylic acid (ACC) content in the flesh. In addition, a small respiration peak associated with ripening was also detected. These results indicated that loquat fruits of all five studied cultivars showed a pattern of ripening in the tree that could be classified as climacteric, with relatively low ethylene production evolving at an early phase of fruit development.