CULTIVAR SUSCEPTIBILITY AND ANATOMICAL EVALUATION OF TABLE OLIVE FRUIT BRUISING

Fruit bruising caused by physical impact is a major problem for mechanical harvesting of table olives, particularly in the case of green processing. We have initiated studies of the bruising process which include timing of the appearance of the surface discoloring, comparison of the degree of bruising among three different table olive cultivars and 14 new genotypes from a breeding program, and histological observations. Timing was monitored by photographs at successive times following standardized bruising by dropping from one meter high onto a floor field. To compare the degree of bruising among genotypes and cultivars a visual scale was established for evaluating fruits, which were processed in lye and saltwater according to standard commercial procedures. We observed significant differences among genotypes in sensitivity to the bruising. Histological sections of bruised and unaffected fruit tissues revealed a subsurface zone of tissue discoloration but a much greater area in which cell structure was altered but not damaged. Those observations support the hypothesis that the bruising phenomenon consists of both chemical and physical processes which differ in the area which is affected and the progression of the effect.