WATER STATUS AND ANATOMIC CHANGES IN STORED ZUCCHINI (Cucurbita pepo L.)

Abstract

Zucchini fruits (Cucurbita pepo L.) show high metabolic activity and transpiration rates, and are highly susceptible to mechanical damage during harvest and postharvest. In this study, the effect of storage temperature on water status, cellular integrity and postharvest quality of zucchini were evaluated. Fruits in horticultural maturity stage s were stored 12 d at 10 and 20 °C, and 85 to 87 % relative humidity. Weight loss, relative water content (RWC), water potential (Ψ_w), osmotic potential (Ψ_π), pressure potential (Ψ_p), and cellular integrity observed through histological studies in fruits, were analyzed. The first sign of wilting ocurred with 6 % of weight loss. Cell tissue plasmolysis occurred between 81 and 82 % of RWC, when Ψ_p was equal to zero and Ψ_w and Ψ_π were equal to -0.8 MPa. Fruit tissue integrity was affected by the loss of adhesion cells at the endocarp zone which progressed to the pericarp.