Physicochemical characterisation of the postharvest senescence of the winter melon "Tendral"

Introduction. Tendral type muskmelon is a winter melon fruit having a dark green skin slightly netted and crisp and a white sweet flesh with a long storage life. Materials and methods. The senescence of the mesocarp of the winter melon Cucumis melo L. (Inodorus Group) Tendral, stored at 12 °C and ca. 75% relative humidity, was investigated during 100 d after harvest. Results. During storage, starch and sucrose become increasingly hydrolysed while the levels of reducing sugars increased. In this period the firmness and titratable acidity decreased, but an increase was found for protein and lipoperoxide concentrations. The colour parameters L, a and b were also affected, b showing the largest increase after harvest. Ethylene concentration remained minimal but the production of carbon dioxide varied significantly. The activities of catalase and glutathione reductase increased whereas ascorbate peroxidase and superoxide dismutase were inhibited. Discussion. The senescence of winter melon Tendral is coupled to starch and sucrose consumption and to the synthesis of organic acids required for the respiratory metabolism. Hydrogen peroxide and superoxide also seem to accumulate, triggering the lipoperoxidation of cellular membranes at a low rate.