Effect of grafting, cultivar and cold storage on eggplant fruits

Abstract

Eggplant is a perishable fruit that, once harvested, can be stored at 10 °C for several days. If long stored, fruits reduce their texture, skin brightness and become rubbery. Recently, grafting onto Solanum torvum has become more and more used to give resistance to biotic and abiotic stresses. The aim of this work was to study the effect of grafting, cultivar and cold storage on post-harvest changes of eggplant fruits. Grafted or ungrafted plants of four cultivars were grown in an unheated greenhouse during autumn-spring period. Three cultivars had skin with very dark purple colour (Black Bell, Black Moon and Longo) and one had skin with unhomogeneous light purple colour (Birgah). After harvesting, three berries per treatment were packed in perforated PE bags and stored at 10°C for 14 days. To evaluate post-harvest changes during cold storage, weight loss, skin colour (lower and upper section), pulp browning and oxidation potential were measured for each sample. In order to evaluate the oxidation potential, a cross section 1.0 cm wide was excised from the central section of fruits. Pulp colour was rapidly measured immediately after cutting and after 30 and 60 min. The oxidation potential was expressed as ΔL30 = L0-L30 and as ΔL60= L0 -L60. Grafting did not affect quality and colour of eggplant fruits during cold storage. Black Bell and Black Moon showed the highest values of pulp oxidation.