Co-Authors:
Ilic, Z., Faculty of Agriculture, 38219-Lesak, Serbia
Fallik, E., Volcani Center, Department of Postharvest Science of Fresh Produce, Bet Dagan, Israel
Abstract:
Chilling injury is a physiological disorder that develops in subtropical fruits such as tomatoes when they are exposed to non-freezing temperatures below 10°C. When a heat treatment was administered to tomato fruit their sensitivity to low temperature was reduced and they could be stored for up to a month at 2°C without developing chilling injury (CI). Heat stress with hot water dips (50°C for up to 1 min) and Hot Water Rinsing and Brushing (HWRB, a short-term treatment of pink tomato at 52°C for 15 sec) has potential for maintaining fruit quality and fruit resistance to chilling injury. Under stress, plants synthesize specific proteins, and their accumulation has a role in protecting the tissue from possible damage. The protective effects of heat treatment against CI in tomatoes has been correlated with the accumulation of heat shock proteins (HSPs) in fruit tissue (pericarp). The elevated temperatures initiates synthesis of these proteins HSP. Inhibition of normal protein synthesis and production of HSP were found at high temperature. Maximal production of HSP was found after 24 hours after treatment in both heat treatments. Synthesis HSP protein after 48 hours is smaller than after 24 hours or immediately after heat treatment. The protein continued to accumulate throughout the heating period and remained present during storage for 3 weeks at 2°C. Unheated control fruit did not developed full red colour after storage, and developed high levels of CI and decay.