A reassessment of heat treatment as a means of reducing chilling injury in tomato fruit.
Whitaker, B. D.;
Postharvest Biology and Technology Year: 1994 Vol: 4 Issue: 1-2 Pages: 75-83 Ref: 21 ref.
1994
บทคัดย่อ
ABSTRACT :
Recent studies have indicated that heat treatment administered prior to chilling reduces the incidence and severity of chilling injury in tomato fruits and other plant organs. Partial ripening of tomato and other fruits has also been shown to reduce chilling sensitivity. To test the relative merits of these treatments, tomato fruits (cv. Rutgers) were harvested when mature-green, held for 3 days at ripening or heat-stress temperatures (20 or 38 deg C, respectively), chilled for 20 days at 5 deg , and assessed for ripening and injury over 7 subsequent days at 20 deg . Based on chromaticity (a*) values, lycopene content, rates of CO2 and ethylene evolution, and visible injury (pitting on shoulders), heat-treated (38 deg ) fruits sustained more chilling injury and ripened much more slowly than the partially ripened (20 deg ) controls. Membrane lipids extracted from outer pericarp tissue at 0 days and from 3-day partially ripened control and 3-day heat-treated fruits were also analysed. Lipid change
s after 3 days at 20 deg were typical of early ripening, whereas several anomalous changes occurred during 3 days at 38 deg , most notably a drop in steryl esters, large increases in phospholipids and cerebrosides, and a decrease in fatty-acid unsaturation in galacto- and phospholipids. These results indicate that, under certain conditions, heat treatment of tomato fruits may not reduce chilling injury as effectively as partial ripening.