Abstract
The effect of fluctuating temperature on chilling injury in the fruits of eggplant, snap bean, cucumber and sweet pepper was investigated, comparing with those held at steady temperature. In the fluctuating temperature treatment (square-wave form), samples were kept on the fluctuating conditions which were combined with the amplitudes of fluctuation at ±5°C, ±3°C, ±2°C or ±1°C and the periods of onecycle for 24-hour, 12-hour or 6-hour respectively, when standard temperature was 6°C which seemed to occur chilling injury.
The decrease in the occurrence of pitting injury of eggplant fruit was directly proportional to the amplitude of the fluctuation and the length of the fluctuating period. The increase in chlorogenic acid content was also delayed as the fluctuating amplitude widened. At a standard temperature of 6°C, the conditions of fluctuating temperature at which chilling injury of eggplant fruit was clearly ameliorated were an amplitude of ±5°C and a period of 12-hour or 24-hour. The fluctuating temperature promoted the amelioration of pitting injury of snap bean fruit as effectively as that of eggplant fruit. It could not, however, be observed that the temperature fluctuation had a positive effect on the amelioration of chilling injury of cucumber fruit and sweet pepper fruit. Although in cucumber fruit pitting injury occurred more often at the fluctuating temperature than at a steady temperature of 6°C, this was probably due to the greater chilling-sensitivity of cucumber fruit compared to eggplant fruit.
