Influence of delayed cooling on the quality of tomatoes (Solanum lycopersicum L.) stored in a controlled chamber

Abstract

Quality degradation due to inappropriate postharvest handling, including short exposure to high and variable temperature environments and cooling delay, is a critical issue for maintaining the freshness of vegetables and fruits in further marketing chains and final consumption. The goal of this research was to explore the influence of delayed cooling treatments on key quality attributes of tomatoes such as fresh weight, total soluble solids (TSS), firmness, and skin color (L*, a*, and a*/b*). Three treatments were applied to freshly harvested tomatoes: immediate storage (IS) after harvest, delayed cooling (DS) leaving tomatoes without cover for one day, and under cover (DSC) separately in a greenhouse and then storage in a controlled chamber at a temperature of 10 ± 1 °C and relative humidity of 90 ± 3%. The quality attributes of the stored tomatoes were examined for 15 storage days at 5-day intervals to examine the effects of cooling delay on the postharvest quality of tomatoes stored in a controlled chamber. After 15 days of storage, tomatoes that underwent the three treatments exhibited a progressive weight loss of 1.41%, 1.86%, and 1.69% for the IS, DS, and DSC treatments, respectively. Slower firmness reduction (31.2%) was observed for tomatoes with the IS treatment than for those with the other treatments over the storage duration. During the storage time, tomatoes that experienced the DS treatment exhibited higher increases in TSS (°Bx) values (4.79 to 5.76) than other tomato samples. Smaller changes in color values (L*, a*, and a*/b*) were observed for IS-treated tomatoes. During the storage time, overall changes were slower for IS-treated tomato samples than for those with other treatments. The results of this research indicate that the accumulation of field heat due to cooling delay could decrease the overall quality attributes of tomatoes in the market chain. The immediate transfer of harvested tomatoes to a cool temperature is strongly recommended.