Effects of indirect air cooling combined with direct evaporative cooling on the quality of stored tomato fruit

A 53 m3 solar-powered evaporative cooler for temporary storage of tomato fruit was developed to improve the shelf life of tomatoes under hot and humid climatic conditions. This study investigated the effect of indirect air-cooling combined with evaporative cooling (IAC+EC), maturity stage at harvesting and period of storage on the quality of tomatoes. The effect of total soluble solids, firmness, color, physiological weight loss (PWL), and marketability of tomatoes (star 9037) was investigated by monitoring the storage of green and pink maturity stage harvested fruit over 28 days under both IAC+EC and ambient conditions. The three factors had a significant effect (P < .001) on the overall quality of tomatoes. The tomatoes stored in the IAC+EC system were 18.9% firmer, maintained 10.5% lower concentration of sugars, increased the hue angle by 3%, had 6.31% lower PWL and were 24.8% more marketability than tomatoes stored under ambient conditions. The tomatoes harvested at the green stage were 20.2% firmer, had 6.6% lower total soluble content, increased the hue angle by 4.9%, had a 3.1% lower PWL, and were 11.6% more marketable than the pink harvested tomatoes. This study clearly demonstrated the efficacy of IAC+EC under sub-humid and hot conditions in improving the quality and marketability and increasing the shelf life of tomatoes by reducing the rate of ripening and utilization of sugar.