Development of Evaporative Cooling System for Preservation of Tomato

Abstract

The portable tomato cooler was developed and evaluated for storage capacity of 50 and 200 kg having overall dimensions of 900 x 800 x 770 and 1320 x 900 x 1100 mm respectively. To evaluate its performance, different filling materials such as tef straw, wheat straw, sacks (doniya) and sponge (foam) was used. Selection of filling material was based on the cost, water holding capacity, rate of evaporation of water from filled material and easy availability. Tomato fruits were stored in an on-farm evaporative cooler for 19 days. The effect of filling materials on Physiological weight loss (PLW), inside temperature, inside relative humidity and cooling efficiency of four filling materials were studied. The weight loss varied between 8.51 to 23 % and 5.09 to 14.89 % during storage in 200 and 50 kg capacity evaporative cooler respectively.  The mechanical test such as cooling efficiency for each filling material was determined and it was recorded as maximum in sponge and rages from 91 to 95 %. The maximum storage life of 19 days was found in sponge. Sponge (foam) was performed better when compared with other filling material. It was most economical filing material over the other filling materials.