Experimental study on the effect of different air supply temperature on forced-air precooling of lettuce

Abstract

During the forced-air precooling, the air supply temperature was the cold storage environment temperature. The air supply temperature was the most important factor to impact the fruits and vegetables precooling time and energy consumption in the condition of constant wind speed. In this experiment, the head lettuces precooled from 22 ℃ to 3 ℃. From 22 ℃ to half cooling time, it was selected 0 ℃, 2℃ and 4℃ as the air supply temperature in the precooling process of lettuces. Next the precooling was carried out from the half cooling time to 3°C at the blowing temperature of 0°C. The results were indicated that the air supply temperature changed from 2°C to 0°C was the best pre-cooling program to cooling down and save energy. In the actual production, it could develop the changed air temperature pre-cooling technology vigorously.