Application and design of forced-air precooling equipment and techology for fruits and vegetables

Precooling of fruits and vegetables, an essential step for fresh products after harvest, is an important handling technology for the transportation and storage of postharvest fruits and vegetables. The technology is widely used in developed countries for precooling fruits and vegetables because of its low cost and easy operation. Such technology is also demanded for low input farm production of small scale and excessive crop varieties, and for expanding market with high quality requirement in China. Three kinds of precooling facilities with different cooling volumes were designed and manufactured, and a forced-air precooling cold room of 12 tons of cooling volume was constructed after the studies on the imported technology and forced-air precooling equipment. Generally the precooling time was about 4～6 h, only about 1/4～1/10 of cold room cooling time, and water loss was below 2%. The application in vegetable farmland showed that it could effectively keep the produce quality in storage and market, and also extend transportation distance.