Primary study on ice temperature keeping during ice temperature vacuum drying

Ice temperature vacuum drying technology, which combined the advantages of ice temperature technique and vacuum drying technology, has great research values.But how to keep ice temperature during drying is a question which always limits the development of ice temperature drying technology.Based on this, by controlling the degree of vacuum, the temperature of cold storage and electric heating plate, this paper initially explored a method that could maintain the food at ice temperature during vacuum drying process.Taking black carp fillets as experimental materials, with freshness indicator K value, the drying rate and rehydration ratio as test indicators, a comparative study among ice temperature vacuum drying, freeze- drying and hot air drying was carried out.Research showed that freshness indicator K value of ice temperature vacuum dried black carp fillets was much better than that of hot air drying, and was close to that of freeze drying. Rehydration rate of ice temperature vacuum dried black carp fillets was slightly better than that of hot air drying. Drying rate of ice temperature vacuum drying was slower than that of hot air drying, but much faster than that of freeze drying.