Effect of Heat Pump and Hot Air Drying on Quality Characteristics and Browning Reaction of Dried Longan
Longan fruit(CHU Liang) was used as the materials for studying the effects of heat pump and hot air drying on the moisture content, 5-HMF, vitamin C, total polyphenols, sugar components, free amino acids and total amino acid content, as well as with non-enzymatic browning relationship. The results showed that during the drying process, sucrose, vitamin C, total polyphenols, free amino acids and total amino acids significantly decreased; small amount of fructose and glucose content increased; 5-HMF and browning increased. It was further confirmed that the drying process provided the conditions for the occurrence of non-enzymatic browning reaction,and preliminarily judged a Maillard reaction was occurred during the drying process, which was the major non-enzymatic browning reaction for longan drying.