热泵和热风干燥对龙眼干营养品质和褐变反应的影响

Effect of Heat Pump and Hot Air Drying on Quality Characteristics and Browning Reaction of Dried Longan

以龙眼果实(储粮)为研究对象,研究热泵和热风干燥对水分含量、5-羟甲基糠醛(5-HMF)、褐变度、维生素C、总多酚、糖组分、游离氨基酸和总氨基酸含量等与非酶褐变有关的基础物质和褐变度的变化情况。结果表明:在干燥过程中,蔗糖、维生素C、总多酚、游离氨基酸和总氨基酸含量显著降低;果糖及葡萄糖含量有少量增加;5-HMF及褐变度逐渐增加。表明了龙眼干制过程提供了龙眼果肉中发生非酶褐变反应的条件,并初步判断龙眼果肉中发生了美拉德反应,其中美拉德反应为龙眼干制过程中主要的非酶褐变反应。

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.