摘要
以龙眼为研究对象,考察了不同热泵干燥温度和干燥风速对龙眼干一般理化特性、色泽、质构和活性成分等品质的影响。结果表明:采用高温热泵干燥时,干燥温度越高,龙眼干的总酸含量越高,复水率越低;干燥风速相同时,龙眼干的pH值随着温度的升高而降低;龙眼干燥后总体色泽的变化主要在色泽的变暗及变黄,干燥温度的升高和干燥风速的增加都会导致龙眼色泽变化的增加;总体来说,不同高温热泵干燥条件下,龙眼干的弹性、回复性、硬度以及耐咀性的变化均不显著,干燥风速较低,龙眼干的黏性较大;当干燥温度为60℃时,龙眼干中保留的游离酚含量最高,不同干燥条件下,结合酚含量、多糖含量的差异不显著。
The effects of different drying temperatures and different air velocities of high temperature heat pump drying （HTHPD） on general physicochemical properties, color, texture and active components of dried longan were investigated. Results showed that dried longan exhibited increased total acid content and decreased rehydration rate as the drying temperature increased. The pH value of dried longan decreased as the drying temperature increased at the same air velocity. Generally, the color of dried longan became darker （yellow） depending on both drying temperature and air velocity. The overall changes in springiness, resilience hardness, chewiness and cohesiveness of dried longan were not significant under different drying conditions. Adhesiveness value became higher when the air velocity was lower. The content of free phenolic compounds reached the highest level when the dyring temperature was 60℃, while the contents of bound phenolic compounds and polysaccharides were independent of the drying conditions.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2014年第4期30-34,共5页
Food Science
基金
广东省科技计划项目(2011B080202002
2011A08080311
2012B091000157
2012B040500058)
广东省农业科技项目(LNSG2012-14)
关键词
龙眼干
高温热泵干燥
干燥条件
品质
dried longan
high temperature heat pump drying
drying conditions
quality
