不同冰温真空干燥压力对桂圆品质的影响  

Effects of different ice-temperature vacuum drying pressure on the quality of longan

作　　者：申江[1] 周成君 张川[1] 

机构地区：[1]天津市制冷技术重点实验室,天津商业大学,天津300134

出　　处：《食品科技》2017年第4期53-56,共4页Food Science and Technology

摘　　要：研究了在干燥温度为5℃,不同冰温真空干燥压力(0.2、0.4、0.6 k Pa)对桂圆失水率、复水特性、糖度和色差的影响以及桂圆干燥前、干燥后、复水后的感官对比。研究结果表明:舱内干燥压力越低,干燥速率越快,色差越大;舱内压力为0.2、0.4、0.6 k Pa桂圆干燥至10%的含水率的时间分别为31、32、34 h;0.2 k Pa压力下的色差值要比0.6 k Pa压力下的高22.6%;冰温真空干燥压力对桂圆的复水比、糖度的影响很小;干燥后的桂圆复水后能恢复到新鲜桂圆的87.4%,桂圆干燥后的平均糖度是干燥前的2.65倍。综合考虑干燥速率和色差的影响,干燥温度为5℃时,0.4 k Pa的干燥压力最适合干燥桂圆。The effect of different ice-temperature vacuum drying pressure（0.2, 0.4, 0.6 kPa） on the quality of longan in terms of quality attributes such as water loss rate, rehydration characteristics, Brix and color difference while the drying temperature stable in 5 ℃ and the sensory evaluation of fresh longan, dried longan and rehydration longan were studied. The results showed that the lower drying pressure, the faster drying rate and the greater color difference. The drying time of longan with the water rate reduced to 10% were 31, 32, 34 h accordingly, when the pressure in the tank were 0.2, 0.4, 0.6 kPa respectively. The value of color difference at 0.2 kPa was 22.6% higher than that at 0.6 kPa. The ice-temperature vacuum drying pressure almost had no effects on rehydration ratio and color difference. The drying longan after absorbing water could return to 87.4% of the fresh longan and the average Brix of dried longan is 2.65 times as high as that of fresh longan. Considering the effects of drying rate and color difference comprehensively, the best drying pressure is 0.4 kPa for longan when the drying temperature stable in 5 ℃.

关 键 词：冰温真空干燥 桂圆 干燥压力 品质 

分 类 号：TS255.42[轻工技术与工程—农产品加工及贮藏工程]