5种干制方式对大果沙棘干燥特性及品质的影响

Effects of Five Different Drying Methods on Drying Characteristic and Quality of Hippophae rhamnoides

以新鲜的阿勒泰大果沙棘为材料,采用自然阴干(NSD)、自然晒干(ND)、热风干燥(HAD)、热泵干燥(HPD)和真空冷冻干燥(VFD)对其进行处理,分析5种干制方式对大果沙棘干燥特性及品质的影响。结果表明:5种干燥方式中,热风干燥和热泵干燥时间较短,分别为118和124 h,干燥率为100%,干燥时间较自然阴干和自然晒干缩短3倍以上,干燥速率提高5倍以上,真空冷冻干燥120 h后,大果沙棘干燥率仅为27.67%,继续增加干燥时间,其干燥效率基本保持不变,冻干效率低。与鲜样对比,真空冷冻干燥大果沙棘品质较好,可使果实色泽鲜艳,呈现出亮黄色,褐变度低,能够保持果实V_(C)和总酚含量。可见,在干燥效率方面,热风干燥和热泵干燥适于大果沙棘干制,但在干燥产品品质上,真空冷冻干燥效果较好。

Fresh Hippophae rhamnoides L.fruits from Altay were used as material,the treatments with shading drying(NSD),natural drying(ND),hot air drying(HAD),heat pump drying(HPD)and vacuum freeze-drying(VFD)were compared for their application to the drying of Hippophae rhamnoides L.,and effects of the five drying methods on the drying characteristics and quality of Hippophae rhamnoides L.were analyzed.The results showed that among the five drying methods,HAD and HPD had short drying times which were 118 and 124 h respectively,and the drying rate was 100%.The drying time was more than 3 times shorter than NSD and ND,and the drying rate increased 5 times more than them.After VFD for 120 h,the drying rate was only 27.67%.If the drying time continued to increase,the drying efficiency remained basically unchanged,and the freeze-drying efficiency was low.Compared with the fresh samples,Hippophae rhamnoides fruits dried by VFD could keep the better quality,and show the brightly yellow color,hold the lower browning,and maintain the higher V_(C) and total phenols content.In terms of drying efficiency,HAD and HPD were suitable for drying of Hippophae rhamnoides.However,in terms of the quality of dried products,VFD had a better effect.