恒温及变温气体射流冲击干燥对猕猴桃片干燥特性及品质的影响

为了提高猕猴桃片的干燥品质,缩短干燥时间及降低能耗,本试验以猕猴桃为原料,采用气体射流冲击干燥技术对猕猴桃片进行干燥,研究恒温和变温对猕猴桃片干燥特性及品质指标的影响。结果表明,猕猴桃片恒温及变温气体射流冲击干燥均属于降速干燥;风温对猕猴桃片的气体射流冲击干燥特性有影响;变温干燥条件下含糖量与恒温40℃时无显著差异,可滴定酸含量与恒温70℃时无显著差异;70→40℃变温干燥的猕猴桃片回复性和维生素(Vc)保存率最高,色差(ΔE)值介于50℃恒温干燥和70℃恒温干燥组之间;70→40℃变温干燥方式的单位能耗显著低于40→70℃变温干燥组。70→40℃变温干燥方式加工的猕猴桃片综合品质最佳,本研究为变温气体射流冲击干燥技术应用于猕猴桃片的干燥提供了技术支持。

Effects of Constant and Alternating Temperatures Air Impingement Drying on the Drying Characteristics and Quality of Kiwifruit Slices

In order to improve the drying quality of kiwifruit slices, shorten the drying time and reduce the energy consumption, the kiwifruit slice was dried by air impingement drying. The effects of constant and alternating temperatures on the drying characteristics and quality of kiwifruit slices were studied. The results showed that both the drying process of constant and alternating temperature air-impingement drying of kiwifruit slice occurred in the falling rate period. Air temperature affected the drying characteristics of kiwifruit slices. There was no significant difference in sugar content between the alternating temperature drying and constant temperature at 40℃. The difference in titratable acid content between the alternating temperature drying and the constant temperature of 70℃ was not obvious. The resilience and the Vitamin C preservation rate of the alternating temperature drying (70→40℃) were higher, and its ΔE value was between constant temperature drying at 50 and 70℃. The unit energy consumption of the 70→40℃ drying method was significantly lower than that of the 40→70℃ drying method. In summary, the kiwifruit slices processed by the 70→40℃ cooling drying method had the best integrated quality. The research provided a technical basis for the application of alternating temperature air-impingement drying technology in kiwifruit slices.