苹果片双段控湿干燥特性及干燥品质工艺研究  

Drying characteristics, quality, and process optimization of apple slices during two-stage relative humidity-controlled drying

作　　者：效碧亮 效碧彩 刘晓风[2] XIAO Biliang;XIAO Bicai;LIU Xiaofeng(College of Materials and Chemical Engineering,Lanzhou College of Information Science and Technology,Lanzhou 730030,China;School of Life Science and Engineering,Lanzhou University of Technology,Lanzhou 730000,China)

机构地区：[1]兰州信息科技学院材料与化工工程学院,甘肃兰州730030 [2]兰州理工大学生命科学与工程学院,甘肃兰州730000

出　　处：《食品与发酵工业》2023年第5期237-246,共10页Food and Fermentation Industries

基　　金：甘肃省科技计划项目(18YF1NA002);甘肃省教育厅科技创新项目(2020A-185)。

摘　　要：为缩短苹果片干燥时间和控制产品品质,以多参数可控薄层干燥试验系统为手段,探索双段控湿工艺对干燥特性和品质的影响规律。以热风恒湿20%下干燥特性和品质为对照,系统研究了双段控湿干燥工艺参数热介质相对湿度、温度、流速和预处理蒸烫时间对干燥特性和品质特性的影响,品质特性以总色差ΔE*值、维生素C含量、5-羟甲基糠醛(5-hydroxymethylfurfural,5-HMF)含量作为衡量指标,并采用正交试验优化了工艺参数。结果表明,在试验范围内,双段控湿相对湿度对干燥特性和干燥品质均有显著影响(P<0.05),较优双段控湿条件为30%保持30 min调至20%,与恒湿干燥20%相比较,所需时间缩短了16.66%,产品ΔE*降低了39.71%、维生素C含量提高了15.20%、5-HMF含量与之无差异;双段控湿制干工艺参数介质温度、流速和预处理蒸烫时间对干燥特性和品质特性也有显著的影响(P<0.05)。双段控湿干燥工艺优化参数为:双段控湿30%(30 min)调至20%、蒸烫时间2 min、介质温度65℃、速率0.7 m/s,此条件下制得苹果片品相较好,ΔE*值为(9.397±0.62),5-HMF含量符合安全要求,为(7.403±0.66)mg/100 g,维生素C含量较高,为(121.951±3.07)mg/100 g;水分扩散系数1.267×10^(-6)m^(2)/s、干燥时间60 min;与对照恒湿20%相比,优化工艺干燥时间缩短了(66.67±1.28)%,制干产品ΔE*值和5-HMF含量分别降低了(47.74±0.58)%和(23.28±0.74)%,维生素C含量提高了(2.44±0.21)%。To shorten the drying time and control the quality of dried apple slices, the effects of relative humidity(RH), temperature, flow rate of hot air, and pretreatment steaming time of two-stage RH-controlled drying on the drying characteristics and quality of apple slices were studied. The drying process was optimized with an orthogonal design, using a multiparameter-controlled thin-layer drying system during the drying process. This study evaluated the quality characteristics of apple slices by the indicators of color ΔE*value, vitamin C content, and 5-hydroxymethylfurfural(5-HMF) content. The different RH of two-stage humidity-controlled had significant effects on the drying characteristics and quality of apple slices(P<0.05), and it was better when the RH of 30% was retained for 30 min in the first stage of drying, then was transformed to 20% to end. Compared with a constant RH of 20%, the drying time and the color ΔE*value reduced by 17% and 40%, and vitamin C content increased by 15%, with no significant difference in 5-HMF content. The impacts of air temperature and rate, and the pretreatment steaming time were also significant(P<0.05). The optimized process parameters of two-stage relative humidity-controlled drying at a relative humidity of 30%(30 min) to 20%, steaming time of 2 min, air temperature of 65℃, and air rate of 0.7 m/s were determined. The ΔE*value of the dried apple slices was(9.397±0.62), the content of 5-HMF was(7.403±0.66) mg/100 g, vitamin C was(121.951±3.07) mg/100 g, moisture diffusivity was 1.267×10^(-6)m^(2)/s, and the drying time was 60 min. This optimized condition was compared with the constant RH of 20%, the increase for vitamin C content was not very high, only(2.44±0.21)%, while the drying time was shortened by(66.67±1.2)%, the color ΔE*value and 5-HMF content of the dried product were reduced by(47.74±0.58)% and(23.28±0.74)%. Taken together, the optimized process was beneficial to improve the drying rate and control the product quality.

关 键 词：苹果片 控湿干燥 干燥特性 干燥品质 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]