热风温度对苹果丁微波对流耦合加热干燥特性与品质的影响  

Effect of air temperature on microwave-convective coupled heating anddrying characteristics and quality of diced apple

作　　者：马玉荷 田晓菊 王应强[2] 赵红霞[2] 宋嘉玲 MA Yuhe;TIAN Xiaoju;WANG Yingqiang;ZHAO Hongxia;SONG Jialing(College of Food Science and Engineering,Ningxia University,Yinchuan 750021,China;College of Agriculture and Forestry Science and Technology,Longdong University,Qingyang 745000,China)

机构地区：[1]宁夏大学食品科学与工程学院,宁夏银川750021 [2]陇东学院农林科技学院,甘肃庆阳745000

出　　处：《食品与发酵工业》2024年第16期77-84,共8页Food and Fermentation Industries

基　　金：国家自然科学基金(32060544);庆阳市科技支撑项目(QNKB2-11);庆阳市自然科学基金项目(QY2921A-F018)。

摘　　要：该研究考察了热风温度(19.6、32.8、54.2、64.3、82.9℃)对苹果丁微波对流耦合加热干燥特性、微波输出图谱及品质的影响,并与单一的微波干燥和热风干燥进行对比。结果表明,在设定的物料最高点温度(80℃)条件下,热风温度对物料温度、干燥时间和产品质量影响显著。随着热风温度的上升,物料能达到的平均温度也上升,加热的均匀性也变好,干燥时间变短,苹果丁水分比均呈指数下降趋势。与微波干燥和热风干燥相比,耦合干燥可分别最大缩短50%和62.2%的干燥时间。当热风温度低于82.9℃时,微波呈现出不均匀的间歇式加热特征,当热风温度为82.9℃时则为分段式干燥过程。Weibull分布函数和Dincer模型可以准确描述苹果丁干燥过程,形状参数β表明干燥由内部水分扩散控制为主;毕渥数B_i说明干燥过程中温度变化由内部导热制约;估算水分扩散系数D_(cal)为2.40×10^(-7)~4.43×10^(-7) m^(2)/s,有效水分扩散系数D_(eff)为6.40×10^(-8)~4.55×10^(-6) m^(2)/s。在热风温度为64.3℃时,微波对流耦合干燥苹果丁的营养成分保留和感官评分最优。该研究结果为苹果丁微波对流耦合干燥应用提供理论参考依据。In this study,the effects of air temperature(19.6℃,32.8℃,54.2℃,64.3℃,and 82.9℃)on the microwave-convective coupled heating,drying characteristics,microwave output spectrum,and quality of the diced apples were investigated,and the comparisons among the single microwave drying,air drying,and microwave-convective coupled drying were done.Results showed that under the highest material temperature(80℃),the air temperature had a significant effect on the material temperature,drying time,and product quality.With the rise of air temperature,the mean temperature that the material could reach was higher,the heating uniformity was better,the drying time was shorter,and the moisture ratio of apple cubes showed an exponential downward trend.Compared with microwave drying and air drying,coupled drying could shorten the drying time by up to 50%and 62.2%,respectively.When the air temperature was lower than 82.9℃,the microwave worked in an uneven intermittent mode,and when the air temperature was 82.9℃,the drying proceeded in the segmented heating mode.Weibull distribution function and the Dincer model could accurately describe the drying process of diced apples.The shape parameterβindicated that drying was dominated by internal moisture diffusion control.The Biot number B i indicated that the material temperature change during drying was governed by internal heat conduction.The estimated moisture diffusivity D_(cal) ranged from 2.40×10^(-7) m^(2)/s to 4.43×10^(-7) m^(2)/s while the effective moisture diffusivity D eff ranged from 6.40×10^(-8) m^(2)/s to 4.55×10^(-6) m^(2)/s.The nutrient retention and sensory scores of the diced apple dried by the coupled microwave convection were the best when the air temperature was 64.3℃.The results of this study provide a theoretical reference for the application of coupled microwave-convective drying for diced apples.

关 键 词：微波 对流 耦合干燥 苹果丁 风温 品质 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]