摘要
新鲜的榴莲蜜舍糖量高，水分多，是一种很容易腐烂的水果。为了能够延长贮存时间必须降低含水量。由于舍糖量高，当用传统的热风干燥进行干燥时，榴莲蜜表面会出现焦糖化。为了克服这个问题，在干燥的开始阶段应用间歇热泵干燥机，在干燥中期应用低温的除湿空气。结果表明：利用循环温度和递升温度干燥的样品湿含量可降低到0．081—0．110（g水／g干物质k此研究中用有限差分法来估算有效扩散系数值，较好地模拟了干燥动力学数据。就产品质量而雷，在循环温度干燥中减少热风干燥时间可生产柔软的干燥产品。而且，低温除湿空气的缓苏作用能减少干燥样品的总体颜色变化。
Fresh chempedak is a highly perishable fruit, rich in sugar content and has high moisture content. As such its moisture content is to be reduced for preservation for an extended period of time. Due to its high sugar content, cameralization tends to occur on the surface when conventional hot air drying is used. In order to overcome this problem, low temperature dehumidified air was applied in the middle and at the beginning of drying process using an intermittent heat pump dryer. The results revealed that the moisture content of samples dried using cyclic temperature profile and step-up temperature profile drying can be reduced to the range of 0.081 to 0.110 g H20/g DM. Finite-difference method （FDM） was applied in this study to estimate the effective diffusivity values and the drying kinetics data was well simulated. In terms of product quality, reducing of hot air drying duration during cyclic temperature drying produce softer dried products. Further to this, it was found that low temperature dehumidified air tempering can reduce total color change of dried samples.
基金
马来西亚科学技术部的支持
"e-Science基金"的资助(03-02-12-SF0001)
关键词
榴莲蜜
低温除湿空气
有限差分法
有效扩散系数
产品质量
总颜色变化
hempedak
low temperature dehumidified air
finite-difference method
effectivediffusivity
product quality
total color change
