Phitakwinai Sutida, Thepa Sirichai, Nilnont Wanich
Division of Energy Technology, School of Energy, Environment and Materials King Mongkut's University of Technology Thonburi Bangkok Thailand.
Department of Mechanical Engineering, Faculty of Engineering and Architecture Rajamangala University of Technology Suvarnabhumi Nonthaburi Thailand.
Food Sci Nutr. 2019 Jul 31;7(9):2921-2931. doi: 10.1002/fsn3.1144. eCollection 2019 Sep.
This paper presents thin-layer drying of parchment coffee (). Thin-layer drying of parchment coffee was conducted under controlled temperatures (50°C, 60°C, and 70°C) and relative humidities (10%-30%). The temperature of the drying air was important for drying at a high temperature, which results in the rapid removal of moisture and reduced time for drying. Nine thin-layer drying models (Newton, Page, Henderson and Pabis, logarithmic, two-term, modified Henderson and Pabis, two-term exponential, approximation diffusion, and modified-Midilli) were fitted to the experimental data for parchment coffee. The drying parameters of parchment coffee were related to temperature and relative humidity. The best model was the modified-Midilli model, which can be used to design the optimal dryer. The effective moisture diffusivity of parchment coffee drying was determined by minimizing the sum of squares of the deviations between the experimental data for the moisture content and the predicted values of thin-layer drying. The effective moisture diffusivity as a function of the temperature at each relative humidity was expressed by the Arrhenius-type equation.
本文介绍了羊皮纸咖啡豆的薄层干燥过程。羊皮纸咖啡豆的薄层干燥在可控温度（50°C、60°C和70°C）和相对湿度（10%-30%）条件下进行。干燥空气的温度对于高温干燥很重要，高温可使水分快速去除，缩短干燥时间。将九种薄层干燥模型（牛顿模型、佩奇模型、亨德森和帕比斯模型、对数模型、二项式模型、修正亨德森和帕比斯模型、二项式指数模型、近似扩散模型和修正米迪利模型）应用于羊皮纸咖啡豆的实验数据。羊皮纸咖啡豆的干燥参数与温度和相对湿度有关。最佳模型是修正米迪利模型，可用于设计最佳干燥机。通过使水分含量的实验数据与薄层干燥预测值之间偏差的平方和最小化，确定了羊皮纸咖啡豆干燥的有效水分扩散系数。在每个相对湿度下，有效水分扩散系数与温度的函数关系由阿伦尼乌斯型方程表示。
