The drying characteristics of chili pepper at three maturity stages under different drying conditions were studied under a hot air drying cabinet. The drying was performed at a relative humidity of 25%, 35%, and 45% and temperatures of 40 °C, 50 °C, and 60 °C. The response surface methodology was performed to find the optimal drying conditions. A mass transfer model was developed based on mechanistic Biot (Bi)- Dincer (Di) number correlations using those optimal drying conditions. The study showed that the color value of chili pepper was deteriorated with an increase in temperature. The suitable drying condition that produced the highest quality within the shortest drying time was a RH of 35% and a temperature of 50 °C for all maturity stages. The values of Bi numbers were affected by the maturity stage of the chili. Effective diffusivity and mass transfer coefficient of moisture increased with an increase in drying air temperature but decreased with an increase in drying air RH. The average value of moisture diffusivity and mass transfer coefficient decreased with chili maturity. The results indicate the capability of the mechanistic mass transfer model in predicting the drying characteristics, moisture diffusivity and mass transfer coefficient during the drying of chili pepper at different maturity stages.

在热风干燥箱中研究了辣椒在三个成熟阶段在不同干燥条件下的干燥特性。干燥在25％，35％和45％的相对湿度和40℃，50℃和60℃的温度下进行。进行响应表面方法学以找到最佳干燥条件。使用那些最佳的干燥条件，基于机械比奥（Bi）-丁克尔（Di）数的相关性，开发了一种传质模型。研究表明，辣椒的色值随温度升高而降低。在所有干燥阶段中，最短干燥时间内产生最高质量的合适干燥条件是RH为35％，温度为50°C。Bi值受辣椒成熟阶段的影响。有效水分的扩散率和传质系数随干燥空气温度的升高而增加，但随干燥空气RH的升高而降低。水分扩散系数和传质系数的平均值随着辣椒的成熟而降低。结果表明，机械传质模型能够预测辣椒在不同成熟阶段的干燥过程中的干燥特性，水分扩散系数和传质系数。