EFFECT OF DRYING KINETICS ON COLOR OF “DEDO DE MOÇA” CHILI PEPPERS (Capsicum baccatum)

ABSTRACT This study aimed to assess the drying kinetics of red and yellow chili peppers, “dedo-de-moça” variety, at different temperatures (35, 45, 55, and 70 °C) and model this phenomenon mathematically. We also evaluated the effect of these drying air temperatures on pepper fruit color. Pepper fruits were dried in a forced-air circulation dryer. Ten mathematical models were fitted to the experimental data by nonlinear regression analysis. After drying, pepper samples were analyzed for the following colorimetric parameters: lightness (L*), chroma or saturation (c), and hue angle (h), in order to determine the influence of drying air temperature on fruit coloration. Our findings showed that the higher the air temperature, the faster the drying process. Midilli model fitted well to all temperature data and best represented the drying kinetics of “dedo-de-moça” chili peppers. Moreover, fruit color was affected by the drying air temperatures, in which the higher the drying air temperature, the greater the color variation.

摘要 本研究旨在评估"dedo-de-moça"品种红、黄辣椒在不同温度（35、45、55及70℃）下的干燥动力学（drying kinetics），并对该干燥过程进行数学建模。同时，本研究还考察了干燥热风温度对辣椒果实色泽的影响。实验采用强制热风循环干燥机（forced-air circulation dryer）对辣椒果实进行干燥处理。通过非线性回归分析（nonlinear regression analysis），将10种数学模型拟合至实验数据集。干燥结束后，对辣椒样品的以下比色参数（colorimetric parameters）进行检测：亮度（L*）、彩度（chroma，又称饱和度，c）以及色相角（hue angle，h），以此明确干燥热风温度对果实着色的影响。研究结果显示，热风温度越高，干燥进程越快。Midilli模型可良好适配所有温度组的实验数据，最能准确表征"dedo-de-moça"品种辣椒的干燥动力学特性。此外，干燥热风温度会显著影响果实色泽，干燥温度越高，果实色泽变化幅度越大。