Effect of Pre-treatments on Drying, Rehydration, and Color Characteristics of Red Pepper ('Charliston' variety)

• Published in: Food science and biotechnology 2012, Vol.21 (4), p.1013-1022
• Main Authors: Doymaz, Ibrahim, Kocayigit, Fergun
• Format: Article
• Language: Korean
• ISSN: 1226-7708; 2092-6456

The drying characteristics of red pepper were examined in convection dryer at a temperature range of $55-70^{\circ}C$ with a constant air velocity of 2 m/s. The red peppers were pre-treated with ethyl oleate and citric acid solutions before drying process. Drying process continued until sample moisture fell down to 0.12 kg water/kg d.m. It was observed that drying, rehydration, and color haracteristics were significantly influenced by air temperature and pre-treatments. Moisture transfer from red peppers was described by applying the Fick's diffusion model, and the effective moisture diffusivity was calculated. The effective moisture diffusivity ranged from $5.72{\times}10^{-10}$ to $1.75{\times}10^{-9}m^2/s$ for the studied temperature range. The values of activation energy ($E_a$) were 50.27, 49.21, and 48.45 kJ/mol for control, pre-treated with citric acid, and ethyl oleate, respectively. Drying data was fitted to 4 drying models, and the best models were logarithmic and Page.