Effect of Blanching Pretreatment and Drying Model of Chrysanthemum indicum Linn.

บทคัดย่อ

The aim of this study was to investigate the effect of blanching pretreatment of Chrysanthemum indicum Linn. on drying performance and to develop mathematical drying models at a constant air velocity and temperatures (i.e., 1.0 m/s and 50, 60, 70 and 80°C). The required drying time to reduce moisture content from 6.01 ±0.44 g water/g dry matter of blanched, and 4.59 ±0.27 g water/g dry matter of fresh Chrysanthemum to 0.071 ±0.003 g water/g dry matter were 570, 445, 340 and 220 min, and 620, 480, 370 and 245 min, respectively. Empirical moisture content curves were fitted to the Newton, Page and Henderson and Pabis drying models. The Page model yielded the highest coefficient of determination (R2), the least chi-square and the lowest root mean square error (RMSE). The drying rates of the pre-treated Chrysanthemum were faster than those of untreated samples by 1.41, 1.42, 1.43 and 1.46 folds at 50, 60, 70 and 80°C, respectively. The activation energy for drying of pre-treated and untreated Chrysanthemum were well documented using an exponential expression based on by Arrhenius models and was found to be 30.38 and 33.41 kJ/mol.