Modeling
Gh. Amini; F. Salehi; M. Rasouli
Abstract
In this study, the effects of infrared (IR) dryer system parameters such as IR power, the distance of mucilage from lamp surface, mucilage thickness on drying kinetics and, color indexes (L*, a*, b* and ΔE) of wild sage seed mucilage (WSSM) were investigated in an IR dryer system. Experimental ...
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In this study, the effects of infrared (IR) dryer system parameters such as IR power, the distance of mucilage from lamp surface, mucilage thickness on drying kinetics and, color indexes (L*, a*, b* and ΔE) of wild sage seed mucilage (WSSM) were investigated in an IR dryer system. Experimental moisture ratio (MR) data were fitted to 7 various empirical thin-layer models. It was found that the Page model has the best fit to show the kinetic behavior and acceptably described the IR drying behavior of WSSM with the lowest mean square error (MSE), root mean square error (RMSE), mean absolute error (MAE), and standard error (SE) values and the highest correlation coefficient (r) value. The values of MSE, RMSE, and MAE for all experiments were in the range of 0.1×10-3-1.1×10-3, 1.04×10-2-3.25×10-2 and 8.7×10-3-27.1×10-3, respectively. The average effective moisture diffusivity (Deff) increased from 4.61×10-9 m2s-1 to 15.8×10-9 m2s-1 with increasing lamp power from 150 W to 375 W, while it was decreased from 14.4×10-9 m2s-1 to 5.16×10-9 m2s-1 and 13.2×10-9 m2s-1 to 4.31×10-9 m2s-1 with increasing the distance of mucilage from 4 to 12 cm and the reduction of mucilage thickness from 1.5 to 0.5 cm, respectively. Increasing in IR radiation power has a positive influence on the yellowness (increasing 19.78% in b* index) of dried WSSM. Also, it increased the color changes index (ΔE) from 16.05 to 17.59.
M. Rasouli; S. S. Seiiedlou Heris
Abstract
Garlic (Allium sativumL.) is one of the most important Allium spice. From an economic point of view, the dried garlic slices are valuable products. In this research, garlic slices as a thin layer were dried in a laboratory scale hot-air dryer, under air flow of 1.5 m/s, air temperatures of 50, 60 and ...
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Garlic (Allium sativumL.) is one of the most important Allium spice. From an economic point of view, the dried garlic slices are valuable products. In this research, garlic slices as a thin layer were dried in a laboratory scale hot-air dryer, under air flow of 1.5 m/s, air temperatures of 50, 60 and 70˚C and slice thicknesses of 2, 3 and 4 mm. The mean values of shrinkage of garlic slices obtained 69.8%. In addition, the effects of the drying variables on the shrinkage of dried garlic were evaluated. The ANOVA results indicated that the air temperature and slice thickness had no significant effect on final shrinkage of dried garlic slices. In order to derive and select the appropriate shrinkage model, four mathematical models were fitted to the experimental data. According to the statistical criteria (R2, SSE & RMSE) the best model was found to describe the shrinkage behavior of garlic slice.
