Examination of rehydration ratio, color properties and drying kinetics of microwave dried garlic (Allium sativum L.)

Abstract

In this study, color values and rehydration ratios of dried garlic slices at four different microwave power (300W, 450W, 600W and 700W) were determined. Thin layer drying models were used for drying kinetics. It was determined that L* and b* values were lower and a* values were higher in microwave-dried garlic compared to fresh garlic slices. It was observed that the C* (Chroma) and h (hue angle) values of garlic decreased as the microwave power increased compared to fresh garlic. It was determined that the rehydration ratio decreased significantly with increasing microwave power. Therefore, the highest rehydration ratio was detected in the garlic samples applied at 300W. Moisture ratio (MR) versus time calculated as a result of microwave drying was compared with 5 (Lewis, Page, Henderson, and Pabis, Midilli et al. and Logarithmic) drying models in the literature. R2 (coefficient of expression), χ2 (chi-square) and RMSE (root mean square error) were calculated by SPSS and nonlinear regression analysis of dried garlic samples. It was determined that the highest R2 (0.994-0.998, the lowest RMSE (0.016-0.022) and χ2 (0.00033-0.00064) values belonged to the Lewis model.