Kinetics and mathematical modeling of infrared thin-layer drying of garlic slices

Abstract

Drying of garlic slices in thin-layer have been studied with Infrared (IR) at 0.075, 0.15, 0.225 and 0.3 W cm radiation intensity and 0.75 and 1.25 m s air flow velocity. The results showed increasing in drying rate and decreasing at the time of drying with decreasing air flow velocity and increasing IR radiation intensity. The effective moisture diffusivity (D) was obtained using Fick's diffusion equation and its mean values ranged between 5.83×10 and 7.66×10 m s for all investigated conditions. In addition, a third-order polynomial equation linking the effective moisture diffusivity and moisture content was found. Average activation energy increased with the decrease of IR radiation and increase of air flow velocity. Thirteen different mathematical models were verified with non-linear regression analysis for describing the garlic drying process. Modified Henderson and Pabis model presented the best prediction of the drying of garlic slices.

Mathematical modeling and effect of drying temperature on physicochemical properties of new commercial grape “Kyoho” seeds

“…The results were in accord with the seminal study conducted by Roberts et al (), where it was suggested that the drying process of most food materials including grape seeds occurs predominately in falling rate period. Convergent results were observed in the drying process of food materials (Avhad & Marchetti, ; Younis et al, ). Based on the results, the findings have provided the insights on the effect of drying temperature on moisture loss, which is a prominent parameter in drying and quality considerations for industrial applications of Kyoho seeds.…”

“…However, the goodness of fit statistical results, such as χ2 , RMSE, %E, and SSE (Table ) was used to represent the quality of fit. The best suitable model was selected based on the combination of higher R 2 and lower χ2 , RMSE, %E, and SSE (Vega‐Gálvez et al, ; Younis et al, ). It was noticed that the R 2 values for the models ranged from 0.8587 to 1 at all temperatures.…”

“…This relationship between D eff and drying temperature may partly be explained by the kinetics that influences moisture content to move during the drying process. A number of studies have postulated a proportional relationship between D eff and temperature (Adiletta et al, ; Roberts et al, ; Younis et al, ). These findings are slightly higher than the study reported by Roberts et al (), where they concluded the D eff values ranged from 1.57 to 8.03 × 10 −10 m 2 /s for drying of three grape seed (Riesling, Cab Franc, and Concord) varieties.…”

“…Four thin layer models were used to fit experimental data as shown in Table . Lewis, Page, and Henderson–Pabis models were effectively used to model the drying process of grape seeds (Roberts et al, ), whereas the logarithmic model was used on many agricultural products (Souza da Silva et al, ; Younis, Abdelkarim, & Zein El‐Abdein, ).…”

“…Different mathematical model parameters were determined using nonlinear regression protocols—IBM® SPSS® software package (IBM® SPSS® Statistics version 22.0). The goodness of fit for each model was assessed based on the coefficient of determination ( R 2 ), chi‐square ( χ2 ), root‐mean‐square error (RMSE), the average percentage error (%E) according to the procedure of Younis et al (), and sum squared errors (SSE; Vega‐Gálvez et al, ). The selected models are considered as the best models based on the higher values of R 2 and lower values of χ2, RMSE, %E, and SSE.…”