The outcomes of this work are firstly to study the influence of operatory parameters (drying temperature, the thickness of yam slices, the treatment with ascorbic acids (AA) and benzoic (AB) on the effective diffusivity during Dioscorea cayenensis yam, and secondly to model the drying kinetics according to the semi-empirical approach, by using the models of Henderson and Pabbis, the model of Page, the model of Wang and Singh, and the model of Two terms. As a result, temperature and thickness of thin layers are two main parameters having significant effects on the diffusion coefficient during drying. The increasing of drying temperature from 50 to 90oC for drying slices of thickness E= 4.76 mm increases the diffusion coefficient from 1.685× 10-11to 4.57×10-11 m2s-1. For a slice thickness (E= 4.65 ±0,15 mm), or an increasing of effective diffusivity of factor 2, 712.The influence of cutting thickness has been also noticed on the variation the effective diffusivity. Then the diffusion coefficient increases from 9.45 × 10-12 to 4.57 × 10-11 m2.s-1 for the thickness increase from 1.87 to 4.76 mm or an increase of factor 4.836. Yet we remark a feeble difference between treated slices and non-treated slices. The drying kinetics modeling reveals us the values R2, of reduced ki-square and RMSE vary respectively from 0.94059 ≤ R2 ≤ 0,99985, 0.000023 ≤ χ2 ≤ 0.01019 et 0.000138 ≤ RMSE ≤ 0.684400. Among the four (4) models tested in all experimental conditions, the PLAGE mode describes better the drying kinetics of yam slices with R2= 0.99985, χ2= 0.000023 and RMSE = 0.000138 (a yam sample of 1.87 mm thickness treated with ascorbic acid at 2% and dried at 90 oC).
