MASS TRANSFER KINETICS DURING CONVECTIVE DRYING OF RED PEPPER VAR. HUNGARIAN (<i>CAPSICUM ANNUUM</i> L.): MATHEMATICAL MODELING AND EVALUATION OF KINETIC PARAMETERS

Abstract

ABSTRACT Red peppers ( Capsicum annuum L.) var. Hungarian were dried at five inlet temperatures 50, 60, 70, 80 and 90C at a constant air velocity of 2.0 m/s. The equations of Newton, Henderson–Pabis, Page, Modified Page and Wang–Singh were tested for modeling drying kinetics. Besides, three newly empirical models were proposed on this study. The fit quality of the models was evaluated using linear determination coefficient, sum squared errors and chi‐square statisticals. The diffusivity increased from 0.702 to 3.783 × 10 −10 m 2 /s, showing the effect of temperature on this parameter, and with the Arrhenius‐type equation, an activation energy of 40.80 kJ/mol was obtained for the temperature range studied. In comparing the experimental moisture values with those calculated, it was shown that the Wang–Singh model gave the best fit quality, concluding that this equation is optimal for simulating drying kinetics as well as estimating drying time of this product. PRACTICAL APPLICATIONS The main utility of this study is the appliance of the empirical models using Newton, Henderson–Pabis, Page, Modified Page, Wang–Singh and diffusional equations in food dehydration, which can be considered a basis for a very accurate estimation of drying time. In this research, three newly mathematical models are proposed for the study of drying kinetics of food products, through which a good fit on the data of experimental moisture content was achieved. The study of drying kinetics of red pepper var. Hungarian engages a great technological interest, as this product is used in the development of paprika worldwide. In addition, dried red pepper var. Hungarian and others dried pepper exports from Chile have become especially important, including raisins, prunes and apples. The major markets for these products include the USA, the European community and Japan.