Drying of Red Pepper (Capsicum Annuum): Water Desorption and Quality

Capsicum annuum samples were dried at different air-drying temperatures, ranging from 30 to 90ºC. Modelling of the drying curves was satisfactory when the Page model (average percentage of explained variance was 99.0 ± 0.2%) was used, whereas the Peleg model provided a less accurate simulation (average percentage of explained variance was 91± 14%). Both k and n parameters of the Page’s model exhibited a clear temperature dependence. In fact, n parameter varied linearly with the temperature (r2=0.92), whereas k parameter followed an Arrhenius relationship (r2= 0.96). An activation energy value of ca 27 kJ/mol was estimated using the Page equation. Air-drying temperature influenced the final quality of the dried red pepper (paprika). According to the results, drying within the range of 50 to 75ºC, would be the optimum conditions to achieve a final product with the best colour characteristics (highest ASTA and chroma values) and also, with the highest antioxidant capacity.