Convection Drying Influence on Thermo-Physical Properties, Bioactive Substances, Color and Texture Profile of Red Pepper (Capsicum Spp)

Abstract

Abstract This work aimed to study the effect of convection drying on bioactive substances and on the texture profile of red pepper. Four mathematical models were used to model the drying kinetics, as a function of the temperature and the thickness of slices. These models are largely in agreement with experimental data. Effective diffusivity, Arrhenius constant, activation energy and thermal properties changed with temperature of dry process. The two varieties of pepper used in this work demonstrated a very high degree of spiciness (144799.37-160899.37 SU). This property is related to the high contents of capsaicin (39.60-44.01 mg/g) and dihydrocapsaicin (32.33-35.95 mg/g). Our results revealed that brittleness, hardness 1 and 2, firmness, chewiness, gumminess appearance and Young’s modulus are very important attributes in determining the textural profile of dried red pepper. Also, drying causes a strong degradation of natural pigments of red pepper and consequently decreases attractiveness of the texture profile. To avoid that, red pepper should be pretreated before the application of hot air drying.