Bioactive compounds’ contents, drying kinetics and mathematical modelling of tomato slices influenced by drying temperatures and time

Abstract

This study investigated the influence of drying temperature, and time on antioxidant activity, phenolic, flavonoid, lycopene and β – carotene contents of tomato slices. It also evaluated the influence of drying process on drying kinetics, moisture diffusivity and activation energy. Oven processed tomato slices had temperature-dependent significant increase in antioxidant activity at 30 and 60 min, phenolic from 30 to 120 min and lycopene contents from 120 to 300 min. Significantly decreased contents of flavonoid and β – carotene were obtained for oven processed tomato slices with increasing drying temperature and time. Page model accurately predicted the drying process of tomato slices. Similarity between experimentally determined moisture ratio and Page predicted moisture ratio was obtained with high correlation (R2 = 0.9986). Effective moisture diffusivities indicated that drying process of tomato slices was temperature dependent while Arrhenius equation explained the relationship between activation energy and temperature. Keywords: Page model, Drying temperature, Phytochemicals, Moisture diffusivity, Tomato slices