Kinetics of the changes in bio-active compounds, antioxidant capacity and color of Cornelian cherries dried at different temperatures

Abstract

The aim of this research was to determine the effects of oven-drying on degradation of bioactive compounds of Cornelian cherry including total monomeric anthocyanins, total phenolics, total flavonoids and L-ascorbic acid. Changes in antioxidant capacity, percent polymeric color and visual color were also used as quality indicators of Cornelian cherry dried at 50°, 60° and 70 °C for 36, 13.5 and 6 h, respectively. A zero-order kinetic model was obeyed for polymeric color formation. First-order reaction kinetics was found for the degradations of monomeric anthocyanins and L-ascorbic acid, while losses in total phenolics, total flavonoids and antioxidant capacity followed second-order kinetic model. The changes in color parameters also obeyed first-order kinetics. The activation energy for the degradations of bioactive compounds was observed in the range of 48.2–78.7 kJ moL−1. L* parameter with the highest activation energy (200.08 kJ moL−1) was pointed out in this study. Also, a higher sensitivity to temperature for the antioxidant capacity is evidenced by higher activation energy (83.3 kJ moL−1). This study concluded that drying at high temperature (70 °C) with a short time promoted retentions in bioactive compounds.