Comparative drying of cornelian cherries: Kinetics modeling and physico-chemical properties

Abstract

Cornelian cherries (Cornus mas L.) were dried by convective, vacuum, and freeze drying. The main goal was to investigate changing of physico-chemical properties of cornelian cherries during different drying techniques. Moisture content, water activity, total color change, shear force, rehydration power, total phenolic, flavonoid and anthocyanin compounds, ascorbic and organic acids, and antioxidant activity were used as the most suitable quality indicators. The lowest moisture content, water activity, total color change and the lowest content of investigated organic acids, the highest rehydration power, and also the lowest loss of ascorbic acid were obtained in vacuum dried samples. In freeze-dried samples, the lowest shear force and the highest antioxidant activity were observed. The lowest loss of phenolic, flavonoid, and anthocyanin compounds were also obtained in freeze-dried samples. Eight empirical models were used for the description of vacuum drying process, and model Midilli et al. was selected as the most suitable. Practical applications Cornelian cherries present very popular sort of fruit with irresistible taste and specific texture. They also possess significantly high content of bioactive compounds. Drying parameters, mostly temperature, influence negatively on preservation of sensory and nutritive properties of cornelian cherries during drying. Thus, investigation of different impacts of each drying technique on physico-chemical parameters of cornelian cherries and also kinetics of cornelian cherries vacuum drying are useful both in scientific field and in industrial conditions. Based on this research, it could be seen, which drying parameters influenced the best on preservation of the most important physico-chemical properties of fresh cornelian cherries. Also, the most suitable empirical model used for the description of vacuum drying of cornelian cherries was observed.