EXPERIMENTAL INVESTIGATION OF DRYING KINETICS OF CHERRY LAUREL

Abstract

ABSTRACT The present study was aimed at experimentally and theoretically investigating the drying kinetics of cherry laurel fruit (Laurocerasus officinalis Roemer) in a convective dryer. In the experimental part, effects of various values of drying air parameters, including temperature and relative humidity, on the drying characteristics of cherry laurel fruit were determined. Sorption isotherms of the dried cherry laurel fruit were also determined for different values of the temperature and the equilibrium relative humidity of the drying air. In the theoretical part, different thin‐layer drying models, such as Henderson and Papis, Newton and two‐term exponential models, have been used to analyze the moisture variation of cherry laurel. The two‐term exponential model was found to be the most suitable for describing the drying curves of cherry laurel fruit. A diffusion model was used to describe the moisture diffusivity at each temperature and relative humidity. The moisture diffusivity of cherry laurel varied between 1.896 and 3.252 × 10−10 m2/s. The temperature dependence of the diffusivity coefficient was also described by the Arrhenius‐type relationship. The activation energy of cherry laurel has been found as 15.806 kJ/mol.PRACTICAL APPLICATIONSDrying is used in order to preserve and store fruits for longer periods by removing some of their moisture content. In addition, commercial interest on dried fruits has been increasing. Improper drying causes considerable damage and waste of seasonal fruits in many countries. In the present study, some practical information about the drying kinetics of cherry laurel during convective drying is presented, which will be necessary for a food design engineer in the design and optimization of the drying system.