Open-Air Sun Drying of Kokum (Garcinia indica) Rind and Its Quality Evaluation

Abstract

Open sun drying (OSD) is most common method of kokum drying in Western Ghats of India. Crop temperature, around the crop, solar temperature and rate of moisture evaporation are the important parameters of OSD of kokum. In this paper, an attempt has been made to study the OS drying characteristics of kokum rind, i.e., moisture content versus time, drying rate versus moisture content and moisture ratio versus drying time. The convective heat transfer coefficient operating in open sun drying conditions (natural convection) of kokum rind has also been determined based on the values of constants, C and n, which were obtained by linear regression analysis from experimental data for kokum rind. The quality parameters of kokum rind, i.e., acidity, pH, reducing sugar, non-reducing sugar, protein, carbohydrates, ash, anthocyanins, color (L, a and b value) and calorific value before OSD and after OSD of kokum rind have also be determined.