Mathematical Modelling of Drying Characteristics of Lemon Grass Leaves (Cymbopogon citratus)

Abstract

Drying characteristics of Lemon grass leaves using an oven dryer was studied at four different temperatures (40, 50, 60 and 70°C). The effect of the drying temperatures on moisture content of the leaves was investigated. Thirteen drying models were fitted to the drying data to establish the model that best describes the drying characteristics of Lemon grass leaves. The best model was determined by the model with the lowest value of SSE and root mean square error (RMSE), and the highest value of coefficient of determination (R2). Hii et al. model satisfied the conditions for selecting the most suitable and reliable model with R2, SSE and RMSE values of the model was 0.9964, 0.0250 and 0.0214 respectively. This model is most suitable at 40°C. The effective diffusivity (Deff) values ranged from 8.92452 × 10-12 m2/s to 16.00657 × 10-12 m2/s and increases as temperature increases. It was further observed that the amount of energy required to eliminate moisture within the leaves was in the range of 19.85 kJ/mol - 19.86949 kJ/mol. Dried lemongrass leaves can be used in food preservation as an alternative to synthetic substances that have recently become less acceptable to consumers. Consumers accept natural food products that are universally acknowledged as safe, such as lemon grass with essential oils, and they also fit the standards for green processing.