Study the effectiveness in preprocessing of cinnamon chips

Abstract

Drying process has been identified as one of the most important preprocessing techniques in cinnamon oil production industry. Drying at closed and controlled environment was selected as a solution to mitigate the drawbacks of conventional sun drying of cinnamon. The common drawbacks are long processing times, labor cost and the deterioration of the quality due to several factors such as dust, moisture and insects. Optimizing the drying operation can reduce the post harvesting losses. This research focuses on investigation of the drying behavior of cinnamon chips and the effect of drying on the yield and quality of cinnamon bark oil. Drying process was experimentally investigated using a tray dryer which provided convective drying with hot air. This dryer consisted of a stove, heat exchanging system and drying chamber and is driven by biomass. Hot air temperatures of 35C, 40C, 45C and 50C were selected while the air velocity was kept constant. The applicability of three commonly used mathematical models was evaluated by examining the best fit for drying at each tray of the dryer separately. The particle size of cinnamon chips available in the market was having a large range from less than 1/8 inches to greater than 6 inches. However about 29.7% of cinnamon chips were in the range of 1 inch to 2 inches. The moisture content of cinnamon chips available in the market was found to be within a range of 14.12% to 28.56% with mean and standard deviation of 19.97% and 4.58% respectively. The common practice in the industry is to keep the cinnamon chips under wet conditions before drying until a considerable amount is collected. This process seriously affects the oil yield as mould and fungi develops under wet conditions. The maximum number of days in storage under wet conditions without affecting the quality of cinnamon chips was found to be 3 days. The drying behavior of cinnamon chips in a tray dryer had well agreed with the existing drying models for thin layer drying. Considering the total drying time and the oil yield, drying temperature of 35C was found to be the most suitable temperature for drying of cinnamon chips. Drying at temperatures above 35C gave lower yield and the high volatile components had escaped during drying operation. Drying was not even within the tray dryer and results of the variation of moisture content at each tray clearly indicated the non-uniform drying behavior. Non-uniform drying had considerably reduced the yield which was significant when the drying temperature was maintained above 35C.