Investigation of kinetics of amla (Emblica officinalis) fruit drying process

• Published in: South African journal of chemical engineering Vol. 41; pp. 10 - 16
• Main Authors: Raaf, Auliyaa, Putra, Tomy Wijaya, Mulana, Farid, Syamsuddin, Yanna, Supardan, Muhammad Dani
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2022; Sabinet Online; Elsevier
• Subjects: Amla; Diffusivity; Drying models; Microstructure; Moisture content; Indonesia; Microstructure; Moisture content; Amla; Diffusivity; Drying models
• ISSN: 1026-9185
• DOI: 10.1016/j.sajce.2022.03.011

This study aims to investigate the kinetics of the amla fruit drying process using oven and sun drying methods. The experimental results indicate that the final moisture content dropped with increasing drying temperature and decreasing material size. Oven drying has a faster drying time than sun drying. The heat loss during oven drying is lower than during sun drying, so the drying rate constant (k) for the oven drying method is higher than for sun drying. Moisture ratios for each drying condition are evaluated using three thin-layer models: Handerson–Pabis, Page, and Newton. The coefficient determination (R2) was used as a statistical parameter to determine the best drying kinetics model. Among the drying models examined, the Page model had the highest accuracy. An increase in drying temperature and a decrease in material size caused the effective moisture diffusivity value (Deff) to increase. The Deff values ranged from 4.522×10−10 to 1.361×10−9 m2/s. Analysis using scanning electron microscopy showed that the microstructure of amla fruit was significantly affected by varied drying conditions.
•Application of oven drying method at higher temperatures yields higher drying rates.•The final moisture content decreased with increased drying temperature and decreased material size.•Page model was able to predict the kinetic of drying processes with a high accuracy.•The effective moisture diffusivity increased with increased drying air temperature and decreased material size.•Temperature and drying method had significant influence on microstructure of amla.