Drying kinetics of chilli under sun and microwave drying

Chilli (Capsicum annuum L.) is a popular spice used in Asia as a food flavour enhancer. Fresh chilli can not be stored for a long time because the water content reaches 70-80%. Drying can overcome the problem of storage and price fluctuations. The quality of dried chilli is determined by the water content, colour and content of active substances. A proper drying process is needed because an improper drying process can result in brown due to enzymatic or non-enzymatic reactions and loss of flavour. Prolonged drying using sun and hot air drying conduce brown colour, so a fast drying method is needed. This study aims to determine the drying kinetics of chilli dried by sun-drying and microwave drying. The experimental data were compared with several thin-layer models, while the diffusivity of the experimental results was compared with calculations based on the Ficks diffusion model. For sun drying, the best fitted model is Logarithmic with R-2 = 0,8267, RMSE = 0.1669, and SSE = 0,0592. While for microwave drying, the best-fitted model is Verma with R-2 = 0.9881, RMSE = 0.0473, and SSE = 0.0114. By using the mass transfer model it is known that the value for the evaporation constant is equal to 2,4531 x 10(-12) (sun drying); 5,24 x 10(-11) (microwave) and for the diffusivity value are 9.0695 x 10(-8) m(2)/s for sun drying while microwave drying is 6.1177 x 10(-7) m(2)/S. (C) 2022 Published by Elsevier Ltd.

Automated summary

Chilli is a popular spice that is commonly dried for storage. This study analyzed the drying kinetics of chilli using sun-drying and microwave drying methods. The results provided valuable insights into the drying process and mass transfer parameters.