Drying Characteristics and Quality of Red Pepper Slices Under Hot Air Followed By Microwave Finish Drying

Abstract

Red pepper slices were subjected to hot air, microwave and hot air followed by microwave finish drying. The hot air-drying experiments were conducted at temperatures of 45, 55 and 65°C. Micro-wave experiments were carried out at 780 W micro-wave power level. Hot air followed by microwave fin-ish drying decreased the drying time required when compared to drying with hot air drying. Among the five thin layer drying models that were used to fit the experimental data, Page and Modified Page models gave the highest correlation coefficient, lowest root mean square error, and reduced chi-square, thus in-dicating that Page and Modified Page models best de-scribed the hot air drying of red pepper slices. In this study, ascorbic acid degradation and color changes during drying were also investigated. In the drying process at 65ºC for 9 hours, ascorbic acid content de-creased to 330.94±1.45 mg/100g dry matter after 8 hours. After 8 hours, no ascorbic acid was found. Moreover, the kinetics of ascorbic acid and color changes of red pepper slices, due to drying by hot air drying were studied. It was confirmed that ascorbic acid degradation followed first order kinetics. The re-sults indicate that hot air followed by microwave fin-ish drying may be an alternative method for the dry-ing of red pepper slices since it provides good quality product in shorter time. © 2023, Latin American Applied Research. All Rights Reserved.