Drying of different pepper varieties by microwave

The objective of this study was to investigate the effect of microwave on the drying and rehydration kinetics of green pepper varieties (sweet, green and bell) and the bioactive and textural properties of dried and rehydrated peppers. Microwave drying was carried out at 90, 180 and 90 + 180 W and dried peppers were rehydrated at 25, 50 and 70 °C in a water bath. The most appropriate model for drying were obtained using the equations defined by Sigmoid and Hii et al. Two term exponential decay model was determined as the most appropriate one for rehydration. The lowest and highest final rehydration ratio values were found for the peppers dried at 180 W and 90 W, respectively at each temperature and pepper variety. Bell pepper indicated the lowest color change (ΔE) among peppers. The peppers had softer texture in both drying and rehydration treatment. Total phenolic content of dried peppers was around 56-65% lower compared to the fresh pepper and this decrement was reached up to 87% in rehydrated peppers. No significant change was observed in antioxidant activity of dried peppers. As a result, drying at 180 W and rehydration at 70 °C provided faster drying and rehydration while maintaining the quality properties of green peppers.