The effect of air assisted radiofrequency drying on chemical and physical properties of onion

In this study, drying of onions using air-assisted radiofrequency drying technique and changes in their quality values were investigated and it was aimed to evaluate the drying behavior of onion during drying in a hot air assisted radiofrequency system and also to evaluate the final powder quality obtained from onion. The effect of sample thickness, radiofrequency electrode gap on drying behavior was determined. The most efficient drying took place at 70 mm electrode gap and 2 cm sample thickness. This drying technique was also compared with other drying techniques, namely hot air, radiofrequency and freeze drying, in terms of quality values. Physical quality parameters such as moisture content, ash content and particle size and chemical quality parameters such as protein, total phenolic content and total antioxidant activity were used. In these comprehensive findings, it is clear that the hot air-assisted radiofrequency drying method holds great promise for the dehydration of onions, not only providing effective moisture removal but also preserving the quality, color and nutritional properties of the final product.