Optimization of microwave–infrared roasting of hazelnut

In this study, the possibility of using microwave–infrared combination oven for roasting of hazelnut was investigated. In addition, regression models for the responses: L* value, a* value, textural properties and moisture content of hazelnuts were obtained and the optimum roasting conditions were determined by using response surface methodology. Conventionally roasted hazelnut at 150 °C for 20 min was considered for comparison. For hazelnuts, 2.5 min roasting time at 90% microwave power, 60% upper halogen lamp power, and 20% lower halogen lamp power were found to be optimum roasting conditions. Hazelnuts roasted at this optimum point had comparable quality with conventionally roasted ones with respect to color, texture, moisture content and fatty acid composition.