Effect of Different Roasting Methods on Some Properties of Walnut Kernels

Abstract

In this study, the effects of oven roasting and microwave roasting on some properties of walnut kernels were determined. Roasting methods at different oven temperatures (70, 100, and 130 ºC for one hour) and at different microwave powers (240, 535 and 830 W for 5 min) were applied to samples. Moisture ratio values, total phenolic compound, antioxidant activity, and oil yield of the roasted and unroasted products were discussed. The highest oil yield was determined in the high temperature oven roasting but the microwave roasting mostly increased the oil yield of the product. Microwave roasting was found to be more suitable for decreasing moisture content. The lowest antioxidant activity was detected with microwave roasting. It was determined that the effect on the amount of phenolic substance in the two methods was indifferent.In this study, the effects of oven roasting and microwave roasting on some properties of walnut kernels were determined. Roasting methods at different oven temperatures (70, 100, and 130 ºC for one hour) and at different microwave powers (240, 535 and 830 W for 5 min) were applied to samples. Moisture ratio values, total phenolic compound, antioxidant activity, and oil yield of the roasted and unroasted products were discussed. The highest oil yield was determined in the high temperature oven roasting but the microwave roasting mostly increased the oil yield of the product. Microwave roasting was found to be more suitable for decreasing moisture content. The lowest antioxidant activity was detected with microwave roasting. It was determined that the effect on the amount of phenolic substance in the two methods was indifferent.