Optimized parameters and quality analysis of salty and crisp peanut by far-infrared roasting

In order to improve the quality of salty and crisp peanut, the optimized parameters of salty and crisp peanut by far-infrared roasting using orthogonal design, and the quality changes of salty and crisp peanut during roasting were investigated. The results showed as follows: the optimized parameter for far-infrared roasting was 0.312 kg/kW peanut roasted at 130℃ for 2.5 h. During peanut roasting, the acid value (AV) and peroxide value (POV) in salty and crisp peanut increased slowly, which would not significant affect its quality under the optimized parameter by far-infrared roasting. Whereas, contents of reducing sugars and free amino acids decreased for maillard reaction during roasting, which was beneficial to roasting flavor of salty and crisp peanut, and activities of lipoxygenase (LOX) and the anti-nutritional factors such as trypsin inhibitor in peanut (PTI) also declined. LOX activity was completely inactivated when salty and crisp peanut roasted at 130℃ for 0.5 h, and PTI activity was almost completely inactivated when salty and crisp peanut roasted at 130℃ for 2.5 h. The inactivation of activities of LOX and PTI could improve storing stability and edible quality of salty and crisp peanut.