Identification of the Geographical Origin of Asian Red Pepper (Capsicum annuum L.) Powders Using H-1 NMR Spectroscopy

Abstract

Red pepper (Capsicum annuum L.) is a highly popular vegetable in Asia used for food seasoning in powder form. In this study, H-1 NMR spectroscopy combined with canonical discriminant analysis was applied to differentiate the geographical origin of Korean, Chinese, and Vietnamese red pepper powders distributed in Korea. Through the quantitative analysis of metabolite peaks in the H-1 NMR spectra of 62 red pepper powder extracts, seven discriminant variables with significant differences between origins were identified. The canonical discriminant functions derived from the discriminant variables could correctly classify the geographical origins of all the Asian red pepper powder samples. The capability of the discriminant functions was further examined by discrimination of the origins of 16 additional blind red pepper powder samples. This study shows that H-1 NMR spectroscopy is a useful method to discriminate red pepper powder origin with the appropriate canonical discriminant analysis of signals associated with metabolites.