Proton-induced X-ray emission analysis of the Chinese yam

Abstract

The Chinese yam is a major component of the Japanese diet consumed in raw and cooked form. It is important to determine the nutrient contents of yam, which contains high potassium levels; a simple measurement method is required. We performed proton-induced X-ray emission (PIXE) analysis of fully grown and immature yams. Analysis of the yam trunk, skin, and hair roots revealed that the skin potassium concentration was 10-fold higher than that of the trunk; consumption of the skin is thus recommended. Longitudinal measurements of mineral concentrations in a growing yam revealed that the concentrations increased in the growth direction.