Comprehensive evaluation on nutritional characteristics and anti-hyperglycemic active ingredients of different varieties of Yam

Yam is a versatile economic crop that serves both medicinal and dietary purposes. Dehua County, located in Fujian Province, China, is renowned as one of the major yam production areas, with a cultivation history spanning over 600 years. It has successfully cultivated Qingfeng yam and Ziyu yam, both of which have been recognized with China's "Geographical Indications for Agricultural Products." However, no comprehensive studies have been conducted to evaluate their quality. This study meticulously utilized the authentic medicinal material "Iron yam" as a benchmark, employing advanced techniques such as high-performance liquid chromatography (HPLC), ultraviolet spectrophotometry, and flame atomic absorption spectrometry to systematically analyze the nutritional and hypoglycemic active components of three distinct yam varieties. In order to interpret the data, descriptive statistics, correlation analysis, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), cluster analysis and multiple linear regression analysis were systematically applied. The results revealed significant variations in the concentrations of various indicators across the three yam types. Correlation analysis identified 65 pairs of indicators with exceptionally strong correlations and 39 pairs with statistically significant associations. Additionally, the principal component analysis demonstrated that Iron yam exhibited the most favorable overall quality. Notably, Ziyu yam, characterized by its high concentration of hypoglycemic active compounds, emerged as a promising raw material for the production of hypoglycemic products, showcasing significant potential in this field.