The Functional Components of By-Product Resources from the Aerial Parts of Polygonatum cyrtonema Hua

Abstract

The rhizome of Polygonatum, which has been consumed in China for nearly 2000 years, is rich in oligosaccharides, polysaccharides, saponins, and alkaloids and has various effects such as lowering blood sugar and anti-aging. Its aerial parts are often discarded as by-products and have been rarely studied; moreover, the nutritional composition and carbohydrate composition of these parts are not clear. In this study, the nutritional composition, amino acid evaluation, and the total phenolics content of the leaves, stems, fruits, and flowers of Polygonatum cyrtonema Hua were analyzed, and the composition and content of carbohydrates were determined by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC–PAD). The results suggested that the leaves and flowers of Polygonatum cyrtonema Hua (PC) contained 1.12–1.37% phenolic substances. The proteins of the aerial parts had high nutritional values, and the total amino acid content of the leaves and flowers, with the total leaf amino acids amounting to 11.77%, were followed by the flowers at 11.65%. The sugars in the flowers were mainly free monosaccharides at 10.38%, and the fruits were dominated by 9.44% fructo-oligosaccharides. This study provided new evidence for the utilization of the aerial parts of Polygonatum.