[Main nutrients and functional ingredients in shoots of Polygonatum cyrtonema]

In order to reveal the main nutrients and functional ingredients in the shoots of Polygonatum cyrtonema, the polysaccharides, proteins, amino acids, and total phenols were determined. The tested samples cultured in Ma'nijiaonong, Hengtang village, Tianmushan town, Lin'an, Zhejiang, which were collected from three provenances(Pan'an and Longquan in Zhejiang and Qingyang in Anhui). The results showed that the polysaccharide content of the shoots varied from 2.34% to 12.73%, roughly one-third of rhizomes. The protein content varied from 107.75 to 192.49 mg·g~(-1), nearly 5.50 times more than rhizomes. Moreover, the average of total amino acid content was 193.13-248.74 mg·g~(-1), approximately 4.16 times of rhizomes. And the essential amino acids account for 35.57%-39.44% of the total amino acids content, which was close to the standard of the ideal protein proposed by FAO/WHO(the essential amino acid/total amino acid is about 40%). In addition, the taste amino acids(TaAA) changed from 160.12 to 208.29 mg·g~(-1), revealing the material basis of "shoots were extremely delicious" in Chinese ancient herbal medicine. Additionally, the total phenols varied from 51.21-58.76 mg·g~(-1), about 2.96 times of rhizomes. The DPPH free radical scavenging rate of tested shoots was over 95%, which obviously superior to rhizomes. Therefore, the shoots of P. cyrtonema is a very high-quality vegetable and functional food with good development potential. Furthermore, the main nutrients and functional substances in P. cyrtonema shoots are closely related to the provenances and harvesting seasons. It is important to improve the quality and yield of the shoots by strengthening the variety of breeding and cultivation techniques.