多花黄精嫩芽主要营养与功效成分研究

Main nutrients and functional ingredients in shoots of Polygonatum cyrtonema

为了揭示多花黄精嫩芽中主要营养与功效成分,采集浙江省杭州市临安区天目山镇横塘村麻泥角弄人工栽培的多花黄精(包括浙江磐安、浙江龙泉、安徽青阳3个种源)展叶前、展叶初期和展叶盛期3个不同时期的嫩芽,测定多糖、蛋白质、氨基酸、总酚等含量。结果表明:多花黄精嫩芽中多糖质量分数为2.34%~12.73%,约占根茎的1/3;蛋白质质量分数达107.75~192.49 mg·g-1,为根茎的5.50倍;总氨基酸质量分数为193.13~248.74 mg·g-1,为根茎的4.16倍,其中人体必需氨基酸占总氨基酸的35.57%~39.44%,接近FAO/WHO提出的理想蛋白质的标准(必需氨基酸占总氨基酸40%左右),味觉氨基酸(TaAA)达到160.12~208.29 mg·g-1,揭示了历代本草"初生苗,味极美"的物质基础;总酚质量分数51.21~58.76 mg·g-1,是根茎的2.96倍;对DPPH自由基清除率均达95%以上,明显优于根茎。因此,多花黄精嫩芽是一种非常优质的野菜与功能食品,具有很好的开发潜力。此外,多花黄精嫩芽中主要营养与功效物质与种源、采收季节等密切相关,加强品种选育、嫩芽培育技术研究,对提高嫩芽质量与产量十分重要。

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.