杜仲叶的营养评价及体外抗氧化活性分析

以杜仲叶为研究对象,采用常规理化方法对其干品的营养成分、主要功效成分进行系统分析,并利用营养评价手段及体外抗氧化实验评价其营养价值和抗氧化能力。结果表明,杜仲叶含有丰富的蛋白质(11.50 g/100 g),膳食纤维(38.40 g/100 g),α-亚麻酸(55.5%以脂肪计),以及钾(1.38×104 mg/kg)、钙(1.21×104 mg/kg)、镁(2.02×103 mg/kg)、铁(164 mg/kg)元素和多种微量元素。杜仲叶氨基酸含量丰富且种类齐全,已达优质蛋白标准。杜仲叶中的粗多糖、总多酚、总黄酮的含量分别为0.989、8.360、1.590 g/100 g,桃叶珊瑚苷、京尼平苷酸、绿原酸、松脂醇二葡萄糖苷、京尼平苷和芦丁这六种最具代表性的活性成分含量分别为0.765、3.020、2.670、0.013、0.024、0.067 g/100 g。体外抗氧化试验表明,杜仲叶提取物具有良好的抗氧化活性,在试验浓度范围,清除1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、2,2-联氮-二-3-乙基-苯并噻唑-6-磺酸自由基(ABTS+·)、羟基自由基(·OH)效果与质量浓度呈正相关,其半抑制浓度(IC₅₀)分别为32.89、28.09、235.3 mg/L。杜仲叶具有多种营养成分,且其提取物具有良好的抗氧化活性,作为新型食品资源具有广阔的应用前景。

Nutritional Evaluation and Antioxidant Activity Analysis in Vitro of Eucommia Ulmoides Leaves

In this paper,the nutritional components and main functional components of dried Eucommia ulmoides leaves were systematically analyzed by conventional physical and chemical methods,and the nutritional value and antioxidant capacity were evaluated by means of nutritional evaluation and antioxidant tests in vitro. The results showed that Eucommia ulmoides leaves had considerable protein(11.50 g/100 g)and large amount of dietary fiber(38.40 g/100 g),and contained abundant α-linolenic acid(55.5% in fat),potassium(1.38×104 mg/kg),calcium(1.21×104 mg/kg),magnesium(2.02×103 mg/kg),iron(164 mg/kg)and many microelements. Eucommia ulmoides leaves also contained a full range of amino acids,and met the high-quality standard of protein. The concentration of crude polysaccharide,total polyphenol and total flavonoids in Eucommia ulmoides leaves were 0.989,8.360 and 1.590 g/100 g,respectively,and that of aucubin,geniposidic acid,chlorogenic acid,pinoresinol diglucoside,geniposide and rutin were 0.765,3.020,2.670,0.013,0.024 and 0.067 g/100 g,respectively. The result of antioxidant tests in vitro showed that Eucommia ulmoides leaves had good antioxidant activity,and its scavenging ability for DPPH·,ABTS+· and ·OH was concentration dependent within a certain concentration range,while the inhibitory concentration 50%(IC₅₀)values were 32.89,28.09,and 235.3 mg/L,respectively. Eucommia ulmoides leaves have a variety of nutrients and its extract has good antioxidant activity,which has broad application prospects in food development as a new food resource.