未成熟蚕豆中矿物质含量、氨基酸组成和微观结构的研究

研究了两个品种(凤豆15和18号)未成熟蚕豆三个食用阶段(S1、S2和S3)的种皮和胚中的矿物质(Ca、Mg、K、Fe、Zn、Mn、Cu和Cr)含量、整粒蚕豆蛋白的氨基酸组成以及胚的微观结构变化。结果表明,所有蚕豆样品中矿物质含量均表现为K > Mg > Ca > Zn,并均能检测到少量的Fe、Cu和Mn,均未检测到Cr,且大部分矿物质在种皮中的含量高于胚中;蚕豆蛋白中的主要氨基酸为谷氨酸(Glu)、天冬氨酸(Asp)、精氨酸(Arg)和亮氨酸(Leu),蛋氨酸(Met)和半胱氨酸(Cys)为其限制性氨基酸,必需氨基酸占总氨基酸含量的12.80%~37.35%,总氨基酸含量随着食用阶段的延后均呈显著上升趋势(P<0.05),且凤豆18号的总氨基酸含量显著高于凤豆15号(P<0.05);扫描电镜观察结果表明,随着食用阶段的延后蚕豆胚中的淀粉颗粒逐渐增大,且在凤豆15号中以多角形为主,而在凤豆18号中椭圆形或圆形占多数;相关性分析结果显示,两个品种的未成熟蚕豆中氨基酸的合成与矿物质的吸收富集没有明显的相互作用。

Mineral Content,Amino Acid Composition and Microstructure of Immature Vicia faba

The contents of minerals(Ca,Mg,K,Fe,Zn,Mn,Cu and Cr)in seed coat and embryo and the microstructure of the embryo were studied in three edible stages(S1,S2 and S3)of two immature Vicia faba(broad bean)varieties(Fengdou15 and 18). The results showed that the mineral contents of all broad bean samples were in order of K > Mg > Ca > Zn,and a small amount of Fe,Cu and Mn was detected,while Cr was not detected. The content of most minerals in the seed coat was higher than that in embryo. The main amino acids in broad bean protein were glutamate(Glu),aspartic acid(Asp),arginine(Arg)and leucine(Leu),while methionine(Met)and cysteine(Cys)were the limiting amino acids. Essential amino acids were accounted for 12.80%~37.35% of the total amino acid,and the total amino acid content increased gradually with the delay of edible stage(P<0.05). The total amino acid content of Fengdou 18 was significantly higher than that of Fengdou 15(P<0.05). Scanning electron microscope micrographs showed that the starch granules in the embryo of broad bean gradually increased with the delay of the edible stage,and the polygonal shape was dominant in Fengdou 15,while the oval or round shape was dominant in Fengdou 18.Correlation analysis showed that there was no significant interaction between the synthesis of amino acids and the absorption and enrichment of minerals in the immature broad beans of the two varieties.