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.