The fatty acid compositions of lipids from five local varieties and three imported varieties of soybean were determined. Total and free lipids of the samples were extracted with chloroform-methanol mixture (2:1, v/v) and ethyl ether, respectively. The ether-extracted samples were extracted again with water saturated n-butanol to obtain bound lipids. The average percent contents of the lipid fractions were 21070 (total), 18% (free), and 3.3% (bound). The results indicated that seven fatty acids (10:0, 12:0, 14:0, 16:0, 17:0, 20:0 and 22:0) were identified as minor fatty acids for all the varieties examined in this study. The relative contents of 18:2 were the highest (50.1-59.7%) in all the lipid fractions, and the contents in total and free lipids were in-fluenced by the local varieties. Little difference in fatty acid composition was noted between the total and free lipids of the samples. Total and free lipids contained more 18:1 (about 10%) and less 16:0 (about 40%) and 14:0 (about 34%) than did the bound lipids. The relative percent contents of 18:3 in the total, free and bound lipids were on average 8.9, 9.0, and 7.3 percents. The content in the total lipids of Gwanggyo varieties showed the highest level (11.1%), and in the bound lipids of Eundaedoo varieties the lowest (6.0%). In case of the total and free lipids, those varieties which showed higher relative contents of 18:1 generally had lower relative contents of 18:2 and 18:3.
|