The effect of germination upon the fat of the soybean

Abstract

Abstract Soybeans of the Chippewa variety of two crops, 1956 and 1957, were germinated in the dark at 25C and the levels of total dry matter and crude fat of both the seedling axis and cotyledons were determined at various periods up to 12 days. The fatty acid content, neutral fat content of the crude fats of the cotyledons, and the fatty acid composition of neutral fat were determined. The fatty acid composition was measured by the ultraviolet spectrophotometric method. There was a continuous decrease in the total dry matter and crude fat of the cotyledons and whole seedlings of soybeans during 12 days of germination, contrary to observations of some of the earlier workers. Although there was a preferential utilization of the non‐fat dry matter during the first two days of germination, there was a slight but significant loss of fat, which gradually increased with the germination time. Surprisingly little change in the fatty acid composition of the reserve triglycerides occurred even during their most rapid loss from the cotyledons. However, observed changes were statistically significant. No loss of oleic acid occurred until after the second day of germination and its more rapid loss; compared to the other fatty acids, occurred during the period of most rapid fat loss. The significance of this observation and its relationship to oleic acid as the key intermediary in fat metabolism in plants is discussed.