Effects of Chelating Agent's Application on Soybean Mineral Composition and Seed Protein, Oil, and Fatty Acids.

In a greenhouse experiment, three-week-old soybean seedlings were exposed to various individual chelating agents of citric acid (CA), disodium EDTA (DSEDTA), salicylic acid (SA) and ferrous ion (Fe), and to the first three chelating agents combined with ferrous ion.  After the chemical applications, the plants were allowed to grow from May 15, 2010 until physiological maturity (first week of October). Seeds were analyzed for protein, oil, palmitic, stearic, oleic, linoleic, and linolenic acids, and macro- and micro-elements. The treatments Fe, CA, DSEDTA, and SA, had a major influence on seed composition by increasing the concentration of oleic acid (18:1) from 13 to 33.5%. These four treatments were found to decrease linolenic acid (18:3) content. The decrease of linolenic acid ranged from 17.8 to 31%. Treatments CA and SA increased protein content from 2.9 to 3.4 %.  Treatments DSEDTA+Fe and SA+Fe increased the oil content from 6.8 to 7.9%. For long shelf life of the oil, the increased content of relatively stable monounsaturated fatty acid such as oleic (18:1) acid rather than less stable polyunsaturated linolenic (18:3) or linoleic (18:2) acids in the soybean oil is desirable. The results of our study indicated that the CA, SA, DSEDTA and Fe treatments can alter seed composition, shifting the protein, oil, and fatty acids in seed. This may give opportunity for soybean farmers and industry for producing specific seed constituents, depending on the need of the industry or consumers.