The average protein concentrations for the 2012 U.S. soybean crop was slightly lower compared to the 2011 U.S. crop and average oil content was slightly higher, according to a survey supported by the American Soybean Association and the U.S. Soybean Export Council.
The average U.S. soybean protein concentration was 0.5 percent lower in 2012, at 34.3 percent, and average oil was virtually unchanged (0.3 percent higher at 18.5 percent), when compared with 2011 numbers (34.8 percent and 18.2 percent, respectively). The Western Corn Belt states showed lower protein concentrations (34 percent) than the U.S. crop as a whole. Midsouth and Southeast states commonly produce a soybean crop with higher protein concentrations (35.4 percent and 35.2 percent, respectively) than other regions, according to the survey results.
In 2012, the study was expanded to include amino acid analyses. When expressed as a percent of the protein, the 10 essential amino acids (lysine, methionine, threonine, tryptophan, cysteine, leucine, isoleucine, histidine, phenylalanine and valine) did not appear to vary between regions.
Sample kits were mailed to producers selected so that response distribution would closely match state soybean production. In all, 1,903 samples were received. These were analyzed at the University of Minnesota for protein and oil concentration by near-infrared spectroscopy using a Perten DA7250 diode array instrument (Huddinge, Sweden) equipped with calibration equations developed by The University of Minnesota in cooperation with Perten.
