Variation of Crude Protein and Amino Acids Concentrations in Corn, Wheat, and Barley from Different Countries

The objective of this study was to investigate the variability in crude protein (CP) and amino acids (AA) content in cereal grains imported from different origins in Korea from 2006 to 2015. The values of CP and AA contents in corn, wheat, and barley were obtained from 430 and 325 samples from six countries, 83 and 56 samples from seven countries, and 60 and 58 samples from three countries, respectively. The CP concentrations in corn, wheat, and barley ranged from 7.12 (Brazil) to 7.68% (India), 10.55 (Ukraine) to 13.26% (Brazil), and 9.46 (India) to 10.49% (Ukraine), respectively. The Lys concentrations in the corn, wheat, and barley ranged from 0.18 (Argentina) to 0.24% (China), 0.26 (India) to 0.34% (China), and 0.23 (India) to 0.31% (Australia), respectively. The concentrations of CP and AA varied among different countries of origin ( P <0.05), except for Met in wheat and CP in barley. The coefficients of variation for CP were 3.26, 9.06, and 5.36 from corn, wheat, and barley, respectively. The correlation coefficients (r) between CP and Lys concentrations in corn, wheat, and barley were positively correlated and were 0.322, 0.277, and 0.542, respectively. In conclusion, CP and AA concentrations varied not only from different countries of origins but also within the same country due to the geographic region in which they are produced.