Effect of Temperature and Genotype on the Crude Glycinin Fraction (11S) of Soybean and Its Analysis by Near-Infrared Reflectance Spectroscopy (Near-IRS)

The crude glycinin fraction (11S) of soybean [Glycine max (L.) Merr.] protein has desirable quality characteristics. The objectives of this soybean study were the following: (1) to develop a near-infrared reflectance spectroscopy (near-IRS) equation for screening of the 11S fraction; (2) to determine relationships between the 11S fraction, crude protein, and oil concentration; and (3) to study the effect of growing temperature and genotype on this fraction. Three near-IRS 11S equations were developed, with the best equation having a moderate standard error of calibration (7.7 g/kg) and coefficient of determination (R² = 0.84). A positive correlation was observed between the 11S protein subunit and crude protein concentration (r = 0.69, P < 0.01), and a negative correlation was found between the 11S protein subunit and oil concentration (r = -0.67, P < 0.01), based on 319 genotypes. Higher crude protein and 11S protein subunit concentrations were associated with higher growing temperatures, and higher oil concentration was associated with lower growing temperatures, based on 12 genotypes.