Determination of 7S and 11S Globulins in Ground Whole Soybeans by Near Infrared Reflectance Spectroscopic Analysis

Abstract

A near infrared reflectance spectroscopic (NIRS) method was evaluated for potential usage in determining the amount of 7S and 11S globulins of ground whole soybeans. Near infrared reflectance spectra of the 7S and 11S fractions isolated from defatted soybean flakes were compared to search for characterized wavelenghts for each fraction. Subsequently, near infrared reflectance spectra of ground whole soybeans were measured and compared with those of the isolated 7S and 11S fractions. A multiple linear regression analysis with the data between ultracentrifugal and NIRS analyses on 7S, 11S and the ratio of 11S to 7S (11S/7S) was carried out to make a calibration using 18 calibration set. Correlation coefficients of the regression and standard errors of estimate of respective components from the regression were satisfactory. When performance of the calibration obtained was evaluated by using 8 unknown samples, the standard errorrs of difference between the values by ultracentrifugal analysis and NIRS prediction were 1.39%, 1.32% and 0.10 on 7S, 11S and 11S/7S, respectively. In conclusion, the results suggest that NIRS method has possibility of rapid determination for those components of ground whole soybeans.