NIR transmittance estimation of free lipid content and its glycolipid and digalactosyldiglyceride contents using wheat flour lipid extracts.

ABSTRACT Free lipids (FL) in 72 hard winter wheat flours were extracted and dissolved in hexane. Absorbance (log 1/T) values were measured using a scanning spectrophotometer with a 2-mm cuvette, and used to develop calibration models for estimating flour FL content and glycolipid (GL) and digalactosyldiglyceride (DGDG) contents. Fifty-one calibration samples were selected based on the cutoff point of 0.3 of Mahalanobis distance, and the remaining twenty-one samples were used for validation. The best model for the estimation of FL content showed coefficients of determination (R2) of 0.95 for the calibration set and R2 = 0.89 for the validation set. Glycolipid contents could be estimated by a model which had R2 = 0.87 for the calibration set and R2 = 0.89 for the validation set. For DGDG, the best model showed R2 = 0.94 for the calibration set and R2 = 0.88 for the validation set.