Rapid classification and quantification of marine oil omega-3 supplements using ATR-FTIR, FT-NIR and chemometrics

•Novel method was developed for classifying marine oils based on their lipid matrices.•Mid-infrared was more sensitive than near-infrared for the classification of oils.•Ethyl esters in triacylglycerols were correctly classified as mixtures at 11% (w/w).•Six quantitative models were developed for major fatty acids/fatty acid classes.•Procedures show promise for verifying accuracy of marine oil label declarations.