Raman and Infrared Spectroscopic Data Fusion Strategies for Rapid, Multicomponent Quantitation of Krill Oil Compositions
Fatema Ahmmed, Ioan D. Fuller, Daniel P. Killeen, Sara J. Fraser‐Miller, Keith C. Gordon
Abstract
Krill oil contains eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), long chain omega-3 polyunsaturated fatty acids with essential roles in human health, and astaxanthin, a naturally occurring keto-carotenoid that protects EPA+DHA against oxidation. Here, we assess Raman and IR spectroscopy (as stand-alone techniques and paired using three different data-fusion approaches) as methods for simultaneous quantitation of EPA+DHA and astaxanthin in krill oil. Raman spectroscopy could accurately (RMSEP = 40 μg g–1, r2p = 0.98) quantitate astaxanthin in krill oil despite its low concentrations (212–693 μg g–1). This analysis could be performed directly through gelatin capsules with no loss of prediction accuracy (RMSEP = 27 μg g–1, r2p = 0.99). Fusing IR and Raman data did not improve the astaxanthin quantitation models. EPA+DHA quantitation was more accurate using “mid-level” fusion (RMSEP = 1.2%, r2p = 0.99) than models from either Raman (RMSEP = 4.5%, r2p = 0.90) or IR (RMSEP = 7.3%, r2p = 0.73). Data fusion also significantly improved quantitation accuracy for quantification of other fatty acid classes.