Raman and Infrared Spectroscopic Data Fusion Strategies for Rapid, Multicomponent Quantitation of Krill Oil Compositions

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, r 2 p = 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, r2 p = 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%, r 2 p = 0.99) than models from either Raman (RMSEP = 4.5%, r 2 p = 0.90) or IR (RMSEP = 7.3%, r 2 p = 0.73). Data fusion also significantly improved quantitation accuracy for quantification of other fatty acid classes.

Development and Validation of a Simple Method to Quantify Contents of Phospholipids in Krill Oil by Fourier-Transform Infrared Spectroscopy

“…The representative FT-IR spectra of krill oil and fish oil samples are shown in Figure 1 within the range of 4000–400 cm −1 [ 3 , 5 ]. Table 1 summarizes the assignment of significant FT-IR signals based on the previously reported literature [ 1 , 36 , 37 ].…”

“…Omega-3 polyunsaturated fatty acids play an important role in human physiology; therefore, they are widely used as health supplements [ 1 , 2 , 3 ]. Recently, krill oil extracted from Antarctic krill ( Euphausia Superba ) has attracted attention as a source of long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) [ 4 ].…”

“…Additionally, second-derivative FT-IR spectroscopy was used to discriminate the authenticity of perilla oil [ 27 ]. Very recently, a study was conducted to analyze the composition of EPA, DHA, and astaxanthin in krill oil by combining FT-IR and Raman spectroscopy [ 1 ].…”

Lake snow caused by the invasive diatom Lindavia intermedia can be discriminated from different sites and from other algae using vibrational spectroscopy

“…Raman spectra were collected using FT Raman system described previously. [ 15 ] Briefly, spectra of dried L. intermedia samples from different locations and sample depths were collected using a Bruker MultiRam spectrometer (Bruker Optics, Ettlingen, Germany) equipped with a liquid N 2 cooled Ge detector (D418T) and an Nd: YAG continuous wave laser emitting at 1064 nm. Spectra were acquired using OPUS software v.6.5 with 200 mW power setting for 200 co‐added scans at 4 cm −1 resolution with a downward‐looking objective (DWLO).…”

Rapid Quantitation of Adulterants in Premium Marine Oils by Raman and IR Spectroscopy: A Data Fusion Approach

“…Raman spectroscopy also offers the opportunity to analyze components of interest through packaging. One example is the analysis of FOs through gelatin capsules [ 2 , 14 ], where the successful quantification of pigments, such as carotenoids, were detected at low concentrations [ 14 , 15 ].…”