Abstract

The potential of Fourier transform infrared (FT-IR), near-infrared (NIR), and Raman spectroscopic techniques combined with partial least squares (PLS) regression (PLSR) to predict concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total omega-3 fatty acids (n-3 FAs) in fish oil supplements was investigated. FT-IR spectroscopy predicted EPA (coefficient of determination (R²) of 0.994, standard error of cross-validation (SECV) of 2.90%, and standard error of prediction (SEP) of 2.49%) and DHA (R² = 0.983, SECV = 2.89%, and SEP = 2.55%) with six to seven PLS factors, whereas a simpler PLS model with two factors was obtained for total n-3 FAs (R² = 0.985, SECV = 2.73%, and SEP = 2.75%). Selected regions in the NIR spectra gave models with good performances and predicted EPA (R² = 0.979, SECV = 2.43%, and SEP = 3.11%) and DHA (R² = 0.972, SECV = 2.34%, and SEP = 2.60%) with four to six PLS factors. Both the whole and selected NIR regions gave simple models (two PLS factors) with similar results (R² = 0.997, SECV = 2.18%, and SEP = 1.60%) for total n-3 FAs. The whole and selected regions of Raman spectra provided models with comparable results and predicted EPA (R² = 0.977, SECV = 3.18%, and SEP = 2.73%) and DHA (R² = 0.966, SECV = 3.31%, and SEP = 2.56%) with seven to eight PLS factors, whereas a simpler model (three PLS factors) with R² = 0.993, SECV = 2.82%, and SEP = 3.27% was obtained for total n-3 FAs. The results demonstrated that FT-IR, NIR, and Raman spectroscopy combined with PLSR can be used as simple, fast, and nondestructive methods for quantitative analysis of EPA, DHA, and total n-3 FAs. FT-IR and NIR spectroscopy, in particular, have the potential to be applied in process industries during production of fish oil supplements.

Nondestructive quantification of the soluble-solids content and the available acidity of apples by Fourier-transform near-infrared spectroscopy

Yibin Ying, Yande Liu, and Yang Tao
Appl. Opt. 44(25) 5224-5229 (2005)

Quantitative analysis of bayberry juice acidity based on visible and near-infrared spectroscopy

Yongni Shao, Yong He, and Jingyuan Mao
Appl. Opt. 46(25) 6391-6396 (2007)

Identification and quantification of vegetable oil adulteration with waste frying oil by laser-induced fluorescence spectroscopy

Shiguo Hao, Lian Zhu, Ronglong Sui, Mengling Zuo, Ningning Luo, Jiulin Shi, Weiwei Zhang, Xingdao He, and Zhongping Chen
OSA Continuum 2(4) 1148-1154 (2019)

Laser-induced breakdown spectroscopy determination of toxic metals in fresh fish

L. V. Ponce, T. Flores, M. Sosa-Saldaña, F. C. Alvira, and G. M. Bilmes
Appl. Opt. 55(2) 254-258 (2016)

Far Ultraviolet Spectrophotometric Studies of Fatty Acids by Photoelectric and Spectrographic Methods*†

D. M. Kerns, R. Belkengren, Harold Clark, and Elmer S. Miller
J. Opt. Soc. Am. 31(3) 271-279 (1941)