Fatty Acid Determination in Human Milk Using Attenuated Total Reflection Infrared Spectroscopy and Solvent-Free Lipid Separation.

Autores de IIS La Fe

• Victoria Ramos García

  Autor

• Isabel Ten Doménech

  Autor

• Julia Kuligowski

  Autor

Participantes ajenos a IIS La Fe

• Akhgar CK
• Nürnberger V
• Nadvornik M
• Schwaighofer A
• Rosenberg E
• Lendl B

Grupos

• Perinatología

Abstract

This study introduces the first mid-infrared (IR)-based method for determining the fatty acid composition of human milk. A representative milk lipid fraction was obtained by applying a rapid and solvent-free two-step centrifugation method. Attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy was applied to record absorbance spectra of pure milk fat. The obtained spectra were compared to whole human milk transmission spectra, revealing the significantly higher degree of fatty acid-related spectral features in ATR FT-IR spectra. Partial least squares (PLS)-based multivariate regression equations were established by relating ATR FT-IR spectra to fatty acid reference concentrations, obtained with gas chromatography-mass spectrometry (GC-MS). Good predictions were achieved for the most important fatty acid sum parameters: saturated fatty acids (SAT, R(2)(CV) = 0.94), monounsaturated fatty acids (MONO, R(2)(CV) = 0.85), polyunsaturated fatty acids (PUFA, R(2)(CV) = 0.87), unsaturated fatty acids (UNSAT, R(2)(CV) = 0.91), short-chain fatty acids (SCFA, R(2)(CV) = 0.79), medium-chain fatty acids (MCFA, R(2)(CV) = 0.97), and long-chain fatty acids (LCFA, R(2)(CV) = 0.88). The PLS selectivity ratio (SR) was calculated in order to optimize and verify each individual calibration model. All mid-IR regions with high SR could be assigned to absorbances from fatty acids, indicating high validity of the obtained models.

Keywords

• Mid-infrared spectroscopy; attenuated total reflection; fatty acids; human milk; partial least squares regression