Determination by fourier transform Raman spectroscopy of conjugated linoleic acid in I2-photoisomerized soybean oil.
The potential of Fourier transform (FT)-Raman spectroscopy to quantify the total conjugated linoleic acid (CLA) content was evaluated to find a technique for the routine control of CLA synthesis by chemical procedures. The calibration and validation samples were obtained by photoisomerization of linoleic acid contained in soybean oil. The catalyst was iodine (I(2)), and the light source was the green line (514.5 nm) of an argon ion laser. The criteria to select the best partial least-squares (PLS) calibration model were a low standard error of prediction (SEP), a high correlation coefficient (R), and the selection of relevant variables of the Raman spectrum to reduce spectral interferences. The total CLA content of the 22 samples ranged from 0.05 to 3.28% of total lipids. The best PLS calibration model was obtained with three optimal factors, a SEP of 0.22, and a R of 0.97. This calibration model was obtained after baseline correction of the CC stretching region (1642-1680 cm(-1)), which contained sufficient spectral information for reliable CLA quantification.
Bernuy
Bruno
B
Unite de Biochimie de la Nutrition, Faculte d'Ingenierie Biologique, Agronomique et Environnementale, Universite Catholique de Louvain (UCL), Croix du Sud 2 (bte 8), 1348 Louvain la Neuve, Belgium.
Meurens
Marc
M
Mignolet
Eric
E
Turu
Christine
C
Larondelle
Yvan
Y
D055598:Chemical Phenomena / Q000528:radiation effects; D007455:Iodine / Q000737:chemistry*; D007536:Isomerism; D008027:Light; D044243:Linoleic Acids, Conjugated / Q000737:chemistry*; D010777:Photochemistry; D013024:Soybean Oil / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
D044243:Linoleic Acids, Conjugated; D013024:Soybean Oil; D007455:Iodine