Abstract:
The purpose of the study was to assess potential
application of front face fluorescence spectroscopy as a
rapid and non-destructive technique to discriminate
between fats of animal and plant origin based on their fatty
acid profiles, and to predict concentration of fatty acids
from fluorescence spectra. Vitamin E emission spectra
(300–500 nm) of butterfat and vegetable oil samples were
recorded with excitation wavelength set at 295 nm. Fatty
acid composition of the samples was determined by gas
chromatography. Principal component analysis and partial
least squares regression analysis were applied to the gas
chromatography and fluorescence spectroscopy data. The
butter-fats and vegetable oils were discriminated based on
the total saturated and unsaturated fatty acids respectively.
Tocopherols and tocotrienols accounted for the variability
among various oils. A good prediction model was established
with R2 = 0.745–0.992 for saturated fatty acids. The
unsaturated fatty acids were characterized by low coefficients
of determination (R2\0.339). The fatty acid profiles
predicted from fluorescence spectra did not show
significant difference to those determined by gas chromatography
used as references. A good association was
established between the two data tables. The study
demonstrated great potential of front face fluorescence
spectroscopy to rapidly discriminate between fats of animal
and plant origin, and predict their saturated fatty acids
composition, which could in turn be used for detection of
milk fat adulteration with vegetable oil.
