Determination of the Compositional Differences in Organic and Conventional Milk using FTIR Spectroscopy

Abstract

The organic food production has become one of the most attention receiving methods over the past two decades. Previous investigations on the differentiation of milk from conventional and organic production regarding its content ingredients have been done by chromatographic and titrimetric methods that are more time-consuming than Fourier-transform infrared (FTIR) spectroscopy. However, contradictory results are reported in the literature about quality differences between organic and conventional foods. The aim of our research was to evaluate FTIR spectroscopy as a rapid method for the detection of organic milk adulteration. Hundred and eighty-five (98 organic, 87 conventional) pasteurized whole fat (3% fatty) milk samples were supplied by different pasteurized milk markets in Columbus, Ohio, USA. The spectra of 185 milk samples at 25±1°C appeared quite homogeneous upon visual inspection. Infrared spectra were recorded between 4,000 and 700 cm-1 at a resolution of 4 cm-1 on the Agilent Cary 630 FTIR spectrometer with Soft Independent Modeling of Class Analogies (SIMCA) to analyze the spectra. Results showed well-separated clusters allowing discrimination of conventional samples from organic milk according to fatty acid differentiation. FTIR spectrometer, when compared to other techniques, has the main advantage in allowing very rapid measurements and findings characterized by quick results and analyses in the dairy industry for economic adulteration of cow‘s milk.