Automated quantitative analysis of isolated (nonconjugated) trans isomers using fourier transform infrared spectroscopy incorporating improvements in the procedure

Abstract

A method for determining the isolated (nonconjugated)trans isomer content of fats and oils was developed using Fourier Transform Infrared Spectroscopy (FTIR), which permits automatic sample analysis and calculation of percenttrans content. Integrated band areas were used as a measure of the intensity of the band associated with thetrans C=C double bond. Measured band areas for samples with known percenttrans content were fit with a second order polynomial, resulting in a correlation coefficient of 0.99998 and a standard error of estimate of 0.11 over the range of 0 to 50%trans content. This technique also allows the analysis of neat samples, a significant improvement over current procedures in that it eliminates the need for dilution by volatile solvents and any attendant errors.

The Fatty Acid and Sterol Content of Food Composites of Middle-Aged Men in Seven Countries

“…The preparation of fatty acid methyl esters for gas chromatography in Finland was done according to Bannon et al (1982), and for the infrared spectrometry method according to IUPAC 2.301. Duplicate esters of the samples were analyzed as neat solutions according to Sleeter and Matlock (1989). For gas chromatography in Finland a Hewlett-Packard 5890 II was used, and the IR spectrophotometer was a Perkin-Elmer 16PC, Type FTIR.…”

Prediction of naturally-occurring, industrially-induced and total trans fatty acids in butter, dairy spreads and Cheddar cheese using vibrational spectroscopy and multivariate data analysis

“…Vibrational spectroscopy is based on quantum energy shifts when incident photons excite specific chemical bonds in sample material under reflection/transmission (IR) and anti-stokes/stokes scatteration (Raman) modes. Since the 1940s, IR spectroscopy has been used to determine trans content in edible fats and oils (AOCS, 1946;Firestone and LaBouliere, 1965;Dutton, 1974;Sleeter and Matlock, 1989). The American Oil Chemists' Society (AOCS) published official IR methods in 1999in , 2000in (AOCS, 1999in , 2000) but these methods are only suitable for edible oils and fats which are typically composed of a relatively small number of different fatty acids (approximately several dozen) compared to the over 400 in milk fat; they haven't achieved accurate prediction at low concentrations (<5% w/w of total fat) in complex matrices such as milk fat (Mossoba et al, 2011;Stefanov et al, 2011).…”

Olive Oil Analysis by Infrared and Raman Spectroscopy: Methodologies and Applications

“…Based on the information contained in the mid-infrared spectra, a series of methods has been developed to quantify the trans content (AOCS 1988;Belten et al 1988;Mossoba, Yurawecz & McDonald 1996;Ratnayake & Pelletier 1996;Sleeter & Matlock 1989;Ulberth & Haider 1992;van de Voort, Ismail & Sedman 1995), the cis content (van de Voort, Ismail & Sedman 1995), the peroxide content (van de Voort et a!. 1994b ), the aldehyde content in thermally stressed oils (Dubois et al 1996), and the free fatty acid content (Ismail et al 1993).…”