Evaluation of the Performance of a Portable Mid‐Infrared Analyzer for the Rapid Determination of Total Trans Fat in Fast Food

Abstract

The performance of a novel, transmissionmode, portable, Fourier transform infrared (FTIR) analyzer was evaluated and compared to that of a benchtop attenuated total reflection (ATR)-FTIR spectrometer. The total concentration of trans fatty acids in the fat extracted from 19 representative fast foods was rapidly (\5 min) quantified in a single measurement after conversion to fatty acid methyl esters (FAME). While the FTIR determination is rapid, the time required for extraction and derivatization is not. For all extracts, the total trans FAME concentration varied from approximately 0.5 to 11 % (of total FAME) as determined using the portable FTIR analyzer. The trans fat contents (mean ± SD), expressed in grams per serving and calculated on the basis of total fat content and FTIR determination of trans fat content, were found to be 1.00 ± 0.42 for hamburgers, 0.67 ± 0.78 for chicken tenders, 1.00 ± 1.24 for French fries, and 0.27 ± 0.23 for apple pies. Determinations of total trans-unsaturated FAME were consistent with those obtained by use of ATR-FTIR and GC official methods (AOCS Cd 14e-09 and AOCS Ce 1j-07, respectively). These results indicate that the portable FTIR analyzer is suitable for the rapid and routine quantification of total trans fat measured as FAME prepared from fats extracted from fast foods.

Rapid Prediction of Low (<1%) trans Fat Content in Edible Oils and Fast Food Lipid Extracts by Infrared Spectroscopy and Partial Least Squares Regression

“…Total lipids were extracted from the homogenized fast food samples in duplicate according to Official Method 996.06 (AOAC, ), with modifications previously described (Mossoba et al., , Tyburczy et al., ). Briefly, each homogenized food test portion was thawed at approximately 15 to 18 °C in a water bath and accurately weighed to the nearest 0.001 g in a 125‐mL Wheaton storage bottle.…”

“…Calculations for the contents of individual FAs were performed using theoretical correction factors, relative to the internal standard tridecanoin (C13:0 triglyceride). The concentration of total TFA was calculated as the sum of all FAs containing one or more isolated trans double bonds, taken as the percentage of total FAs (Mossoba et al., ; Tyburczy et al., ).…”

“…For fast food lipid extracts, one spectrum was collected for each of the duplicate extracts, unless otherwise specified. Test portions of approximately 50 μL were analyzed with each instrument, after which, the ATR diamond crystal was cleaned by carrying out the 4‐step cleaning procedure described elsewhere (Mossoba et al., ).…”

“…However, the 2 most common analytical approaches for quantifying total TFAs in edible fats, oils, and foods are GC‐FID and FTIR. Comparisons of the advantages, limitations, and performance limits of these two analytical approaches have been reported elsewhere (Mossoba et al., ; Tyburczy, Mossoba, & Rader, ). GC‐FID has conventionally been used for TFA determinations because it provides FA composition including the contents of saturated and monounsaturated FA, which are required for nutrition labeling (Mossoba & Kramer, ).…”

Determination of <i>trans</i> Fat in Selected Fast Food Products and Hydrogenated Fats of India Using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) Spectroscopy

“…Total lipids were extracted from fast food samples according to AOAC official method 996.06 with slight modifications 16 . Test food samples were crushed and transferred into 250 mL RB.…”