Application of a Handheld Portable Mid‐Infrared Sensor for Monitoring Oil Oxidative Stability

Abstract

This study evaluated the capabilities of a handheld mid-infrared (MIR) spectrometer combined with multivariate analysis to characterize oils, monitor chemical processes occurring during oxidation, and to determine fatty acid composition. Vegetable oils (corn, peanut, sunflower, safflower, cottonseed, and canola) were stored at 65°C for 30 days to accelerate oxidation reactions. Aliquots were drawn at 5 day intervals and analyzed by benchtop and portable handheld mid-infrared devices (4,000-700 cm -1 ) and reference methods (IUPAC 2301 [1], 2302 [1]; AOCS Cd 8-58 [2]; and Shipe 1979 [3]). PLSR and soft independent modeling of class analogy (SIMCA) models were developed for oil classification and estimation of oil stability parameters. Models developed from MIR spectra obtained with a benchtop spectrometer equipped with a 3-bounce ATR device resulted in superior discriminative performances for classifying oils as compared to those obtained from handheld spectra (singlebounce ATR). Models developed from reference tests and handheld spectra showed prediction errors (SECV) of 1 meq/kg for peroxide value, 0.09% for acid value and 2% for determination of unsaturated fatty acids in different oils. Spectral regions *3,012-2,850 cm -1 (C-H stretching bands/shoulders of fatty acids), *1,740 cm -1 (C=O stretching of esters), and *1,114 cm -1 (-C-O stretching) were found to be important for prediction. Handheld-FTIR instruments combined with multivariate-analysis showed promise for determination of oil quality parameters.Portability and ease-of-use makes the handheld device a great alternative to traditional methods.

A Simple and Portable Screening Method for Adulterated Olive Oils Using the Hand‐Held FTIR Spectrometer and Chemometrics Tools

“…An oil sample can be measured directly and quickly, then much information about the sample can be extracted from the spectrum by manual interpretation or chemometrics tools. Therefore, FTIR spectroscopy has been widely utilized for the quality assessments of edible oils, including the authentication (Gurdeniz, Ozen, & Tokatli, 2010;Javidnia, Parish, Karimi, & Hemmateenejad, 2013), the adulteration screening (Oussama, Elabadi, Platikanov, Kzaiber, & Tauler, 2012;Sun, Lin, Li, Shen, & Luo, 2015), and the determination of free fatty acids (Li, Garcia-Gonzalez, Yu, & van de Voort, 2008;Mahesar, Sherazi, Khaskheli, Kandhro, & Uddin, 2014), trans fatty acids (Mossoba, Milosevic, Milosevic, Kramer, & Azizian, 2007;Sherazi et al, 2009; Tyburczy, Mossoba, & Rader, 2013), peroxide values (Allendorf, Subramanian, & Rodriguez-Saona, 2012;Aykas & Rodriguez-Saona, 2016), cloud points (Setiowaty & Man, 2004), and other physical and chemical parameters (Luna, da Silva, Ferre, & Boque, 2013;Nunes, 2014).…”

“…Because the timeliness has been more and more important for food quality control, the portable FTIR methods are required for the rapid and field assays of olive oils. Some hand-held FTIR spectrometers have been reported for the identification and parameter determination of edible oils (Allendorf et al, 2012;Aykas & Rodriguez-Saona, 2016;Birkel & Rodriguez-Saona, 2011;Li et al, 2008), but not used to screen the adulterated olive oils.…”

Prediction of various chemical parameters of olive oils with Fourier transform infrared spectroscopy

“…FTIR spectroscopy has already been used in peroxide value determination for different vegetable oils (Allendorf, Subramanian, & Rodriguez-Saona, 2012) and in the quantification of fatty acids and triacylglycerols of olive oils (Galtier et al, 2008).…”

At‐line monitoring of industrial frying processes using ATR‐FTIR‐PLS method

“…The absorbance at approximately 3.008 cm −1 is characteristic of C‐H vibrations in the cis bonds of unsaturated fatty acids (Pinto, Locquet, Eveleigh, & Rutledge, ; Talpur et al, ). Peaks at 1.465 and 1.375 cm −1 represent the –CH 2 and –CH 3 bond vibrations of the aliphatic groups (Allendorf, Subramanian, & Rodriguez‐Saona, ). The peak at 1.236 cm −1 represents the vibrations of the –CH 2 clusters in trans fatty acids (Talpur et al, ).…”