Method for determining oxidation of vegetable oils by near‐infrared spectroscopy

Abstract

Use of near-infrared (NIR) transmittance spectroscopy for rapid determination of the oxidation level in soybean oils (SBO) was investigated, and calibrations were developed for quantitative determination of peroxide value (PV), conjugated diene value (CD), and anisidine value (AV) of SBO. Partial least squares (PLS) regression and forward stepwise multiple linear regression were used to develop calibration models from spectral data in log 1/T, first derivative and second derivative of log 1/T formats for both 1-and 2-mm path lengths. The models were validated by comparing NIR results from independent sample sets to the values obtained by official methods. The spectral region from 1100 to 2200 nm was best for measuring oxidation when using a 2-mm path length. PLS regression using first-derivative spectra gave the best results for PV. For the validation sets, linear relationships were obtained for PV (r = 0.99), and CD (r = 0.95), compared with accepted reference procedures. However, measurement of AV by NIR was less successful than measurement of the other two indices of oxidation, especially for an external validation sample set. Results obtained in this study indicate that NIR spectroscopy is a useful technique for measuring oxidation in soybean oil.Paper no. J9687 in JAOCS 78, 495-502 (May 2001).

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

“…The SECV values obtained for the universal model were slightly higher to those obtained for individual oils with SECV ranging from 0.7 to 0.9 meq/kg (data not shown). Yildiz and others [40] reported PLS regression models for determining oxidation of soybean oils by near-infrared transmittance spectroscopy gave correlation coefficients (r) of 0.99 and SEP of 0.72-0.76 meq/kg. The PLSR models developed from spectra collected using the benchtop systems provided similar SECV for estimation of FFA (0.05%), while the portable handheld unit gave higher SECV (0.09%).…”

NIR spectrometric determination of quality parameters in vegetable oils using iPLS and variable selection

“…In fact, the NIR spectrum comprises a complex overlapping of various combinations and overtones of fundamental vibrational transitions (Bokobza, 1998;Pasquini, 2003;Workman, 1996), which constitutes a significant challenge for multivariate calibration. Yildiz, Wehling, and Cuppett (2001) employed partial least squares (PLS) regression and forward stepwise multiple linear regression for NIR determination of peroxide, conjugated diene, and anisidine values in soybean oils. Good results were reported for peroxide and conjugated diene values, with correlation coefficients of 0.99 and 0.95, respectively.…”

Rapid Determination of Degradation in Frying Oils with Near‐Infrared Spectroscopy

“…In general, the tested samples had a wider range of FFA and CDA than was used in previous work [9,11], however the range of TPM was narrower. Reflectance NIRS is a reliable, accurate and fast technique to determine the FFA, TPM, and CDA concentrations in actual frying oils during lengthy use.…”