Trans determination of edible oils by fourier transform near‐infrared spectroscopy

Abstract

A generalized partial-least-squares calibration for determination of the trans content of edible fats and oils by Fourier transform near-infrared (FT-NIR) spectroscopy using 8-mm disposable glass vials for sample handling and measurement was developed. The trans contents of a broad range of oils were determined using the American Oil Chemists' Society single-bounce horizontal attenuated total reflectance (SB-HATR) mid-infrared spectroscopic procedure, these trans reference data were used in the development of the generalized FT-NIR calibration. Additional refined and product-specific calibrations were also developed, and all the calibrations were assessed for their predictive capabilities using two sets of validation samples, one comprising a broad range of oil types and the other restricted to oils with specific characteristics. The FT-NIR trans predictions obtained using the generalized calibration were in good agreement with the SB-HATR results; the values were accurate and reproducible to within ±1.1 and ±0.5% trans, respectively, compared to a reproducibility of ±0.40% trans obtained for the SB-HATR method. The accuracy of the predictions obtained from the generalized FT-NIR calibration for particular oil types was not significantly improved by supplementing the base training set with samples of these specific types. Calibrating only these oil types did, however, produce a substantial improvement in predictive accuracy, approaching that of the SB-HATR method. These product specific calibrations produced serious predictive errors when nonrepresentative samples were analyzed. The incorporation of a supplementary discriminate analysis routine was found to be a powerful safeguard in flagging nonrepresentative samples as outliers and could also be used to select the calibration most appropriate for the characteristics of the sample being analyzed. Overall, it was concluded that FT-NIR spectroscopy provides a viable alternative to the SB-HATR/mid-Fourier transform infrared method for trans determination, making use of more industrially robust instrumentation and equipped with a simpler sample handling system. FIG. 4. A cross-validation plot of FT-NIR trans predictions obtained using the Cal-1 vs. the SB-HATR trans reference values. See Figure 2 for abbreviation.

A rapid method for the quantification of fatty acids in fats and oils with emphasis on trans fatty acids using fourier transform near infrared spectroscopy (FT‐NIR)

“…FT-NIR is a nondestructive method applied directly to fats or oils (neat) and has been used to a limited extent in measurements of fats and oils, primarily to quantify selective FA or groups of FA, such as trans and unsaturated FA (38)(39)(40)(41)(42)(43). The limited application appears to be based on the general assumption that the FT-NIR signals were too weak and broad, and lacked the sensitivity required for a detailed FA determination.…”

“…In addition, FT-NIR has the same advantages as FTIR over their respective dispersivebased spectrometries (24,34). Although it is not an official method of trans FA determination, FT-NIR has been evaluated for determination of the total cis and trans contents, iodine values, and saponification numbers of several fats and oils (38,39). Chemometric analysis was used because the FT-NIR absorption spectra consist of broad and overlapping overtones of fundamental FTIR bands that cannot be resolved by means of traditional univariate analysis techniques.…”

Vibrational Spectroscopy of Food and Food Products

“…34,120 These methods are analogous to the MIR methods described in Section 2.1.2 but offer the advantage of greater ease of sample handling. For example, for the determination of IV 118 and trans content, 119 good analytical accuracy and precision were obtained by analyzing fats and oils in disposable glass vials placed in a thermostated holding block. Several groups have also used NIR spectroscopy as a tool for the discrimination of different types of fats and oils, 118,121 -123 one of the objectives of this work being to evaluate the potential utility of NIR spectroscopy for detecting adulteration of these types of products.…”

RETRACTED ARTICLE: Investigation of Frying Oil Quality Using VIS/NIR Hyperspectral Analysis

“…Many studies have been conducted to investigate the potentials of spectroscopic methods to determine quality parameters in edible oils, these include determination of trans fat content and the peroxide value of edible oil using Fourier transform near-infrared spectroscopy (FT-NIR) [5,6]. [7] used the spectra within the range of 4,000-850 cm -1 with a FTIR attenuated total reflectance spectroscopy (FTIR-ATR) to differentiate among good, marginal, and unacceptable oils.…”