Assessment of Different Measurement Methods Using ¹H‐NMR Data for the Analysis of the Transesterification of Vegetable Oils

Abstract

In the present work we make assessments of the correlation of equations based on 1 H-NMR data for the analysis of FAME in 45 transesterification products with methanol from several vegetable oils (soybean, corn, sunflower, canola, linseed, cottonseed and jatropha). The products employed in this study were of high and low yield. A comprehensive approach to the applicability, advantages and limitations of employing NMR expressions is described. A new expression to determine the degree of unsaturation of combined and free fatty acids was found to be satisfactory when compared with the classic expression. Estimates of uncertainties for classic equations, which have been used to determine yield and degree of unsaturation, were proposed in the present work. The results show that either one or both of the expressions for estimating yields could not be satisfactorily used for products from linseed oil, and also indicate the possibility that products from cottonseed oil may also be exceptions. Both the equations were found to be satisfactory for the products obtained from the other oils (soybean, corn, sunflower, canola and jatropha), considering the uncertainties proposed in the present work.

Brown adipose tissue mapping in rats with combined intermolecular double‐quantum coherence and Dixon water–fat MRI

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1H NMR spectral analysis as a new aspect to evaluate the stability of some edible oils

“…1 H NMR has also been employed to estimate some physico-chemical analysis parameters in vegetable oils and their transesterificated products. Determination of the degree of unsaturation of combined and free fatty acids was found to be satisfactory when compared with the classical expression (Andrade et al, 2012). Determination of free fatty acids in pharmaceutical lipids by 1 H NMR and comparison with the classical acid value (AV) was achieved.…”

Non-Invasive Methods for Predicting the Quality of Processed Horticultural Food Products, with Emphasis on Dried Powders, Juices and Oils: A Review

“…Their model indicated that both methods (Classical and 1 H-NMR) exhibited a similar analytical performance. Andrade et al [ 127 ] assessed the presence of fatty acid methanol esters in different vegetable oil blends (e.g., soybean, corn, sunflower, canola, linseed, cottonseed, and jatropha) within a spectral wavelength of 200 MHz. The authors reported a chemical shift that is characteristic of the methoxyl groups in methyl esters.…”