Determination of the total unsaturation in vegetable oils by Fourier transform Raman spectroscopy and multivariate calibration

In this paper multivariate calibration was used in conjunction with NIR-Fourier transform Raman spectroscopy for determination of the total degree of unsaturation in vegetable oils. For this purpose, different vegetable oils and some mixtures were employed as calibration standards. A calibration model based on partial least squares (PLS) was constructed and used to analyse oils with iodine values ranging from 17 to 130. This methodology is rapid, simple and can be easily used in quality control laboratories or to monitor industrial process on line. (C) 2001 Elsevier Science B.V. All rights reserved.2619910

Multivariate quality control applied to detect the soybean oil oxidation using Fourier transform infrared spectroscopy

Multivariate quality control was used in conjunction. with Fourier transform infrared spectroscopy to detect the oxidation process in soybean oils. The multivariate approach was abased on principal component analysis (PCA) to develop two control charts: a T-2 chart using the most significant principal components and a Q chart with the remaining PCs hot used in the first one. From these-two charts it was possible to identify oxidation levels in oil samples which were out of the pattern normally present in edible soybean oils.35572973

Simultaneous determination of vitamins C, B6 and PP in pharmaceutics using differential pulse voltammetry with a glassy carbon electrode and multivariate calibration tools

In this work, the artificial neural networks (ANN) and partial least squares (PLS) were applied to data obtained by differential pulse voltammetry for the determination of vitamins in synthetic and pharmaceutical samples. For calibration purposes, both synthetic and commercial samples were employed as standards. From the results it was possible to verify that ANN is the best method for modeling the data due to the fact that interactions among electro-active components result in non-linear response on the glassy carbon electrode. The results achieved for the determination of vitamins in pharmaceutical samples using ANN method provided a maximum value for relative error of 0.40% for VC, 8.3% for VPP and 9.1% for VB6. The proposed methodology is simple, rapid and can be easily used to control quality laboratories as an alternative analysis method. (c) 2004 Elsevier B.V. All rights reserved.381949

Raman Spectroscopy as a Rapid Tool for Quantitative Analysis of Butter Adulterated with Margarine

Butter adulteration with margarine continues to be a threat for consumers; therefore, new rapid analytical tools are needed for quality control/quality assurance purposes. In this study, we used Raman spectroscopy coupled with partial least squares regression to quantify butter adulteration with margarine. The main difference between Raman spectra of butter and margarine comes from two bands associated to C=C double bond (1656 and 1268 cm(-1)) and the band associated to phospholipids' choline group (973 cm(-1)). The intensity of these peaks decreases with a decreasing margarine content. The coefficient of determination (R (2) = 0.994) and root-mean-square error of prediction (RMSEP = 2.754) display very good overall model performance. The sample preparation procedure that we employed was notably simplified compared to previous studies. This confirms that Raman spectroscopy can be effectively applied to quantify butter adulteration with margarine and further indicates that simplification of the analysis procedure is possible. These results could aid the efforts for implementation of this technique in routine rapid quality analysis of butter