Discrimination of n-3 Rich Oils by Gas Chromatography

Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived from animals is a very important though much neglected area that was emphasized more than 100 years ago. In this study the potential of gas chromatography (GC) for discriminating full fatty acid methyl ester (FAME) profiles from fish (cod liver and salmon) and marine mammal (seal and whale) oils is evaluated by means of principal component analysis (PCA). The FAME profiles from plant oils such as rapeseed, linseed and soy oils and seven different brands of n-3 supplements are also used in the discrimination process. The results from the PCA plots can reliably distinguish between plant, n-3 supplements, fish and marine mammal oils. By removing the contribution of the n-3 supplements and plant oils it is possible to discriminate between types of fish and marine animal oils. GC offers a rapid, simple and convenient means of discriminating oils from different species, brands and grades

Application of FTIR spectroscopy for the determination of virgin coconut oil in binary mixtures with olive oil and palm oil.

Rapid Fourier transform infrared (FTIR) spectroscopy combined with attenuated total reflectance (ATR) was applied for quantitative analysis of virgin coconut oil (VCO) in binary mixtures with olive oil (OO) and palm oil (PO). The spectral bands correlated with VCO, OO, PO; blends of VCO and OO; VCO and PO were scanned, interpreted, and identified. Two multivariate calibration methods, partial least square (PLS) and principal component regression (PCR), were used to construct the calibration models that correlate between actual and FTIR-predicted values of VCO contents in the mixtures at the FTIR spectral frequencies of 1,120–1,105 and 965–960 cm−1. The calibration models obtained were cross validated using the “leave one out” method. PLS at these frequencies showed the best calibration model, in terms of the highest coefficient of determination (R 2) and the lowest of root mean standard error of calibration (RMSEC) with R 2 = 0.9992 and RMSEC = 0.756, respectively, for VCO in mixture with OO. Meanwhile, the R 2 and RMSEC values obtained for VCO in mixture with PO were 0.9996 and 0.494, respectively. In general, FTIR spectroscopy serves as a suitable technique for determination of VCO in mixture with the other oils

The Application of Classical Least Square Algorithm in the Quantitative Analysis of Lime in Wheat Flour by ATR-MIR Spectroscopy

Part 1: GIS, GPS, RS and Precision FarmingInternational audienceIn this thesis, classical least square (CLS) regression was applied in the attenuate total reflection mid-infrared (ATR-MIR) spectra data processing of lime in wheat flour to develop the corrected peak height model of the raw spectra, the corrected peak area model of the raw spectra, the corrected peak height model of the 2nd derivative spectra and the corrected peak area model of the 2nd derivative spectra respectively. The result indicated that the correlation coefficients of the four models mentioned above are 0.9648, 0.9696, -0.9646 and -0.9599 respectively. F-test result indicated that a very remarkable correlation exists between the estimated and specified values of the calibration set and external validation set. The detection limits of the four models mentioned above are 3.51 %, 3.21 %, 3.51 % and 3.69 % respectively, which can fulfill the demand for the rapid quality safe screening of wheat flour in the market. This method, to some extent, can provide some references for not only the design and manufacturing of the special MIR instrument for the quality safe control of wheat flour in the market but also the quantitative determination of banned additives in wheat flour

Dragon fruit (Hylocereus spp.) seed oils: their characterization and stability under storage conditions

Oil was extracted from the seeds of white-flesh and red-flesh dragon fruits (Hylocereus spp.) using a cold extraction process with petroleum ether. The seeds contained significant amounts of oil (32–34 %). The main fatty acids were linoleic acid (C18:2, 45–55 %), oleic acid (C18:1, 19–24 %), palmitic acid (C16:0, 15–18 %) and stearic acid (C18:0, 7–8 %). The seed oils are interesting from a nutritional point of view as they contain a large amount of essential fatty acids, amounting to up to 56 %. In both dragon fruit seed oils, tri-unsaturated triacylglycerol (TAG) was mainly found while their TAG composition and relative percentage however varied considerably. Therefore, they showed a different melting profile. A significant amount of total tocopherols was observed (407–657 mg/kg) in which the a-tocopherol was the most abundant (*72 % of total tocopherol content). The impact of storage conditions, cold and room temperatures, on the oxidative stability and behavior of tocopherols was monitored over a 3-month storage period. During storage, the oxidative profile changed with a favorably low oxidation rate (*1 mequivO2/week) whilst tocopherols decreased the most at room temperature. After 12 weeks, the total tocopherol content, however, still remained high (65–84 % compared to the initial oils). Hereto, the dragon fruit seed oils can be considered as a potential source of essential fatty acids and tocopherols, with a good oxidative resistance