Profile of Fatty Acids and Spectroscopic Characteristics of Selected Vegetable Oils Extracted by Cold Maceration

Abstract

Biodiesel has become more attractive material for its properties such as biodegradability, renewability and very low toxicity of its combustion products. A higher quality of this fuel is essential in its potential commercialization. Analytical methods used in biodiesel analysis are constantly refined. The most popular analytical techniques include chromatography and molecular spectroscopy. The ATR-FTIR spectroscopy is one of the most important methods of spectroscopy. This paper presents the results of studies on selected oils of natural origin using ATR-FTIR infrared absorption spectroscopy. Three types of oils from pumpkin seeds and winter rapeseed were analysed. The main fatty acids were also determined in all the samples.

Analysis of the Content of Fatty Acid Methyl Esters in Biodiesel by Fourier‐Transform Infrared Spectroscopy: Method and Comparison with Gas Chromatography

“…This analytical method requires previous sample treatment, tedious calibrations, long analysis times, and it is an expensive technique, among other disadvantages (Soares et al, ). Recently, less complicated analytical methods, such as nuclear magnetic resonance (NMR) or infrared spectroscopy (IR), have been developed for the characterization of oils and biodiesel samples (Adewale et al, ; Alonso et al, ; Aziziana and Kramer, ; Beltrán Sanahuja et al, ; Cruz et al, ; Dubé et al, ; Forfang et al, ; Guillén et al, ; Gelbard et al, ; Jin et al, ; Kachel et al, ; Kachel‐Jakubowska et al, ; Kollar et al, ; Matwijczuk et al, ; Mei Han and Chee Liang, ; Monteiro et al, ; Morgenstern et al, ; Oliveira et al, ; Siatis et al, ; Vrtiška and Šimáček, ), although some of them require costly equipment and analysis.…”

“…Specifically, the use of noninvasive and chemical free methods, such as FTIR, Fourier‐transform mid‐infrared (FTI‐MIR) and Fourier‐transform near‐infrared (FT‐NIR) spectroscopies, for the determination of physical and chemical characteristics of oils and fats have been developed. For example, Beltrán Sanahuja et al () studied the oxidative stability of four almond oils by the ATR‐FTIR technique, Adewale et al () used FT‐NIR for determining the free acid content and the iodine value of waste animal fat blends, Alonso et al () used FTIR to analyze the total trans fatty acid content of several edible fats and neat fats, Aziziana and Kramer () developed a method for the classifying and quantifying the fatty acids composition of fats and oils using FT‐NIR, Kachel et al () analyzed fatty acids profile of oils from pumpkin seeds and winter rapeseed with the FTIR spectroscopy method and Forfang et al () introduced FTIR spectroscopy as a tool for monitoring lipid extraction efficiency in fungal biomass; the presence or absence of lipid bands in the IR spectrum of the biomass after extraction can function as a measure for the efficiency of the extraction method. Although the FTIR technique has been used for the characterization of oils and fats as well as for determining chemical parameters, there are few studies focused on the determination of biodiesel (no diesel/biodiesel blend) obtained from the oil transesterification reaction using FTIR spectroscopy (Matwijczuk et al, ; Siatis et al, ).…”

Seed Lipid Composition of New Hybrids of Styrian Oil Pumpkin Grown in Poland

“…Linoleic acid predominates in the fatty acid composition, which accounts for 31 to 66% of all fatty acids. In addition to this acid, pumpkin seed lipids also contain significant shares of oleic acid (15-49%) and palmitic acid (10-13%) [11][12][13]. Variation in fatty acid composition of pumpkin seeds highly depends on climatic conditions.…”

Investigations on Storage and Oxidative Stability of Biodiesel from Different Feedstocks Using the Rancimat Method, Infrared Spectroscopy, and Chemometry

“…Figure A shows absorption bands characteristic of intense axial deformation of the group CO (carbonyl) and an average axial absorption of C–O (ester) at 1753 and 1220 cm –1 , respectively. It is also possible to observe bands attributed to the axial deformation of the C–H (sp 3 ) bond at 2930–2856 cm –1 , confirmed by the band around 1380 cm –1 derived from the symmetric angular deformation of the C–H bond of the methyl group and another at 720 cm –1 attributed to the out-of-plane asymmetric angular deformation of σ (sp 3 -s) C–H. , It was not possible to verify signals corresponding to the antioxidant in the biodiesel spectrum. However, a small band appears at approximately 1625 cm –1 when biodiesel is subjected to external factors such as the presence of light.…”