Thermal degradation and isomerisation kinetics of triolein studied by infrared spectrometry and GC–MS combined with chemometrics

Abstract

Triolein, a triglyceride containing oleic acid as the only acid moiety in the glyceride molecules has been isothermally treated at 280, 300, and 325 o C in glass vials under nitrogen atmosphere. The products formed during the thermal treatment at each temperature have been analysed both by infrared spectrometry and GC-MS. The GC-MS analysis was performed after derivatisation of the fatty acids into their methyl esters (FAMEs).Chemometric tools were used in determining the concentrations of the main products namely triolein and trieaidin in the thermally treated mixtures. The concentration profiles of the trielaidin formed during thermal treatment at the above three temperatures were used in determining activation energy for the cis-trans isomerisation of triolein The combined analysis reveals that the thermal treatment induces not only cis-trans isomerisation but also fission and fusion in the molecules. Furthermore, migration of the double bond in oleic and elaidic acids forming cis and trans isomers of the 18:1 acid was also observed. The heat induced isomerisation in triolein follows a zeroeth order reaction with an activation energy 41±5 kcal/mol.

Molecular Structure and Electronic Properties of Triolein Molecule under an External Electric Field Related to Streamer Initiation and Propagation

“…A scale factor of 0.960 was employed with the B3LYP/6-31G* scheme to address the fundamental error raised in an earlier work [29]. The results are listed in Table 1 together with previously published experimental data [30,31]. The vibrational frequencies obtained for C=O stretching were 1775.7 cm −1 , 1778.2 cm −1 , and 1784.9 cm −1 from C12=O13, C14=O15, and C16=O17, respectively.…”

“…1 Scale factor data are taken from [29]. 2,3 Experimental data are taken from [30,31], respectively.…”

New insights into the surface functionalities and adsorption evolution of water molecules on silica gel surface: A study by second derivative near infrared spectroscopy

“…None of the other research work used any other techniques to resolve peaks to give better understanding and interpretations of the absorptions in the infrared spectra of silica gel samples. Second derivative profiles of the infrared and near infrared spectra have revealed some important features in the spectra for interpretation purposes [22][23][24]. Use of second derivative techniques in qualitative and quantitative analysis in near infrared spectroscopy has become very common.…”

Thermally Induced Isomerisation Kinetics of the 9c11t and 10t12c Conjugated Linoleic Acids in Triacylglycerols as Studied by FT-IR Spectrometry Aided by Gas Chromatography

“…Several glass ampoules of length 4 cm were made from glass tubes of 1.5 mm internal diameter and a wall thickness of 1 mm. Heating in micro size glass ampoules is an advantage experimentally [25]. The glass tubes attain the temperature of reaction within a short time and cools very fast when the tubes are removed from the oven.…”