title: A microcalorimetry study on the oxidation of linoleic acid and the control of rancidity.
abstract: The oxidative deterioration of unsaturated lipids fatty acids is a great concern for the food industry as it is associated with the development of rancid off-odors and the reduction of food quality. This work describes the potential use of isothermal microcalorimetry to monitor the oxidation of linoleic acid, an important conjugated fatty acid responsible for the development of rancidity. The heat flow signal developed during the oxidation process reflects a multistep mechanism typical of radical chain reactions. From the analysis of the thermograms, it is possible to identify a period of the reaction that occurs with an order equal to 0.5. This period is correlated with the propagation period of the radical chain reaction. In addition, it allows detecting the early appearance of rancidity notes, as confirmed with the analysis of the samples headspace by Proton-Transfer-Reaction Mass Spectrometry (PTR-MS). The proposed approach was finally applied to compare the capacity of natural and synthetic antioxidants to inhibit the oxidation process of linoleic acid and the occurrence of rancidity. The results presented here show the advantages of microcalorimetry to study oxidation reactions and their control.
authors.affiliation: Free University of Bolzano, Faculty of Science and Technology, Piazza Università 1, 39100 Bolzano, Italy.
authors.forename: Nabil
authors.initials: N
authors.lastname: Haman
authors.affiliation: Free University of Bolzano, Faculty of Science and Technology, Piazza Università 1, 39100 Bolzano, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Romano
authors.affiliation: Free University of Bolzano, Faculty of Science and Technology, Piazza Università 1, 39100 Bolzano, Italy.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asaduzzaman
authors.affiliation: Free University of Bolzano, Faculty of Science and Technology, Piazza Università 1, 39100 Bolzano, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Ferrentino
authors.affiliation: Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach (FEM), via E. Mach 1, 38010 San Michele all'Adige, TN, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Biasioli
authors.affiliation: Free University of Bolzano, Faculty of Science and Technology, Piazza Università 1, 39100 Bolzano, Italy. Electronic address: matteo.scampicchio@unibz.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Scampicchio
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002151:Calorimetry; D002212:Capsicum / Q000737:chemistry; D063427:Food Quality; D019787:Linoleic Acid / Q000737:chemistry*; D010084:Oxidation-Reduction; D014835:Volatilization; D024502:alpha-Tocopherol / Q000737:chemistry
chemical_list: D000975:Antioxidants; D019787:Linoleic Acid; D024502:alpha-Tocopherol
keywords: Isothermal microcalorimetry; Linoleic acid; Oxidation; Proton transfer reaction mass spectrometry (PTR-MS); Rancidity