title: Deep-frying food in extra virgin olive oil: a study by (1)H nuclear magnetic resonance of the influence of food nature on the evolving composition of the frying medium.
abstract: Three series of fourteen deep-frying experiments on three foods of very different compositions were carried out using extra virgin olive oil as the original frying medium. The aim of the study was to establish how the nature of the food being fried influences the composition of the frying medium. The changes in the composition of the frying media referred to the evolution of molar percentage of the different kinds of acyl groups, as well as to the evolution of the concentration of newly formed compounds such as aldehydes, epoxystearyl groups, primary and secondary alcohols were monitored in a simultaneous way by (1)H NMR spectroscopy. Changes due to hydrolytic processes were also considered. In addition, the evolution of the Iodine Value and percentage in weight of polar compounds was also analysed. The influence of food lipids migration to the frying medium on the composition of this latter was evidenced.
authors.affiliation: Food Technology, Faculty of Pharmacy, Lascaray Research Center, University of the Basque Country (UPV-EHU), Paseo de la Universidad No. 7, 01006 Vitoria, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Martínez-Yusta
authors.affiliation: Food Technology, Faculty of Pharmacy, Lascaray Research Center, University of the Basque Country (UPV-EHU), Paseo de la Universidad No. 7, 01006 Vitoria, Spain. Electronic address: mariadolores.guillen@ehu.es.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Guillén
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D000818:Animals; D001939:Bread / Q000032:analysis*; D003296:Cooking; D004075:Diglycerides / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D008460:Meat / Q000032:analysis*; D000069463:Olive Oil; D010938:Plant Oils / Q000737:chemistry*; D020317:Salmo salar; D017747:Seafood / Q000032:analysis*; D013552:Swine
chemical_list: D000438:Alcohols; D000447:Aldehydes; D004075:Diglycerides; D004852:Epoxy Compounds; D000069463:Olive Oil; D010938:Plant Oils
keywords: Acyl groups; Alcohols; Aldehydes; Deep-frying; Degradation; Epoxides; Extra virgin olive oil; Food lipids migration; Frying media composition; Hydrolysis; Iodine Value; Percentage in weight of polar compounds