Study by 31P NMR spectroscopy of the triacylglycerol degradation processes in olive oil with different heat-transfer mechanisms.

The thermal degradation of olive oil using conventional and microwave heating under the same experimental conditions were compared. A powerful identification and quantification technique based on 31P NMR has been developed to characterise the differences between the minor components including diacyl...

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Detalhes bibliográficos
Autores: Lucas-Torres Pérez, Covadonga, Pérez Martínez, Angel, Cabañas Galán, Beatriz, Moreno Moreno, Andrés
Tipo de documento: artigo
Data de publicação:2014
País:España
Recursos:Universidad de Castilla-La Mancha
Repositório:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/6697
Acesso em linha:http://hdl.handle.net/10578/6697
Access Level:Acceso aberto
Palavra-chave:Olive oil
Conventional heating
Triacylglycerol hydrolysis
Microwave dielectric heating
Diacylglycerol isomerisation
31 P NMR
Descrição
Resumo:The thermal degradation of olive oil using conventional and microwave heating under the same experimental conditions were compared. A powerful identification and quantification technique based on 31P NMR has been developed to characterise the differences between the minor components including diacylglycerol and free fatty acids in the heated samples. The 31P NMR spectra of the degraded olive oils, which contain single bondOH groups derivatised with a phosphorus reagent, showed that conventional heating is more detrimental to the oil than microwave technique. Conventional heating leads to a significant increase in the diacylglycerol and free fatty acid contents as well as in the number of degradation compounds, which damage the olive oil quality. However, the main process that takes place on using microwave heating is isomerisation between diacylglycerols, a change that could give a potential longer shelf life to the olive oil.