Bakailao-gibel olio fresko eta oxidatuaren urdail-hesteetako in vitro digestioa: BSA eta BHTren propietate antioxidatzaileen eta azken honetatik eratorritako metabolitoen azterketa

Abstract

This study was aimed to investigate the effect of bovine serum albumin (BSA) protein and the phenolic antioxidant 2,6-di-tert-butyl-hydroxytoluene (BHT, additive E-321) on the oxidation reactions taking place during in vitro gastrointestinal digestion of fresh and oxidized cod liver oil. Likewise, the potential degradation of BHT under these conditions and transformation into different metabolites was addressed. The technique employed to study the nature and amount of lipid secondary oxidation products, as well as the BHT-metabolites of low molecular weight, present in the digestates was studied by Solid Phase Microextraction followed by Gas Chromatography/ Mass Spectrometry (SPME-GC/MS). Based on the abundances of 90 volatile compounds detected in the headspace of the digestates, it could be observed that both BSA and BHT had a clear antioxidant effect. In the conditions of this study, the former showed to be more effective than the latter, specially in the case of oxidized oil digestion. In addition, it was highlighted that BHT notably degraded during digestion of oxidized oil. As consequence, the main volatile metabolites 2,6-di-tert-butyl-4-hydroxy-4-methyl-2,5-cyclohexadien-1-one (BHT-OH), 2,6- di-tert-butyl-2,5-cyclohexadien-1,4-dione (BHT-Q) and 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO) increased.; Ikerketa honen helburua da behi-seroalbumina proteinak (BSA) eta 2,6-di-tert-butil-hidroxitolueno (BHT, E-321 gehigarria) antioxidatzaile fenolikoak bakailao-gibel olio fresko eta oxidatuaren in vitro digestioan gertatutako oxidazio erreakzioetan duten efektua aztertzea. Halaber, kondizio horietan gerta daitekeen BHTren degradazioa eta hori hainbat metabolito bihurtzea ere aztertu zen. Lipidoen oxidazio-produktu sekundarioen izaera eta kantitatea zein BHTren pisu molekular baxuko metabolitoak aztertzeko erabilitako teknika hau izan zen: Fase Solidoko Mikroerauzketa eta ondoren Gas- Kromatografia/ Masa-Espektrometria (SPME-GC/MS). In vitro digestioaren ondoren jasotako digestatoen buru-gunean aurkitutako 90 konposatu lurrunkorren ugaritasunetan oinarrituz, BSAk eta BHTek efektu antioxidatzaile argia zutela ikusi zen: lehena izan zen bietan eraginkorrena lan honen kondizioetan, batik bat oxidatutako olioaren digestioan. Bestalde, oxidatutako olioaren digestioan zehar BHT modu nabarmenean degradatu zela ikusi zen. Horren ondorioz, 2,6-di-tert-butil-4-hidroxi- 4-metil-2,5-ziklohexadien-1-ona (BHT-OH), 2,6-di-tert-butil-2,5-ziklohexadien-1,4-diona (BHT-Q) eta 3,5-di-tert-butil- 4-hidroxi- benzaldehidoa (BHT-CHO) metabolito lurrunkor nagusien handitzea gertatu zen.