Hake (Merluccius hubbsi) is the most important fish of Argentinean industry. The preservative effects of an oregano essential oil (EO) nanoemulsion (NE) on hake burgers (FB) during 15 days at 4°C were studied. Fatty acids determined by gas chromatography coupled with mass spectrometry (CG-MS), volatile compounds determined by solid phase microextraction (SPME) coupled with CG-MS, total volatile basic nitrogen (TVBN), and microbial count was measured. ANOVA and DCG tests were performed. After 14 days, significant differences were detected among samples (P ≤ 0.05). FB with EO (EO-FB) and FB with NE containing EO (NEEO-FB) had the highest content of EPA (eicosapentaenoic acid) (191.82 and 198.42 g kg À1 ) and DHA (docosahexaenoic acid) (107.97 and 110.87 g kg À1 , respectively). Also, NEEO-FB had the lowest microbial count (7 log CFU g À1 ). The incorporation of the oregano essential oil into a nanoemulsion improves the preserving activity in hake fish burgers.
Storage study and chemical analysis of stored hake burgersHakes (total 9 kgs) were purchased fresh from a local market. Pure EO, nanoemulsion containing EO (NE-EO) Oregano nanoemulsion: hake burger quality preserver C. M. Asensio et al. 150 Oregano nanoemulsion: hake burger quality preserver C. M. Asensio et al.