Shelf life extension of Merluccius hubbsi burgers using nanoemulsion with oregano essential oil

NEPOTE V.; ASENSIO C.; GROSSO N. R.; HUANG, Q.

Chicago

Congreso; IFT Annual Meeting; 2018

Introduction:Hake (Merluccius hubbsi) is the dominant demersal fish. Fishes are a rich source of omega-3 and 6, but they oxidized rapidly. Also, they deteriorate rapidly due to a variety of biochemical and microbial breakdown mechanisms. Oregano essential oils (OEOs) are natural preservatives. Nanoemulsions (NE) are used to encapsulate and deliver lipophilic ingredients. The objective of this study was to evaluate the preservative effects of OEO-NE on lipid deterioration and microbial spoilage of hake burgers during storage.Methods:Fish burgers (FB) treatments were prepared: control without any addition (C-FB), FB with EO (EO-FB), FB with NE-EO (NEEO-FB), and FB with Blank-NE (BNE-FB). Oregano EO and NE-EO were added at 0.02% (p/p). Fatty acids (CG-MS), volatile compounds (SPME, CG-MS), total volatile basic nitrogen (TVBN), and microbial count were measured every 3 days during storage (15 days at 4 °C). ANOVA and DCG multiple range test were used for statistical analysis. Significance:The preserving activity of OEO is well known. However, it is susceptible to degradation by external factors. Moreover, its direct incorporation into food products is limited because of its hydrophobicity. To include the OEO into a stable NE helps to protect and deliver it into the food. Also, this procedure allows to increase the distribution of the active compounds in the food matrix. Results:After 14 days, significant differences were detected (p≤0.01). C-FB exhibited the lowest amounts of 18:3n-3 (0.74%), 18:3n-6 (3.3%), 20:4 (0.54%), and 22:6 (13.6%) whereas EO-FB and NEEO-FB had the highest content of EPA (19.18% and 19.84%, respectively) and DHA (10.8% and 11.09%, respectively). On storage last day, BNE-FB and C-FB showed significantly higher content of nitrous oxide, dimethyl and trimethylamine than NEEO-FB and EO-FB. NEEO-FB had the lowest microbial count (7 log CFU/g after 14 storage days). The peak number and amount from EO volatile compounds released from EONE-FB, was less than in other treatments, suggesting a better interaction of EO compounds with the food matrix when it was incorporated as an NE. The inclusion of OEO into a NE improves its preserving activity when it is used in hake fish burgers.