Elaboration and evaluation of chicken burger patty added with oregano extract as a natural antioxidant

Abstract

This study aimed to evaluate chicken burger patties added with oregano extract as a natural antioxidant. A hydroalcoholic extract of dehydrated oregano was prepared. The lyophilized extract was evaluated for antioxidant activity by the Folin-Ciocalteu, DPPH, FRAP, and ABTS methods. Chicken burger patty formulations were prepared with the addition of lyophilized oregano extract at different concentrations: 0.00% (control formulation - C), 0.25% (NA1), 0.50% (NA2), 0.75% (NA3), and a formulation with the addition of 0.25% sodium erythorbate, a synthetic antioxidant (SA). The burger patties were evaluated for pH, water activity, lipid oxidation, yield, shrinkage, color, and texture. The oregano extract showed 182.38 g GAE g−1 of reducing capacity, 2531.13 mmol Trolox g−1 for antioxidant activity by FRAP, 2.16 mmol Trolox g−1 for ABTS, and an EC50 for DPPH of 33.88 g extract g−1 DPPH. The addition of oregano extract did not change the parameters of pH, water activity, shrinkage, and texture profile of the burger patties. The burger patties added with 0.50% (NA2) and 0.75% (NA3) of oregano extract were darker, less reddish, and more yellowish than C, NA1, and SA burger patties. Formulations NA1, NA2, NA3, and SA did not differ from each other regarding lipid oxidation at 60 days of storage, but with values significantly lower than formulation C (without antioxidants). Furthermore, an increase in TBARS values was observed during the storage period for formulations C and SA, which was not observed for formulations with the addition of natural antioxidants (NA1, NA2, and NA3). Oregano extract showed antioxidant properties evaluated by different methods, demonstrating the potential to be used as a substitute for synthetic antioxidants in foods. The addition of 0.25% of oregano extract in chicken burger patties led to lower lipid oxidation without compromising color, texture, and yield parameters, being considered the ideal concentration for application.