The objective of the present experiment was to evaluate the effects of including the essential oil of copaiba and oregano as a possible replacement for synthetic butylated hydroxytoluene (BHT) additives in fish meat ball. PH, cooking loss, texture, color, sensory acceptability and chemical composition were evaluated. The addition of oregano essential oil had an effect on the color of the fish meat ball (P <0.05), showing better results for a * and Hue compared to BHT, and b * and Croma compared to the control (COM). In addition, the essential oils of copaiba and oregano showed the lowest water losses by cooking and the essential oil of oregano improved the aroma of the fish meat ball (P <0.05). The treatments had no effect (P> 0.05) on the chemical composition of the fish meat ball. The essential oils of copaiba and oregano are promising natural antioxidants to increase the useful life of fish by-products, in addition to being a viable solution to replace the synthetic antioxidant BHT, bringing benefits to its commercialization.

The preservative effect of the addition of different essential oils (copaiba and oregano) on meat quality parameters and sensorial acceptability was analyzed for fresh ground beef patties over 21 days of display. Five treatments were assessed: control (CON) without antioxidants; addition of the synthetic additive butylated hydroxytoluene (BHT); addition 0.05% of copaiba essential oil (CEO); 0.05% of oregano essential oil (OEO); or blend of 0.025% copaiba and 0.025% oregano essential oils (BEO). The lowest cooking losses and greatest tenderness (P <0.05) were reached with the blend (BEO). The inclusion of oregano essential oil presented a more intense chroma (P <0.05), with the best color retained during display. Oregano essential oil (OEO) and the blend (BEO) showed the highest antioxidant activity, reducing the lipid oxidation of beef patties during display (P < 0.05). Consumers preferred the odor of beef patties with essential oils (OEO and BEO) to the CON; however, the flavor from OEO had the lowest acceptability and the worst scores for overall acceptability (P < 0.05). Patties with the blend addition (BEO) were the best scored on overall acceptability assessments. In conclusion, the oregano and copaiba essential oils blend had a good preservative effect on fresh beef patties during display and increased sensory acceptability of the product, thus being a possible alternative for replacing synthetic compounds in processed foods.