Efeito antioxidante do extrato de resíduos do processamento da acerola (Malpighia emarginata) na estabilidade oxidativa de hambúrguer de carne bovina

Abstract

Meat products are vulnerable to lipid oxidation, the main cause of unpleasant taste and odor development, reducing shelf life and leading to the formation of toxic compounds. The addition of antioxidants is a common practice to increase the stability of lipids present in these products, however, due to possible risks to human health, the interest in natural alternatives is increasing. This work aimed to evaluate the antioxidant effect of the extract of acerola (Malpighia emarginata) residues on the oxidative stability of beef hamburger and compare it with the synthetic antioxidant BHT (butyl-hydroxytoluene). Four extracts were prepared: aqueous, hydroethanolic, hydromethanolic and hydroacetonic, using the residues (peels and seeds) of acerola from a pulp processing industry in Fortaleza (CE). The extracts were analyzed for the content of phenolic compounds and antioxidant activity. The hydromethanolic extract was chosen for presenting the highest content of phenolic compounds and higher antioxidant activity. Four hamburger formulations were prepared: without added antioxidant - F1 (Standard Formulation); with added antioxidant BHT - F2; with added acerola extract containing 200 mg phenolics/kg burger - F3 and with added acerola extract containing 300 mg phenolics/kg - F4. The formulations were analyzed regarding the centesimal composition (moisture, protein, lipids, ash, and carbohydrates), pH, color (L*, a* and b*, C and h), water holding capacity, cooking weight loss, size reduction and oxidative stability (pH, color, and determination of thiobarbituric acid reactive substances - TBARS) during the frozen storage (-18 °C) for 60 days. The standard formulation (F1) complied with the current legislation of physical-chemical characterization for hamburger. The pH values ranged from 5.62 to 5.82. It was observed that in F4 the extract contributed to the maintenance of the color parameter a*. Formulations 2 and 4 containing BHT and added acerola extract (300 mg phenolic/kg), respectively, were the ones that best inhibited lipidic oxidation until 60 days of storage, presenting the lowest production of malonaldehyde. Thus, the addition of acerola extract was shown to be an effective alternative to the synthetic antioxidant BHT in preventing lipid oxidation of beef burgers.