Avaliação da atividade antioxidante de extrato de inflorescência de bananeira (Musa cavendishii) e sua aplicação em hambúrguer de carne suína

Abstract

This study aimed to evaluate the functionality of extracts from banana inflorescence (Musa cavendishii) obtained under different extraction conditions, and to analyze the effect in pork burgers. The extracts were obtained by conventional stirring and ultrasound, varying the ethanol concentration (50, 70 and 90%), time (30, 45 and 60 minutes) and temperature (20, 40 and 60 °C). The levels of phenolic compounds, total flavonoids and antioxidant activity were quantified by the DPPH and FRAP methods. The best results were found for extraction using stirring and without the use of ultrasound at 60 ºC for 30 minutes with an ethanol concentration of 50%, which resulted 1690.0 mg EAG/100g of total phenolic compounds and IC50 of 0.31 μg/mL; this extract was then applied in the products. The pork burgers were prepared with different concentrations of the extract of banana inflorescence (0, 1.0 and 2.0%) and sodium erythorbate (0.100, 0.150 and 0.200%), synthetic antioxidant commonly employed in meat products, and stored for 120 days at -12 º C. Microbiological and chemical composition analyses were performed, and every 30 days pH, color and TBARS values (substances reactive to 2-thiobarbituric acid), were evaluated. Also sensory evaluation was performed on days 10 and 60. There was no significant difference (p > 0.05) in the chemical composition of the different burgers developed. All the treatments showed a reduction in pH during storage, which was not affected by the addition of the extract. During storage, all the treatments showed a decrease in the intensity of red coloring, and the burgers without the addition of extract were yellower in color. TBARS values increased linearly during storage; at 120 days all the treatments with added extract of banana inflorescence had significantly (p< 0,005) lower TBARS values than the other treatments. The treatment with 0.200 % of added sodium erythorbate and 2.0% extract was most effective in delaying lipid oxidation. The sensory evaluation showed that the treatments maintained their sensory characteristics, with good tasters acceptability. The banana inflorescence was shown to be a potential source of antioxidant compounds and its extract showed satisfactory results to ensure the shelf life of pork burgers in relation to lipid oxidation, without causing damage to the physicochemical and sensory characteristics of the product.