Atividade antioxidante de extrato de soja preta na estabilidade oxidativa e cor de hambúrguer de carne bovina

Abstract

The objective of this work was to obtain a hydroalcoholic extract of black soybeans and verify the technological application of this natural antioxidant in frozen bovine hamburger. It was elaborated hamburgers containing 0,5%, 1%, 1,5% of black soybean antioxidant extract, and hamburgers without antioxidant addition (negative control) and using the artificial antioxidant, BHT (positive control). Analyzes of pH, color, thiobarbituric acid reactive substances (TBARS) and the peroxide index in hamburgers were performed at 30 day intervals for 120 days of frozen storage. The hydroalcoholic extract obtained from black soybean presented values of 2853,10 mg GAE/L, 304,48 mg ci-3-gli/L and 16071,56 μmol TE/L for total polyphenols, total anthocyanins and antioxidant capacity, respectively. Regarding color, there was no significant difference between the treatments and the storage days for the L* and oh parameters. The pH of the burgers has increased over the storage period. Mean values of TBARS increased throughout storage in the different treatments, with a significant difference at 60 and 90 days of storage. The peroxide index increased from 90 days of storage in all treatments. It is concluded that the concentration of natural antioxidants used is not sufficient to maintain the oxidative stability of the product during the 120 days of storage at -18 °C.