Antioxidant Effect of Extracts from the Coffee Residue in Raw and Cooked Meat

Abstract

<p>This study evaluated the antioxidant activity of ethanol or hot water extracts from the residues of coffee after brewing. The extraction experiment was carried out using conventional solid–liquid methods, including ethanol and water as the extraction media at different temperatures and liquid/solid ratios. The antioxidant activity of extracts was tested for total phenolic compounds (TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH), and 2-thiobariburic acid reactive substances (TBARS) using oil emulsion and raw/cooked meat systems. The DPPH radical scavenging activity of the ethanol extracts with heating (HEE) and without heating (CEE) were higher than that of the hot water extracts (WE). The highest DPPH value of HEE and CEE at 1000 ppm was 91.22% and 90.21%, respectively. In oil emulsion and raw/cooked meat systems, both of water and ethanol extracts had similar antioxidant effects to the positive control (BHA), but HEE and CEE extracts showed stronger antioxidant activities than WE extract. The ethanol extracts of coffee residue had a strong antioxidant activity, and thus have potential to be used as a natural antioxidant in meat.</p>