title: Antioxidant Effect of Extracts from the Coffee Residue in Raw and Cooked Meat.
abstract: The residue of ground coffee obtained after the brewing process (spent coffee) still contains various functional components with high antioxidant capacity and health benefits, but no attempts have been made to use it as a resource to produce value-added food ingredients. This study evaluates the antioxidant activity of ethanol or hot water extracts from the residues of coffee after brewing. An extraction experiment was carried out using the 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 compound (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2-thiobarbituric 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 systems, both the 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. These results indicated that the ethanol extracts of coffee residue have a strong antioxidant activity and have the potential to be used as a natural antioxidant in meat.
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50010, USA. jiheek@iastate.edu.
authors.forename: Ji-Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50010, USA. duahn@iastate.edu.
authors.forename: Dong Uk
authors.initials: DU
authors.lastname: Ahn
authors.affiliation: Department of Food Science and Technology, Chonnam National University, Gwangju 500-757, Korea. jbeun@jnu.ac.kr.
authors.forename: Jong Bang
authors.initials: JB
authors.lastname: Eun
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50010, USA. smoon@iastate.edu.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Moon
keywords: antioxidant; extract of coffee residue (ECR); meat system