Ginger extract inhibits lipid oxidation in ground beef.

Ground beef is a popular grocery commodity in the United States, constituting more than one-third of total beef sales and generating $12 billion in revenue annually.

The process of grinding accelerates the oxidation of muscle lipids. Lipid oxidation is a major reason for the deterioration of color and flavor in ground beef. It's possible to minimize any lipid oxidation-induced deterioration of quality in meat by incorporating synthetic and natural antioxidants into the product. But some studies have raised concerns about the health risks of synthetic antioxidants. So, the use of natural antioxidants has become highly relevant with regard to muscle foods.

Although ginger is an excellent source of natural antioxidants, the antioxidant potential of ginger extract in ground beef has not been explored thoroughly. Scientists at the University of Kentucky examined the usefulness of aqueous ginger extract for inhibiting lipid oxidation and discoloration in ground beef patties. Their work indicates that the extract can be used as a natural antioxidant that would minimize deterioration caused by lipid oxidation.

The researchers mixed fine ground beef containing 25% fat with 0.25% of aqueous ginger extract. Then they hand-formed these samples into 100-g patties. Control patties contained an equivalent volume of deionized water that was used to deliver the extract. The patties were overwrapped with polyvinyl chloride film, and stored at 2 C for 0, 48 and 96 hours under illuminated retail display conditions.

At the conclusion of the storage period, the investigators determined the amount of thiobarbituric acid-reactive substance in the samples as an indicator of lipid oxidation. Using a commercial colorimeter, the ratio of reflectance at 630 nm and 580 nm was calculated as an indirect estimation of surface discoloration.

Lipid oxidation was lower in the patties that contained the ginger extract than in the control patties, indicating that aqueous ginger extract can curtail lipid oxidation in ground beef. However, neither group of patties demonstrated any difference in reflectance ratio, which suggested that the ginger did not influence discoloration. The scientists are continuing to explore different antioxidant strategies for muscle foods.

Further information. Surendranath P. Suman, Department of Animal and Food Sciences, University of Kentucky, 405 W.P. Garrigus Building, Lexington, KY 40546; phone: [phone]; fax: [phone]; email: [e-mail].