Shelf life of ground beef enriched with omega-3 and/or conjugated linoleic acid and use of grape seed extract to inhibit lipid oxidation

The shelf life and oxidative stability of refrigerated raw ground beef enriched with omega-3 and/or conjugated linoleic acid (CLA) were studied. Grape seed extract (GSE) was used to inhibit lipid oxidation in the ground beef. Eight treatments of ground beef were established according to the enrichment of beef (control, enriched with omega-3, with CLA, or with omega-3 plus CLA) and the use of GSE (0 and 250mg GSE/kg product). Fresh beef was ground and mixed with GSE and salt. Treatments of beef were stored at 2 +/- 1 degrees C in aerobic packaging for 0, 1, 3, and 6days under retail display conditions. Oxidation stability (thiobarbituric acid-reactive substances [TBARS]), pH, instrumental color, metmyoglobin formation, and sensory attributes (color and odor) were measured. Omega-3-enriched beef increased the oxidation level at day 6 as determined by TBARS (P<0.05), but the instrumental color was not affected. The enrichment of CLA improved the coordinates of color (P<0.05) until day 3 and decreased the oxidation at day 6 (P<0.05). There were no differences in color and odor values among the types of beef during display, except at day 3, when CLA treatments had the highest scores. Addition of GSE decreasedthe oxidation level (P<0.001) and did not affect the instrumental color or the sensory parameters.