The pre- and post-grinding application of rosemary and its effects on lipid oxidation and color during storage of ground beef.

The timing of the application of rosemary extract was evaluated as one-way of minimizing myoglobin and lipid oxidation in ground beef. In experiment 1, rosemary extract was added to beef at four different stages namely trim, cube, coarse, and fine ground beef. The beef was evaluated for color and TBARS values during 144h of storage (4°C). Results showed that when rosemary was added to the pre-grinding treatments of trim and cube, ground beef had the highest a(∗) values (redness), oxymyoglobin content, and lowest TBARS values at 144h. In experiment 2, the effect of rosemary extract was evaluated on the color quality of case ready ground beef inoculated with 10(7)CFU/g Escherichia coli. Microbial counts, color, and TBARS values were measured during 144h of simulated storage. The results showed that both the rosemary treated samples that were inoculated and uninoculated remained redder longer and had lower TBARS values than the untreated inoculated and uninoculated controls. There was no significant inhibition of E. coli by the rosemary extract.