Antioxidant and antimicrobial activity of rosemary extract in chicken frankfurters

The antioxidant and antimicrobial effects of commercially available oil-soluble rosemary extracts VivOX 20 and VivOX 4 were investigated against lipid oxidation and microbial growth in vacuum-packed chicken frankfurters. The contents of the main active ingredient, carnosic acid, in extracts was 20% and 4% (w/w), respectively. For comparison, the activity of commercially available preservative Robin LI LS was also tested. The control was chicken frankfurters made without test additives. Antioxidant tests were performed at 3 storage tempertures (4, 12, 25 degrees C), using the Rancimat method. Antimicrobial effect was investigated by aerobic plate count. Results showed that both rosemary preparations possess antioxidant and antimicrobial properties that may make them useful in the food industry. In chicken frankfurters with added VivOX 20 and VivOX 4, higher oxidative stability was exhibited at all storage temperatures, as in frankfurters with Robin LI LS. Addition of VivOX 20, VivOX 4, and Robin LI LS also significantly reduced the aerobic plate count, compared to controls, stored at 4 or 12 degrees C.