Evaluation of antibacterial activity of whey protein isolate coating incorporated with nisin, grape seed extract, malic acid, and EDTA on a Turkey frankfurter system.

The effectiveness of whey protein isolate (WPI) coatings incorporated with grape seed extract (GSE), nisin (N), malic acid (MA), and ethylenediamine tetraacetic acid (EDTA) and their combinations to inhibit the growth of Listeria monocytogenes, E. coli O157:H7, and Salmonella typhimurium were evaluated in a turkey frankfurter system through surface inoculation (approximately 10(6) CFU/g) of pathogens. The inoculated frankfurters were dipped into WPI film forming solutions both with and without the addition of antimicrobial agents (GSE, MA, or N and EDTA, or combinations). Samples were stored at 4 degrees C for 28 d. The L. monocytogenes population (5.5 log/g) decreased to 2.3 log/g after 28 d at 4 degrees C in the samples containing nisin (6000 IU/g) combined with GSE (0.5%) and MA (1.0%). The S. typhimurium population (6.0 log/g) was decreased to approximately 1 log cycles after 28 d at 4 degrees C in the samples coated with WPI containing a combination of N, MA, GSE, and EDTA. The E. coli O157:H7 population (6.15 log/g) was decreased by 4.6 log cycles after 28 d in samples containing WPI coating incorporated with N, MA, and EDTA. These findings demonstrated that the use of an edible film coating containing nisin, organic acids, and natural extracts is a promising means of controlling the growth and recontamination of L. monocytogenes, S. typhimurium, and E. coli O157:H7 in ready-to-eat poultry products.