Inhibition of Listeria monocytogenes on hot dogs using antimicrobial whey protein-based edible casings

Whey protein isolate (WPI) films (pH 5.2) containing p-aminobenzolc acid (PABA) were heat-sealed to form casings. Hot dogs prepared with WPI, collagen, or natural casings were cooked, surface-inoculated to contain 10(3) Usteria monocytogenes CFU/g, and examined for numbers of L. monocytogenes, mesophilic aerobic bacteria (MAB), lactic acid bacteria (LAB), and yeast/mold during 42 d of storage at 4 degreesC. Listeria populations on hot dogs prepared with WPI-1.0%-PABA casings remained relatively unchanged; however, numbers of Listeria on hot dogs prepared with WPI-0.0%-PABA, collagen, and natural casings increased about 2.5 logs during 42 d of refrigerated storage. Populations of MAB, LAB, and mold on WPI-1.0%-PABA casings were 1 to 3 logs lower compared to others casings.