No abstract

This study was conducted to evaluate antilisterial activity in deli-style turkey using one of the inhibitors: hop α- or β-acids at 5 ppm, potassium acetate/potassium diacetate (PAPD) at 0.5%, their combinations, potassium lactate/sodium diacetate (PLSD) at 2.5% for positive control, and ethanol at 5 ppm for negative control. Deli-style turkey was formulated and manufactured traditionally. To simulate Listeria contamination in processing plants, the deli turkey was sliced in <24 h of production, inoculated with Listeria monocytogenes (2 to 3 log CFU/g), and vacuum-stored at 4 or 7°C for 60 d. To simulate Listeria contamination in grocery stores, the deli turkey was vacuum-stored for 30 and 60 d prior to slicing, inoculation, and aerobic storage at 4 or 7°C for 10 d. Physicochemical properties of the deli turkey were not significantly different among treatments (P > 0.05). Addition of hop acids at 5 ppm did not inhibit Listeria in deli meat during 60 d of vacuum-storage at 4 or 7°C, whereas organic acids and hop acids/PAPD significantly inhibited Listeria (P < 0.05), with the best inhibition observed for hop β-acids/PAPD at 7°C/60 d. During 10 d of aerobic storage at 4°C, hop acid/PAPD, PLSD, or PAPD showed listeristatic effects, whereas hop acids alone allowed Listeria to grow by 0.9 CFU/g. During 10 d of aerobic storage at 7°C, hop acid/PAPD, PLSD, and PAPD significantly reduced Listeria populations than hop α-acids, β-acids, and no-inhibitor control (P < 0.05). These results indicated the combination of hop β-acids/PAPD provides more effective inhibition than any single addition of hop acids and PLSD (P < 0.05) at 7°C/60 d in vacuum storage, with intermediate inhibition observed for PAPD and α-acids/PAPD.