Efficacy of the FreshLightReg. 210 ultraviolet light system for control and elimination of Listeria innocua in a commercial poultry marinade-part A (flow rate = 10.6 GPM and turnover time = 2.4 minutes).

摘要

Possibility of the presence of Listeria in marinade solutions poses a threat to the safety of injected poultry products. Thus, a sample (25 gallons) of a fresh poultry marinade was collected from a USDA-inspected poultry processing facility and was shipped overnight to a laboratory under refrigerated conditions. Upon arrival at the laboratory, the marinade was inoculated with an overnight culture of Listeria innocua to a level of 3.4 logs/ml (cfu). The inoculated marinade was then passed through a FreshLightReg. 210 UV light system (Safe Foods Corporation, USA) for 10 min (flow rate = 10.6 gallons per min and turnover time = 2.4 min). Samples were collected after 0, 2, 4, 6, 8 and 10 min of UV light exposure, which corresponded to 0, 0.9, 1.7, 2.6, 3.4 and 4.3 calculated passes through the system. Samples of the marinade were plated on aerobic plate count PetrifilmTM3 to determine reductions in the inoculum over time. After 2 min of UV light exposure (approx. 1 pass through the UV light system), the level of L. innocua was reduced by 2 logs, at 8 min of exposure (3.4 passes) the level was reduced by 2.9 logs and at 10 min (4.3 passes) L. innocua could not be recovered from the poultry marinade solution. Thus, in 10 min of UV light exposure, levels of L. innocua in poultry marinade decreased from an initial level of 3.4 logs/ml to <1.0 log (the lower detection level) per ml, resulting in a >99.5% reduction in the original level of inoculum. It is suggested that the commercially available FreshLight 210 UV light system (FDA regulated under 21 CFR 179.39) may be an effective and low cost tool for controlling and eliminating L. innocua in commercial poultry marinades.