Effects of novel nitrite packaging film on the bacterial growth of bison strip-loin steaks
Narváez-Bravo, C., Rodas-González, A., Ding, C., López-Campos, O., Galbraith, J., Larsen, I.L., Ye, J., Siegel, D., Aalhus, J.L. (2017). Effects of novel nitrite packaging film on the bacterial growth of bison strip-loin steaks. Journal of Food Processing and Preservation, [online] 41(6), http://dx.doi.org/10.1111/jfpp.13311
Plain language summary
Bison meat is prone to early browning in oxygen-permeable retail display packaging. This study evaluated different packaging methods as a means to prevent early retail packaging and prevent bacterial growth. Bison strip loins were packaged with one of the following methods: overwrapped with polyvinyl chloride film = PVC, vacuum skin packaging = VSP, and vacuum skin packaged with a film coated in a small amount of nitrite=NIT). Colour measures and bacterial counts from swab samples were obtained prior to packaging and after 7 days under simulated retail conditions. VSP and NIT packaged striploins had better color stability and lower bacterial counts after ageing under retail conditions relative to traditional PVC oxygen permeable packaging.
This study aimed to determine the effect of different packaging types (overwrapped with polyvinyl chloride film = PVC, vacuum skin packaging = VSP, and vacuum skin packaged with nitrite film = NIT), swabbed steak surface (bottom and top) and ageing time (2 and 9 days) on color stability and spoilage bacteria counts of bison striploin steaks after 7 days of retail display. In comparison to PVC packaging, both VSP and NIT showed more stable color and reduced the bacterial load on the steaks by ∼2log10 for coliforms (p <.0001), ∼0.5 log10 for lactic acid bacteria (p =.005), and ∼1.5 log10 for psychrophilic bacteria (p =.0001). Ageing time (p <.05) increased all spoilage bacteria numbers (∼2 log). The NIT packaging system improved retail color stability of bison steaks; however, the decreased growth of bacteria during retail display was similar to other anaerobic packaging systems. Practical applications: Nitrite film packaging (FreshCase®), is a new smart packaging technology which contacts the meat surface, and nitrite embedded in the film surface dissolves into the meat juices, creating a stable, bright-red color in a vacuum package without curing the meat. The FreshCase® technology is already approved for use in the United States providing economic and market advantages to United States retailers. The packaging can offer more than 30 days of shelf life for whole muscle beef and extends typical retail display life up to 28 days compared to 3–5 days for tray over-wraps. This technology opens the possibility to the Bison industry to expand its market, where color stability is an issue and has the potential to eliminate retail losses due to poor color stability and early browning. This will allow the bison industry to transform from mainly frozen, to a more premium fresh meat market.