Nitrite embedded vacuum packaging improves retail color and oxidative stability of bison steaks and patties

Citation

J. C. Roberts, A. Rodas-González, J. Galbraith, M. E. R. Dugan, I. L. Larsen, J. L. Aalhus and Ó. López-Campos. 2017. Nitrite Embedded Vacuum Packaging Improves Retail Color and Oxidative Stability of Bison Steaks and Patties. Meat and Muscle Biology. 1:169-180. doi:10.22175/mmb2017.03.0015

Plain language summary

Bison meat will rapidly discolour under retail packaging conditions. This can be costly to retailers as consumers tend to use meat colour as an indicator of freshness. The aim of this study was to determine if the color stability of bison steaks and burger patties could be improved through packaging meat with a vacuum-sealed film containing embedded sodium nitrite. The small amount of sodium nitrite in the film dissolves and binds to the pigments in the meat producing a bright red surface colour. To test the effectiveness of this packaging technology with bison meat, steaks and burger patties were packaged in either vacuum-sealed film with embedded sodium nitrite or packaged in oxygen permeable packaging. Packaged bison steaks and burger patties were then aged under simulated retail conditions. Over a 4 day period, the bison meat packaged in oxygen permeable packaging became darker and more discoloured. The bison meat packaged in the nitrite embedded vacuum sealed film did not discolour and became brighter and redder over the retail display. Previous studies have also shown due to the vacuum sealing, there is less bacterial growth in this packaging system than with oxygen permeable packaging. This study shows nitrite embedded vacuum sealed packaging is an effective means to reduce discolouration in bison meat.

Abstract

Bison meat is prone to rapid discoloration under traditional aerobic retail packaging conditions. The aim of this study was to determine if the color stability of bison steaks and burger patties could be improved through packaging meat with a vacuum-sealed film containing embedded sodium nitrite. Bison bulls (n = 40) were slaughtered and the longissimus lumborum (LL) and rhomboideus (RH) were removed. Following a postmortem aging period of 6, 13, or 20 d steaks were obtained from the LL. RH muscles aged 6 d were ground (85:15 lean to fat) and formed into 140 g patties. One steak and two burger patties from each carcass side were placed into either a polystyrene tray overwrapped with oxygen permeable polyvinyl chloride film (CONT) or a polyethylene tray vacuum sealed with film coated in sodium nitrite (113 mg × m–2; NIT); meat was placed under simulated retail conditions for 4 d. A 3-way interaction was observed between packaging type, whole muscle aging and time in retail display for objective (L*, Chroma, and Hue) and subjective (lean color score and proportion of surface discoloration) color measures from steaks (P < 0.0001). The CONT packaged meat showed an increased area of discoloration and in metmyoglobin after 4 d in retail display (P < 0.0001); NIT meats did not show a higher area of discoloration or metmyoglobin after retail display. Additionally, NIT packaged steaks and burger patties lightened (higher L*) and became redder over the course of the retail display period. Thiobarbituric acid reactive substances (products of lipid peroxidation) did not increase in NIT packaged burger patties after 4 d under retail conditions, however, there was a significant increase observed for CONT packaged burger patties (P < 0.0001). NIT packaging appears to effectively improve the color stability of bison meat under retail conditions, making this packaging strategy well suited to address the issue of rapid discoloration.