The Use of Carbon Monoxide as a pre-packaging treatment in Beef

摘要

Consumers choose beef primarily based on colour and associate a bright red colour with freshness and wholesomeness. Packaging must preserve and present the meat in a pleasing manner. Vacuum packaging serves to preserve the product well but causes the meat to become much darker than consumers prefer. Alternative packaging systems such as Modified Atmosphere Packaging (MAP) which include oxygen cause the meat to exhibit a bright cherry-red colour but are not as effective in product preservation and may give rise to other problems such as lipid oxidation and loss of meat tenderness. Carbon monoxide (CO) as a MAP gas also induces the cherry-red colour. The colour is more long-lasting than that induced by oxygen. For the purposes of this research CO was not used as a packaging gas but as a pre-treatment before packaging. A gas mixture of CO, Carbon dioxide and Nitrogen was used at 5, 60 and 35% respectively. The gas was then removed and the samples were vacuum packed. LD muscles were pre-treated at 4°C for a range of times varying from 30 minutes to 72 hours and then assayed over a 21 day period for colour, pH, tenderness, cooking-loss, lipid oxidation and microbial counts. Some consumers are concerned that the prolonged red colour could be used to market meat beyond its sell-by-date. The shorter exposure times in this pre-treatment regime cause the beef colour to return to the normal vacuum induced dark colour before the product reaches its use-by-date thus allaying consumer concerns.