Enhancing Retail Colour Stability and Shelf Life of Lamb Meat for Key Markets

Consumers choose to buy meat primarily by visual appearance. A meat cut red in colour is more likely to be sold than a cut brown in color forcing the retailers to discount the prices of discolored meat leading to economic losses. The appearance of brown on the meat surface is an oxidative process which reflects the antioxidant potential of muscles. Antioxidants have been reported to influence both lipid and protein oxidation and Vit E (α-tocopherol) and have been extensively documented to minimize lipid oxidation and improve meat colour stability (Ponnampalam et al., 2012; Suman et al., 2014a). However, there is not sufficient work published on the oxidative status of finisher lambs during hot summer days. Considering that growth is a trait that is affected by the intake of dietary antioxidants (Catoni et al., 2008) and that the high metabolic rate of growing tissues produces elevated levels of free radicals (Rollo, 2002), we hypothesize that antioxidant supplementation may help to counter the negative effects of oxidative stress (OS) associated with growth and short term heat stress (HS) which is often experienced by the finisher lambs in Australia. Therefore, the present project investigated the impact of dietary vitamin E (Vit E) and selenium (Se) supplementation during the finishing period on the oxidative status and meat colour stability of lambs exposed to short term hot conditions during the finishing period. The specific questions investigated were whether meat colour stability and shelf life can be enhanced by inclusion of high levels of antioxidants in finishing diets to reduce the negative impacts of heat stress on lambs. This project also compared the retail colour stability and shelf life of lambs finished on different levels of dietary antioxidants, under a grain based vs pasture system, under heat stress and thermoneutral conditions during finishing, transportation and in lairage.