Dietary vitamin E supplementation reduces lamb meat browning on display following up to 70 days of chilled storage

•High muscle vitamin E improves retail lamb colour regardless of chilled storage.•High muscle vitamin E reduced browning more in lamb stored for 35d than 5 or 70 d.•High marbling, pH or oxidative capacity did not worsen browning after 70 d storage.•High vitamin E reduced browning more in highly marbled lamb loin stored for 5d.•Dietary vitamin E reduces retail browning of lamb meat stored for up to 70 d. Rapid browning limits the retail display of lamb meat, particularly following extended chilled storage that is typical of international shipment. Lamb stored chilled for short periods browns more rapidly on retail display when the meat has high levels of marbling (intramuscular fat), a high pH or greater oxidative capacity. In contrast, high muscle vitamin E concentration reduces browning of short stored lamb meat on retail display. However, the capacity of dietary vitamin E supplementation to reduce retail browning in lamb meat following extended chilled storage is unknown. Additionally, the ability of vitamin E to mitigate the negative impacts of intramuscular fat, pH and oxidative capacity on meat browning following chilled storage is unknown. Sixty six industry sires of Terminal, Merino and Maternal breed types were bred with Merino and Merino-cross dams to produce 132 lambs. The two lambs from each sire were divided into two vitamin E treatment groups that were housed in 12 pens (6 pens per treatment) for 8 weeks leading up to slaughter. Control lambs (6 pens of 11 lambs) were fed a pelleted ration containing basal levels of vitamin E (30 mg/kg feed) while supplemented lambs (6 pens of 11 lambs) were fed the same ration with increased vitamin E content (275 mg/kg feed). After slaughter, the m. longissimus lumborum was sampled for measurement of vitamin E concentration, intramuscular fat, pH, oxidative enzyme isocitrate dehydrogenase activity, and retail meat colour. Colour samples were vacuum packaged for storage at −1 °C for 5, 35 and 70 d, before being re-sliced, wrapped and placed under stimulated retail display where meat redness (R630/R580) was measured 24 hourly for 72 h. Lamb pens supplemented with vitamin E produced redder loin meat at 24, 48 and 72 h of display compared to control pens of lambs (P