In vivo or in vitro application of vitamin E and the colour stability of low-oxygen packaged, sliced, pasteurised, differently cured pork shoulder model products

Abstract

The effect of dietary supplementation with vitamin E vs the in vitro addition of vitamin E on the colour stability of pasteurised comminuted pork shoulder model products was studied. Products were either manufactured with normal amounts of nitrite and ascorbate or with reduced levels of the additives. Half of the samples of sliced products from control meat (CON), from control meat supplemented in vitro with 5 and 50 mg kg -1 vitamin E and from meat derived from pigs receiving vitamin E supplements (SUP) were packaged under vacuum (VAC) and half in low-oxygen modified atmosphere packs (FOG). Duplicate packages were stored in the dark and under constant illumination for 21 days at 7°C.For the illuminated VAC-packaged products, significant temporary decreases in the redness values were observed for CON and the in vitro addition of 5 mg kg -1 vitamin E to CON. Both dietary supplementation with approximately 5 mg kg -1 extra vitamin E and the in vitro addition of 50 mg kg -1 vitamin E to CON were effective in preventing the temporary decrease in redness values. At the end of the experiment, the redness values of the VAC products approximated initially measured levels.The colour of the illuminated FOG-packaged products was stable throughout storage and the redness values of the SUP products were significantly better than those of the CON products. The in vitro addition of vitamin E had no effect on redness values here.The colour stability of VAC-packaged products containing the combination of reduced levels of nitrite and ascorbate was diminished in the initial period of illuminated storage. Similar effects were not observed for FOG-packaged products.