Colour of beef heated to different temperatures as related to meat ageing.

The effects of ageing (10-12 days at +5°C), thermal treatment (internal temperature, T(i): 45, 60, 75°C) and oxygenation on the colour and some colour related physical and biochemical parameters of beef longissimus dorsi (LD) muscle were studied. The colour components (L(∗), a(∗) and b(∗) values) for the raw and heated LD, both before and after ageing and oxygenation, were instrumentally and sensorily evaluated. Ageing influenced colour components (except b(∗) value), specific activity of cytochrome c oxidase (SACCO) and amount of oxygen consumed (AOC). An increase in internal temperature was usually accompanied by a lower SACCO, AOC and total native muscle pigment concentration, as well as a change in all colour parameters. Oxygenation of the raw and heated slices (except T(i)=75°C) led to a less of black colour and a higher of red colour, a(∗) and b(∗) values.