Ageing and tenderness of beef

Twenty loins were taken to examine the influence of the duration of ageing on different beef quality traits, mainly on tenderness. The study was based on Fleckvieh bulls with an age between 16 and 18 months. Origin, fattening system, slaughtering and treatment of the carcasses have been identical. Ten 2.5 cm thick steaks were cut from each loin 48 hours post mortem. The steaks were stored 1, 2, 3, 5, 7, 10, 14, 21, 28 or 36 days at 2 degrees C in a vacuum package. Thus 20 samples were examined on each ageing time. Ageing had a marked effect on the Warner-Bratzler shear force values. The effect was more distinct within the first 10 days than in the time afterwards. The shear force values were more than 50 % lower after 35 days of ageing than the initial values (77 N day 2-->38 N day 36). Although the variation of the shear force within the daily probes decreased in the course of ageing, it remained still relatively high. Therefore, it can be concluded, that long ageing reduces the risk of getting tough meat significantly, but does not prevent it completely. Ageing longer than 10 to 14 days - the recommended time in practice - certainly improves tenderness and reduces the variation. The metmyoglobin content on the surface of the M. long. dorsi was getting higher over the ageing (19.5 % day 1 --> 20.9 % day 28 and 29) but remained on a level, that was irrelevant for the practice.