The effect of ageing on chosen quality characteristics of skeletal muscles of Aberdeen Angus bulls.

The objective of the trial was to study the qualitative parameters of two muscles of Aberdeen Angus bulls with 250-300 kg carcass weight. After slaughter, longissimus thoracis et lumborum (LD) muscle and unseparated semimembranosus and adductor femoris (SMA) muscles were removed from the chilled carcasses. Muscles were vacuum-packed and wet aged at +2 °C for 10, 14, 18 and 20 days. Meat pH, electrical conductivity, shear force and colour were measured in all ageing times. Two thermal treatment methods (sous-vide (SV) and grilling) were used to determine cooking losses. The effects of muscles, ageing times and muscles by ageing times interaction was found with two-factorial analysis of variance. The effects of muscles, ageing times and muscle groups by ageing time interaction for raw and SV treated meat shear force was significant. Ageing decreased SV treated meat shear force from day 10 (40.8 N) to 18 (29.7 N). Fresh and SV treated LD muscle was tougher compared to the SMA muscle group, but SM showed a better response to the tenderness within 20 days of ageing. Redness and yellowness value was higher in the SM group in comparison to LD. Muscles showed good colour (lightness, redness and yellowness) stability within ageing for 20 days. No interactions were found between muscle groups and ageing times for SV treated and grilled beef cooking losses. However, SV treated meat lost more weight than grilled meat slices. The present study suggests that the optimal ageing time for meat is 18 days when the grilled meat cooking loss is the lowest. [ABSTRACT FROM AUTHOR]