LD. The centre of the steak used for chemical analysis was cut into 3
pieces, wrapped in aluminium foil, placed in a plastic bag and frozen
at −80 °C until analysis.
For colour stability measurements LD was cut into 2- to 4-cm
steaks posterior to those for chemical analysis steaks and aged in the
same way as steaks for shear force and sensory analyses. Two of the
steaks (V5M0 and V15M0) were cut on the right LD and the remaining
steaks (V0M0, V0M5 and V5M10) were taken on the left LD. We used
a procedure of sampling allowing for exposure of newly cut surfaces
of vacuum aged samples during storage in air, not the surfaces that
were exposed during vacuum storage. A 2-cm-thick steak was used
for samples that were stored in air (V0M0) or packaged in highoxygen
modified atmosphere (MA) for 5 days (V0M5) directly 3 days
postmortem. A 4-cm-thick steak was used for samples aged in vacuum
for 5 days, after which the meat was divided into two parts, one
directly stored in air (V5M0) and the other packaged in high-oxygen
MA (V5M10) for 10 days before storage in air. A 3-cm-thick steak was
used for samples aged in vacuum for 15 days (V15M0), of which 1 cm
was cut off before storage. After ageing, samples for colour stability
measurements were wrapped with oxygen-permeable plastic film
(NORM PACK 115 45-1; Teampac AB, 110 Tyresö, Sweden) and stored
in air at 4 °C for five days in darkness.