Application of pressures of 80-100 MPa for 20 min improved the colour stability, as measured by rate of metmyoglobin formation, of longissimus dorsi and psoas major beef muscles exposed to air 2 clays post-slaughter. However, pressure treatment of these muscles at 7-20 days post-slaughter did not improve their colour stability. It is suggested that pressure inhibits, at least partially, the mechanism(s) responsible for the low colour stability of very fresh beef. (C) 1997 Elsevier Science Ltd.