The retail color characteristics of vacuum-packaged beef m. longissimus lumborum following long-term superchilled storage

This study investigated whether beef m. longissimus lumborum (LL) can be merchandised under retail conditions, following long-term superchilled storage (-1 degrees C). At 24 h post-mortem, the LL from left side of beef carcasses (n = 5) were fabricated into vacuum packaged beef thick-cuts, and then stored for 0, 2, 4, 8, 12, 16, or 20 weeks under superchilled conditions (-1 degrees C). Following storage, beef cuts were fabricated into steaks and aerobically dis-played (0- 4 degrees C) for 5 days. Instrumental color, percentage of myoglobin redox forms, metmyoglobin reducing activity, oxygen consumption, and lipid oxidation were evaluated. After 4 weeks, the steaks had the highest a*, b* and chroma values between 1 and 3 days of display. Longer superchilled storage resulted in a rapid increase in discoloration and lipid oxidation which were observed in samples during display. Specifically, the a* values of steaks superchilled for 16 and 20 weeks approached the unacceptability threshold (a* >= 14.5) after 3 days of display.