Abstract: The effects of high pressure (up to 800MPa) applied at room temperature for 20 minutes on minced beef color and myoglobin were studied. The results showed that color values L* increased, a* values decreased and the meat becoming grey-brown with the increasing pressure. Simultaneously, the total extractible myoglobin decreased and the proportion of metmyoglobin increased signifi- cantly when the pressure reached above 400MPa. Packaging of meat under vacuum could not reduce the negative effect of pressure on beef color. However, curing with NaNO2 could stabilize the meat red color prior to high pressure treatment. Beef discoloration through pressure processing might result from oxidation of ferrous myoglobin to ferric metmyoglobin, globin denaturation and structural changes. The former could be prevented by curing and forming nitrosomyoglobin before pressure treatment.

Key words: high pressure treatment, minced beef, myoglobin, color