Strategies to improve beef tenderness by activating calpain-2 earlier postmortem

Area of Science:

• Meat Science
• Food Chemistry
• Biochemistry

Background:

• Postmortem aging influences meat tenderness and quality.
• Calpain-2 is a key enzyme in meat tenderization.
• Understanding pre-rigor treatments can optimize meat processing.

Purpose of the Study:

• To investigate the effects of calcium chloride injection and freezing on sarcoplasmic calcium concentration and calpain-2 activity.
• To assess the impact of these treatments on beef tenderness, water holding capacity, and consumer acceptance.
• To analyze these effects in longissimus lumborum (LL) and semimembranosus (SM) muscles at different aging times.

Main Methods:

• Beef steaks (LL and SM) were treated with calcium chloride injection or freezing post-rigor.
• Sarcoplasmic calcium concentration and calpain-2 activity were measured at 1, 4, and 14 days post-treatment.
• Warner-Bratzler shear force, water holding capacity, and consumer acceptability were evaluated at 4 and 14 days post-treatment.

Main Results:

• Free calcium levels were significantly higher in calcium-injected steaks compared to frozen and control groups.
• Calpain-2 activity was reduced in both calcium-injected and frozen steaks for LL muscle.
• SM muscle showed the lowest calpain-2 activity in calcium-injected steaks and intermediate activity in frozen steaks.
• Calcium-injected LL steaks exhibited improved tenderness compared to control steaks.

Conclusions:

• Calcium chloride injection and freezing accelerate calpain-2 activation postmortem in beef.
• Calcium injection enhances the tenderness of longissimus lumborum steaks.
• These pre-rigor treatments offer potential strategies for improving beef quality attributes.