Myofibrillar protein gel properties are influenced by oxygen concentration in modified atmosphere packaged minced beef

•Minced beef was packaged in modified atmosphere with different oxygen concentrations.•Packaging with oxygen induced strong and elastic myofibrillar proteins gels.•Gels from meat stored without oxygen exhibited lower G′ and G″ values.•Water loss of gels prepared from meat packaged with oxygen was higher.•A mechanistic model involving protein cross-links is proposed.

Minced beef was stored for 8 days and myofibrillar protein (MP) was extracted to investigate the effect of oxygen concentration (0, 20, 40, 60, and 80%) in modified atmosphere packaging (MAP) on heat-induced gel properties. Compression force of gels was lower when prepared from beef packaged in 0% oxygen, intermediate in 20 to 60% oxygen and greater in 80% oxygen. Total water loss of gels prepared from beef packaged with oxygen (20-80%) was higher and rheology measurements presented higher G′ and G″ values. Additionally, gels from beef packaged without oxygen exhibited higher J (t) values during creep and recovery tests, demonstrating that oxygen exposure of meat during storage in MAP affect MP in such a way that heat-induced protein gels alter their characteristics. Generally, storage with oxygen in MAP resulted in stronger and more elastic MP gels, which was observed already at a relative low oxygen concentration of 20%.