Abstract: In an effort to investigate the effect of addition of different levels (0%, 0.2%, 0.5% and 1.0%) of vacuum freeze-dried (VFD) garlic powder to myofibrillar protein (MP) extracted from yak meat on its emulsification properties in the Fenton oxidation system, MP was evaluated for active sulfhydryl content, protein solubility, and surface hydrophobicity, percentage of interface adsorbed protein, emulsion viscosity, emulsification activity, emulsion stability (clarification index, integrated light transmittance, sedimentation rate) and microstructure after oxidation for 12 h at 4 ℃ in the oxidation system. The results showed that addition of high levels of VFD garlic powder (0.5% and 1.0%) significantly enhanced the emulsification activity, emulsion stability and oil phase distribution uniformity of MP in the Fenton oxidation system (P < 0.05). Adding 0.5% of VFD garlic powder provided good protection for yak meat MP in the Fenton system, resulting in a 2.55-fold increase in active sulfhydryl content, a 19% increased in protein solubility and a 25.41% reduction in surface hydrophobicity. Adding 1.0% of VFD garlic powder significantly improved the emulsification characteristics of yak meat MP in the Fenton oxidation system, increasing the viscosity of yak meat MP emulsion by 2.02 times, and the emulsification activity by 49.80%, and reducing the clarification index, integrated light transmittance and sedimentation speed by 17.06%, 37.44% and 50.79%, respectively. These results suggested that VFD garlic powder significantly improves the emulsification characteristics of yak meat MP in the Fenton oxidation system, and its effect depends on the addition amount of VFD garlic powder. Addition of 1.0% of VFD garlic powder is more effective.

Key words: yak meat; myofibrillar protein; vacuum freeze-dried garlic powder; emulsifying properties