Physicochemical and structural changes in myofibrillar proteins from porcine longissimus dorsi subjected to microwave combined with air convection thawing treatment

The effect of microwave combined with air convection thawing (MAT) on the properties and tertiary structure of myofibrillar proteins (MPs) from porcine longissimus dorsi muscle was investigated and compared with single treatments (air thawing, microwave thawing) and fresh meat (FM). Among the thawing treatments, the carbonyl content, dityrosine content, and surface hydrophobicity of MPs in MAT were the lowest, whereas the total sulfhydryl content, water-holding capacity, and Ca2+-ATPase activity were the highest, suggesting that MAT retained MPs properties better. MAT possessed a more stable tertiary structure and exhibited slight changes in MPs aggregation and degradation. There was an insignificant difference (P > 0.05) in the immobilized water and free water between the MAT samples and FM, indicating a tighter interaction between water and muscle protein in MAT. Thus, MAT could retain the physicochemical and structural properties of MPs, which provided a combination of thawing treatments for application in meat industry.

Automated summary

The study showed that microwave combined with air convection thawing (MAT) was more effective in retaining the properties and tertiary structure of myofibrillar proteins (MPs) from porcine longissimus dorsi muscle compared to other thawing methods, making the properties of MPs in MAT closer to fresh meat. Additionally, there was a tighter interaction between water and muscle protein in MAT compared to fresh meat.