Effect of ultrasound‐assisted L‐lysine treatment on pork meat quality and myofibrillar protein properties during postmortem aging

• Published in: Journal of food science 2024-07, Vol.89 (7), p.4162-4177
• Main Authors: Xu, Shuangyi, Guo, Xiuyun, Fu, Chao, Wang, Jipan, Meng, Xiangren, Hui, Teng, Peng, Zengqi
• Format: Article
• Language: English
• Subjects: Aging; Amino acids; Buried structures; Hydrophobicity; Lysine; L‐lysine; Meat; Meat quality; Pork; postmortem aging; Protein folding; protein properties; Protein structure; Proteins; Shear forces; Solubility; Sulfhydryl groups; Ultrasonic imaging; Ultrasonic processing; Ultrasound
• ISSN: 0022-1147; 1750-3841; 1750-3841
• DOI: 10.1111/1750-3841.17131

This paper aimed to investigate the effects of ultrasound‐assisted L‐lysine treatment on meat quality and myofibrillar proteins (MPs) properties of pork longissimus dorsi during postmortem aging. The results revealed that the L‐lysine (Lys) and/or ultrasound treatment significantly increased (p < 0.05) the water‐holding capacity and tenderness of the pork during postmortem aging, while the ultrasound‐assisted Lys treatment had the lowest cooking loss, pressurization loss, Warner–Bratzler shear force, and hardness. In addition, L‐lysine and/or ultrasound treatment increased (p < 0.05) pH value, T21, and myofibrillar fragmentation index, while the ultrasound‐assisted Lys treatment had the highest value. Meanwhile, the protein solubility was increased with Lys and/or ultrasound treatment during postmortem aging, and ultrasound‐assisted Lys treatment had the highest solubility, reaching 88.19%, 92.98%, and 91.73% at 0, 1, and 3 days, respectively. The result of protein conformational characteristics showed that Lys and/or ultrasound treatment caused the unfolding of the α‐helix structure, resulting in the exposure of more hydrophobic amino acids and buried sulfhydryl groups, ultimately enhancing MPs solubility. In summary, ultrasound‐assisted Lys treatment altered the structure of MPs, resulting in the enhancement of the water‐holding capacity and tenderness of the pork. Practical Application This study showed that ultrasound‐assisted L‐lysine (Lys) treatment could enhance the water‐holding capacity and tenderness of pork during postmortem aging. The results might provide a reference for the application of ultrasound‐assisted Lys treatment on the improvement of pork meat quality. To facilitate practical applications in production, the development of medium and large‐sized ultrasound equipment for conducting small‐scale and pilot experiments is crucial for future research.