Abstract
The challenge of meat quality degradation due to transportation difficulties in high-altitude plateaus underscores the importance of an efficient thawing process for Tibetan pork to ensure its quality. This study compared four thawing methods ultrasound thawing (UT), refrigerator thawing (RT), hydrostatic thawing (HT), and microwave thawing (MT) to assess their impact on the quality of Tibetan pork, focusing on thawing loss, tenderness, color variation, and alterations in protein secondary structure and moisture content. Additionally, the study examined the impact of thawing on the metabolites of Tibetan pork using metabolomics techniques. The results indicated that UT yielded the highest quality samples. UT significantly accelerated the thawing rate and had minimal impact on tenderness compared to traditional thawing methods. Moreover, protein and lipid oxidation levels were reduced by UT treatment. Furthermore, it enhanced the binding capacity of protein and water molecules, reduced drip loss, and maintained meat color stability. What's more, amino acid metabolites such as l-glutamic acid, l-proline, oxidized glutathione, and 1-methylhistidine played a significant role in thawing oxidation in Tibetan pork, exhibiting a positive correlation with protein oxidation. UT resulted in a notable decrease in the levels of hypoxanthine and 2-aminomethylpyrimidine, contributing to the reduction of bitterness in the thawed meat and consequently enhancing the freshness of Tibetan pork. This study offers novel insights into understanding the biological changes occurring during the thawing process, while also furnishing a theoretical framework and technical assistance to improve the quality of Tibetan pork and propel advancements in food processing technology.