Abstract: The concentrations, SDS-PAGE profiles, particle sizes and surface hydrophobicities of water soluble and salt soluble proteins, protein degradation index, and volatile flavor compounds in samples collected at different stages of sauced beef processing (raw meat, tumbling, cooking, and sterilization at 90, 105, 110 or 120 ℃) were analyzed using a Kjeldahl nitrogen analyzer, a nanoparticle potential analyzer, and headspace-solid phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results illustrated that as the process proceeded and sterilization temperature rose, protein concentration decreased, and protein degradation index increased significantly (P < 0.05). The change of protein particle size showed a consistent trend with surface hydrophobicity, and the maximum values were found in the tumbled sample, which decreased significantly after heating (P < 0.05). A total of 42, 50, 79, 70, 75, 79 and 74 volatile flavor compounds were respectively detected in the above seven samples, and the highest total amount of volatile compounds was determined in the unsterilized finished product, which declined after sterilization. The total amount of volatile flavor compounds in the sample sterilized at 105 ℃ was significantly higher than that in other sterilized samples (P < 0.05). In conclusion, sauced beef processing and sterilization could promote the degradation of proteins and the formation of volatile flavor compounds, but too high temperature could affect the denaturation and oxidation of proteins, and the flavor of the sample undergoing sterilization at 105 ℃ was the closest to that of the unsterilized sample. The findings of this study will provide a theoretical basis for the industrial production and flavor control of traditional sauced beef products.

Key words: sauced beef; processing; sterilization temperature; protein degradation; volatile flavor compounds