Abstract: This study reports on tissue exudate-based proteomic analysis of the effect of dietary supplementation of Allium mongolicum Regel powder (AMRP) and aging time on beef quality. A total of 12 healthy Angus calves aged (14 ± 2) months with similar body mass of (271.17 ± 17.6) kg were randomly divided into two groups. One served as control group and received a basal diet only, while the other group was fed a basal diet plus 20 g of AMRP every day. The experiment lasted for 135 days. At the end of the fattening period, all animals were slaughtered and samples of the longissimus thoracis muscle were taken for meat quality analysis. Tissue exudate was collected for proteomic analysis. The results showed that dietary addition of AMRP improved beef color and facilitated fat deposition. The fat and protein contents increased significantly with aging time. A total of 34 differential proteins were selected as potential biomarkers for beef quality indicators in the exudate, among which, myosin 1 (Q9BE40) and myosin-binding protein C1 (A6QP89) were highly significantly and positively correlated with the color parameter b*; isocitrate dehydrogenase (Q04467) showed a highly significantly positive correlation with water content; isocitrate dehydrogenase (Q04467) showed a highly significantly negative correlation with drip loss, fat, crude protein, and malonaldehyde (MDA) contents; and heat shock protein (HSP) 90 (Q76LV1) showed a highly significantly negative correlation with malonaldehyde (MDA) content. In conclusion, active components in A. mongolicum Regel can modulate differential protein expression and affect quality changes during beef aging through the glycolysis/gluconeogenesis and the cytoskeletal pathways in muscle cells.

Key words: tissue exudate; proteomics; aging time; beef quality; plant active ingredients