Label-free quantitative proteomics to reveal the potential mechanism of Lycium barbarum leaves extract-ε-polylysine‑sodium lactate complex coating on the stability of Tan mutton.

This study investigated a composite coating of ε-polylysine (ε-PL), sodium lactate (SL), and Lycium barbarum leaves extract (LBLE, total flavonoid content 260.50 mg/g) for preserving Tan mutton during superchilled storage. Overall, the coating significantly inhibited microbial growth, color deterioration, and protein oxidation, extending shelf life by 12 days (P < 0.05). Furthermore, the coating slowed down the changes in protein composition and the accumulation of TVB-N. Label-free proteomics identified 162 differentially abundant proteins (DAPs), including thioredoxin, myosin light chain, actin, and ribosomal proteins, which are closely related to amino acid synthesis, energy metabolism, muscle structure maintenance, and protein homeostasis. Through protein-protein interaction and correlation analysis, we identified 15 DAPs, including actin-binding protein (W5Q7L1), filamin A (W5P5A0), thioredoxin disulfide reductase (W5Q902), and phosphate transferase AK3 (A0A836AAD2), as potential biomarkers for maintaining the quality stability of Tan mutton during storage. These findings provide a theoretical basis for the development of new packaging strategies aimed at preserving the quality of Tan mutton.