Formulation, characterization, and application of grape seed extract and chitosan nanoemulsion for coating of beef preservation

• LC-MS confirmed polyphenolic compounds in the examined grape seed extract. • Zeta potential and PDI results indicated the stability of nanoemulsion. • Nanoemulsion enhanced the microbiological, chemical, and sensory properties of beef. This study aimed to develop a chitosan-based nanoemulsion incorporating grape seed extract (GSE) and to evaluate its effectiveness in preserving beef during refrigerated storage at (4 ± 1°C) for 16 days. LC–MS analysis identified 14 polyphenolic compounds in the GSE, with catechin and epicatechin as the predominant constituents. The optimized nanoemulsion, formulated using Tween 80, demonstrated excellent colloidal stability, maintaining a small particle size (∼16 nm) and a high positive zeta potential (∼45 mV) over a storage period of 21 days. Application of the nanoemulsion as an edible coating significantly (P < 0.05) inhibited microbial growth in beef samples, resulting in lower counts of mesophilic, psychrotrophic, lactic acid bacteria, and Pseudomonas spp. compared with uncoated controls. Among the tested formulations, coatings containing 1% GSE were the most effective, as evidenced by delayed increases in pH, total volatile nitrogen (TVN), and thiobarbituric acid reactive substances (TBARS) throughout refrigerated storage. Sensory evaluation further confirmed that beef samples coated with the 1% GSE nanoemulsion maintained superior color, odor, texture, and overall acceptability up to day 16. Overall, the chitosan–GSE nanoemulsion coating effectively extended the shelf life of beef through combined antimicrobial and antioxidant activities, highlighting its potential as a natural preservation strategy for meat products.