Characterization and Antimicrobial Enhancement of Pea Protein–Agar Edible Films Incorporating Essential Oils for Food Packaging

Abstract

Growing concerns over plastic pollution have driven interest in edible films as sustainable packaging alternatives. Pea protein and agar are promising materials due to their biocompatibility and biodegradability. This study developed pea protein–agar edible films incorporating essential oils (eucalyptus, thyme, lemon, and niaouli) at 1–5% to enhance antimicrobial properties. Films with 2% thyme or niaouli oils showed activity against E. coli and S. aureus, while 3% thyme also inhibited fungi, A. niger. The strongest effect was observed with 3% thyme oil, showing inhibition zones of up to 2.7 cm. Yeast and mold counts decreased over 1000-fold, and bacterial counts decreased 15-fold. Films with 5% thyme oil had the lowest swelling, and color varied with oil type and concentration. When applied to strawberries, thyme oil films reduced microbial growth and maintained color and pH, effectively extending the shelf life. Overall, thyme oil-enriched pea protein–agar films offer a promising strategy for food preservation.