Emballage alimentaire édile actifs enrichis en extraits naturels des plantes

Abstract

This study explores the antioxidant potential of chia seed mucilage and by-products from the hydrodistillation of essential oils of Thymus algeriensis and Thymus munbyanus, and their application in the development of bioactive edible films for fruit preservation. Aqueous and solid residues, often discarded during essential oil extraction, were recovered and incorporated into a chia mucilage-based film matrix. The antioxidant activity of both the thyme extracts and chia mucilage was assessed using DPPH scavenging, ferric reducing power (FRAP), and iron chelation assays. All extracts demonstrated concentration-dependent antioxidant effects, with aqueous residues extracts of Thymus munbyanus showing the highest activity and the highest amount of phenolic compounds (232.87 mg GAE/g extract) The prepared biofilms were characterized for their physical properties. Enriched films showed almost homogeneous appearance, increased opacity (reached 3.87 A/mm), and maintained good flexibility and elasticity. Moisture content and thickness were acceptable in the range of 32.57-42.22 for moister and 0.123-0.250 mm for thikness., indicating stable and practical film formation. Biofilms enriched with thyme extracts were then applied as coatings on bananas and compared to non-enriched films mucilage and untreated banana. Results showed that enriched films, particularly those containing 2% aqueous extracts of both thyme species, significantly delayed browning and degradation over a 10-day period, while non-enriched films and mucilage had limited effect. The effectiveness of the coatings was linked to the polyphenol content of the extracts and their ability to inhibit enzymatic browning. These findings highlight the potential of valorizing agro-industrial by-products in the creation of natural, antioxidant-rich biofilms, biodegradable films, offering a sustainable alternative to synthetic coatings for fresh fruit preservation.