Active biocomposite packaging films based on carboxymethyl cellulose/sodium alginate/polyethylene glycol reinforced with spent ground coffee melanoidins for oily food applications.

A biodegradable active packaging film was developed from carboxymethyl cellulose/sodium alginate/polyethylene glycol (CMC/SA/PEG) incorporating spent-ground-coffee melanoidinss (SGCM) with different concentrations (from C1 to C3) to protect coffee peanut butter during refrigerated storage (4 °C, 40 days). Melanoidins incorporation markedly enhanced the antioxidant functionality of the films in a concentration-dependent manner. The films containing melanoidins exhibited DPPH and ABTS radical-scavenging activities of 24.83% and 18.72% for C1, 64.25% and 70.63% for C2, and 74.80% and 82.67% for C3, respectively. While improving surface water resistance (WCA 44.82° to 82.61°) and reducing WVP from ≈2.8 × 10-10 to ≈1.05 × 10-10 g·m-1·s-1·Pa-1 at C2. The films showed dose-dependent antibacterial activity (up to ≈16.54 mm inhibition zone). In peanut butter, oxidation was strongly delayed: PV at day 40 ranked C2 ≈ 4.2 < C3 ≈ 6.3 < C1 ≈ 7.2 < PE ≈ 9.5 < control ≈11.1 meq O₂/kg, and Thiobarbituric acid reactive substances (TBARS) reached ≈4.0 (PE) vs ≈ 3.2 (control) but remained ≤ ∼ 1 mg MDA/kg with C2.