Improvement of slow release property of starch/PVA active films containing carvacrol loaded by alkali-treated mycelium.

To serve as adsorption carriers, Mucorracemosus Fresenius (MF) mycelium and MF mycelium with alkali treatment (MFA) were prepared and subsequently loaded with carvacrol. The starch/polyvinyl alcohol (Starch/PVA) active films incorporated with carvacrol/MF and carvacrol/MFA complexes were developed by extrusion blow molding, and the properties of these films were investigated. Compared to MF mycelium, MFA showed better antioxidant activity, the adsorption capacity for carvacrol and hydrophilic property. The adsorption rate of MFA on carvacrol was approximately 1.8 times that of MF. The negative impacts of carvacrol on the film properties, such as diminished mechanical strength, reduced water vapor barrier capability, and increased microcracks in the cross-section, were reduced when carvacrol was loaded by MF or MFA. MFA was more effective than MF in delaying the release of carvacrol from the films into food simulant (10% ethanol) and protecting against carvacrol loss during the film preparation process. The addition of MF or MFA led to differing levels of antimicrobial and antioxidant activities of the films, suggesting a correlation with the release property of carvacrol. These findings showed that modifying mycelium through alkaline treatment may be a promising technical approach for developing slow-release active packaging films by utilizing mycelium as a carrier.