Antifungal CoAl layered double hydroxide ultrathin nanosheets loaded with oregano essential oil for cereal preservation.

Fungal infestation of cereals seriously affects human health and the economy. Protecting cereals from fungal infestation is meaningful. Therefore, safe and economical antifungal agents must be explored. Oregano essential oil (OEO) has broad-spectrum antifungal activity but is unstable and poorly water-dispersible. CoAl-LDH ultrathin nanosheets (CoAl-LDH UNs) are a biosafe carrier with peroxidase-like activity and good water dispersibility. A new nanocomposite was constructed by integrating OEO and CoAl-LDH UNs named OEO/CoAl-LDH UNs. The antifungal activity of OEO was improved for the synergetic effect of OEO and CoAl-LDH UNs. OEO/CoAl-LDH UNs showed excellent antifungal activity against Fusarium moniliforme, Fusarium graminearum and Aspergillus flavus. A polyvinyl alcohol film containing OEO/CoAl-LDH UNs was prepared as a food package and effectively inhibited fungal infestation on cereals. This work can provide some insights for the exploration of other new antifungal materials. The good biosafety of this antifungal material can be effectively applied to food packaging.