Application of chitosan/Nano-TiO₂/Daisy essential oil composite film for the preservation of Actinidia arguta: Inhibition of spoilage microorganisms and induction of resistance.

Abstract

This study explores the inhibitory effects of a chitosan/nano-TiO₂/Daisy Essential Oil (CSTD) composite film on spoilage microorganisms affecting Actinidia arguta. Owing to its high nutritional value and water content, Actinidia arguta is highly susceptible to microbial spoilage, leading to a significantly shortened shelf life. Traditional chemical preservation methods are ineffective against microbial spoilage and raise concerns about safety and environmental sustainability, highlighting the demand for natural, effective alternatives. Chitosan, a natural polysaccharide, shows promise due to its biocompatibility and biodegradability. However, its mechanical, antimicrobial, and antioxidant properties require enhancement. To address these limitations, this study incorporates nano-TiO₂ and Daisy Essential Oil into chitosan to develop a composite film. Key spoilage microorganisms of Actinidia arguta were isolated and identified, with Rhizopus stolonifera reported for the first time as one of the spoilage organisms. The composite film demonstrated significant inhibitory effects against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Bacillus amyloliquefaciens, Aspergillus niger, Neopestalotiopsis clavispora, Aspergillus piperis, and Rhizopus stolonifera. Resistance induction experiments further revealed that CSTD effectively delayed oxidative stress and enzymatic degradation linked to fruit spoilage, significantly extending the shelf life of Actinidia arguta. These findings provide theoretical support for developing effective preservation techniques for Actinidia arguta.