Biodegradable chitosan films integrating cinnamaldehyde-loaded yeast glucan microcarriers for postharvest preservation of fruits

Cinnamaldehyde-loaded yeast glucan particles were incorporated into chitosan films . • CY improved the thermal stability, barrier, and mechanical properties of the films. • CS/CY films showed enhanced antibacterial, antioxidant, and UV-blocking activities. • CY enabled sustained release and improved the stability of cinnamaldehyde. • CS/CY2 delayed fruit decay and extended blueberry and strawberry shelf life. Developing multifunctional natural edible films is an effective strategy to reduce postharvest fruit decay and quality deterioration. In this work, cinnamaldehyde was loaded into hollow porous yeast glucan particles (YGPs) derived from Kluyveromyces marxianus to generate CY microcarriers, which were subsequently incorporated into a chitosan matrix to construct CS/CY composite films. The incorporation of CY improved the thermal stability, UV-shielding ability, water vapor and oxygen barrier properties, and mechanical strength of the films, which may be related to intermolecular interactions, including hydrogen bonding, between chitosan and β-glucan-rich YGPs. The CS/CY2 film achieved a water vapor permeability of 4.84 × 10 −11  g s −1  m −1  Pa −1 , an oxygen permeability of 0.84 × 10 −7  g s −1  m −1 , and a tensile strength of 36.91 MPa. Importantly, the hollow porous structure of YGPs enabled sustained cinnamaldehyde release, thereby providing the films with long-lasting antimicrobial activity against Escherichia coli , Staphylococcus aureus , and Botrytis cinerea , together with enhanced antioxidant capacity. In blueberry and strawberry preservation, the CS/CY2 film effectively reduced fungal decay, limited weight loss, delayed firmness reduction, and maintained fruit quality during storage, while exhibiting near-complete biodegradation in natural soil within 20 days. This polysaccharide-based film system incorporating cinnamaldehyde-loaded YGPs provides a promising biodegradable packaging strategy for postharvest fruit preservation. Download: Download high-res image (177KB) Download: Download full-size image