Development of poly (vinyl alcohol)/agar/maltodextrin coating containing silver nanoparticles for banana (Musa acuminate) preservation

Abstract

Banana (Musa acuminate), a popular and abundant agricultural product in Viet Nam supplying for domestic consumption and the export to other countries, is rich in health-beneficial nutrients and minerals. However, banana is potentially susceptible to physical and biological deterioration resulting in remarkable postharvest losses during transportation and storage. Herein, the active nanocomposite coating based on polymeric blend of poly (vinyl alcohol) (PVOH), agar, and maltodextrin incorporated with silver nanoparticles (AgNPs) was applied to prolong the shelf life of banana through the pressurized spraying method. The bananas with and without coating were kept stable at 25 ℃ for 5 days. Changes in appearance and physicochemical properties including colour, respiration rate, weight loss, firmness, titratable acidity, total soluble sugar, total soluble sugar, and solution pH in fruits were also evaluated during storage. The results showed that such nanocomposite coatings may delay the banana ripening and extend the shelf life of banana for 5 days at 25 ℃. The PVOH/agar/maltodextrin/AgNPs nanocomposite coating around the fruits may act as physical barrier resulting in slow decrease in respiration rate, weight loss, softening, titratable acidity, total soluble sugar, and maintaining good appearance of banana (Musa acuminate) as compared to uncoated fruits and those coated with PVOH/agar/maltodextrin during storage period. Furthermore, the results also revealed nanocomposite films prepared from coating solution offered excellent bacterial inhibitory against Escherichia coli and Staphylococcus aureus, as important merit for food packaging application. Moreover, the addition of AgNPs also remarkably increased the flexibility and plasticity of nanocomposite film as compared to PVOH/agar/maltodextrin film. Briefly, the utilization of active nanocomposite coating from PVOH, agar, maltodextrin, and AgNPs could be considered as additional approach for protecting banana (Musa acuminate) from physical and biological deterioration during storage and transportation.