Augmenting barrier efficiency in clay-based starch composite films for enhanced packaging sustainability

The pervasive utilization of plastic as a cost-effective packaging material for food has led to environmental concerns, primarily due to its non-biodegradable nature and the ensuing release of carbon dioxide gas that contributes to global warming. In response to these challenges, researchers have shifted their focus toward biopolymers to develop eco-friendly packaging solutions. The present study introduces a novel approach to study the release of micronutrient (Fe) from clay free starch-glycerol film and clay-starch-glycerol composite film. The structural composition and characteristics of the synthesized film are meticulously examined using x-ray diffraction (XRD), ATR, scanning electron microscopy and transmission electron microscopy analytical techniques. Notably, XRD analysis reveals a significant interaction between the starch chains and Mt through hydrogen bonding, indicative of starch and glycerol intercalation within the nanoclay gallery-a phenomenon further corroborated by IR spectra analysis. The nanoclay-infused starch/glycerol composite film exhibits a noteworthy 2.22-fold increase in water vapor permeability compared to clay free film, attributed to the formation of a convoluted diffusion path indicating the enhancement of the barrier performance of starch-based films. Comparative evaluations against earlier studies are undertaken to elucidate the advancements in barrier properties, subsequently elucidating the underlying mechanisms through analytical interpretations. From the release study, the release of Fe2+ from the film with clay was observed to be more prolonged compared to a film without clay. As a result, the Montmorillonite clay-polymer composite film was selected for coating rice seeds using the dip-coating method.