Determining the effect of plant extracts on the development and characterization of biodegradable composite films from Corypha umbraculifera L. stem starch

Films and coatings fabricated with renewable biopolymers and antimicrobial agents have attracted research interest owing to their contribution to food safety and biodegradability. The study aims to determine the effect of natural plant extracts from the leaves of curry tree, neem, tulsi, and Mexican mint for developing and characterizing biodegradable composite films of talipot starch and carboxymethyl cellulose (CMC) matrices. Talipot starch isolated from the stem of talipot palm (Corypha umbraculifera L.) is an underutilized source of starch with a high yield (76%). All composite films were prepared using the solution blending-casting method. The dominant properties of biodegradable film such as structural, morphological, barrier, and antimicrobial properties were studied. The relative crystallinity of composite films comparatively increased with native talipot starch film. The surface of talipot starch film made with CMC and plant extracts showed higher roughness and opacity. Incorporation of plant extracts into talipot starch and CMC matrices decreased water vapor permeability (WVP) and oxygen permeability (OP), indicating improved barrier properties of the films. Antimicrobial activity assessed by the inhibition zone method showed that composite films exhibited excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. These results revealed that biodegradable composite films from non-conventional starch of talipot palm could potentially substitute the single-use petroleum-based films and can be used as bioactive packaging materials for food applications.