Development and Characterization of Biocomposite Films Based on Polysaccharides Derived from Okra Plant Waste for...

Polysaccharide-based composite films were developed using mucilage polysaccharides (OLP) and carboxymethyl cellulose (CMC) extracted from okra leafstalk wastes. The rheological properties of biocomposite OLP/CMC film-forming solutions were characterized using the Power-law model, and fabricated films were characterized for their potential food packaging applications. OLP/CMC solutions exhibited pseudo-plastic fluid characteristics and differences in rheological behavior (n, 0.478-0.743), and flow consistency (K, 1.731-9.154) with increasing content of OLP (5 to 30 % w/w of CMC) were associated with variations in the physical, mechanical, and barrier properties of films. Surface hydrophobicity (24%) increased and oxygen (39%) and water vapor (32%) permeability reduced in OLP/CMC films containing up to 10% OLP. Moreover, a higher content of OLP enhanced the antioxidant activity and thermal stability of OLP/CMC films. Subsequently, OLP/CMC was applied as a coating to preserve cherry tomatoes for 14 days at 30 °C. Quality deterioration characterized by high weight loss (22%), firmness loss (74.62%), and discoloration (∆E, 21.26) occurred in uncoated tomatoes and were within unusable/unmarketable limits based on their visual quality score. In contrast, OLP/CMC effectively minimized quality losses, and coated tomatoes exceeded the limit of marketability after 14 days of storage. This study successfully applied value-added polysaccharides derived from okra plant residues for edible food packaging.