Chitosan/water caltrop pericarp extract reinforced active edible film and its efficacy as strawberry coating for prolonging shelf life

This study focuses on developing and characterizing active and sustainable packaging films made from chitosan (CS), enriched with a novel bioactive extract sourced from water caltrop (Trapa bispinosa Roxb.) pericarp (WCPE). In this study, chitosan (1 % w/v) based biocomposite films were produced using varying concentrations of bioactive extracts (0,5,10,15 and 20 % w/w of CS) from water caltrop pericarp, obtained through ultrasound-assisted extraction. WCPE extract possess excellent antioxidant (89 +/- 1.41 %), higher phenolics (120.48 +/- 4.67 mg GAE g(-1)) and antimicrobial property. Similarly, developed biocomposite demonstrated superior UV barrier (OP600nm similar to 4.30), lower swelling (21.43 +/- 2.61 %), lower moisture content (17.15 +/- 1.82 %), minimum water vapor permeability (1.28 +/- 0.06 g m(-1) day(-1) Pa-1 (x10(-10))), excellent antioxidant capacity (60.41 +/- 1.52 % for DPPH and 70.80 +/- 2.36 % for ABTS), greater phenolics content (168 +/- 4.16 mg GAE/100 g) and good antimicrobial property. Additionally, all formulated coating solutions demonstrated biocompatibility (>85 % cell viability) with BHK-21 fibroblast cells. Finally, the CS-WCPE20 solution was evaluated for its practical use as an edible coating to preserve strawberry, under storage conditions of 20 +/- 5 degrees C and 75 +/- 5 % relative humidity. Developed coating successfully preserved quality attribute such as lower weight loss (similar to 17 %), higher texture (similar to 2.18 N), optimum TSS (similar to 8.44 % Brix), maximum antioxidant quality (similar to 50 % DPPH scavenging activity) and higher color and visual attribute upto 8 days at ambient temperature. Thus, the optimized formulation demonstrates significant potential for use as an active and intelligent packaging solution, effectively extending the shelf life of fruits and vegetables.