Improving properties of chitosan/polyvinyl alcohol films using cashew nut testa extract: potential applications in food packaging.

Cashew nut testa, a by-product of cashew nut processing, is abundant in phenolic compounds and exhibits strong antioxidant properties, making it a potential additive for enhancing the antioxidant properties of biodegradable films used in food packaging. This study explores the fabrication of biodegradable chitosan/polyvinyl alcohol films incorporating varying concentrations of cashew nut testa extract (CNTE; 0, 1, 2 and 3% v/v) and evaluates their physical, structural, mechanical, optical and antioxidant properties. The results demonstrate that increasing extract concentration generally increased the thickness, tensile strength, Young's modulus, thermal stability and antioxidant capacity of the films, while reducing the moisture content, swelling degree, elongation at break, and light transmittance.