DEVELOPMENT OF ACTIVE AND BIODEGRADABLE FILMS FROM OKRA MUCILAGE ENRICHED WITH PINEAPPLE PEEL EXTRACT

The use of vegetable films emerges as a sustainable alternative to conventional plastic packaging, as it is biodegradable, non-toxic and low-cost. Among the biopolymers used, the polysaccharides extracted from okra, rich in pectin and lignin, which form viscous solutions in an aqueous medium, stand out. The addition of antioxidant extracts, such as that of pineapple peel, allows the development of active films, capable of interacting with food and extending its shelf life. In this context, the present study aimed to develop biodegradable and functional films based on corn starch, okra mucilage and pineapple peel extract, evaluating their physical, thermal, morphological and mechanical properties. The films were produced by the casting method, using colloidal solutions poured on silicone plates and dried at 30 °C for 24 hours. The formulations were prepared with 0.240 g/100 mL of okra mucilage, 1.00 g/100 mL of corn starch and 0.50 mL/100 mL of glycerol, adding pineapple peel extract in different proportions: F0 (0%), F1 (1%), F2 (2%), F3 (3%) and F4 (standard formulation with starch and glycerin). The films were characterized for thickness, water vapor permeability (PVA), solubility, color, opacity, tensile strength, elongation at break, scanning electron microscopy (SEM), thermogravimetry (TGA/DTG) and Fourier transform infrared spectroscopy (FTIR). The results showed that the incorporation of pineapple peel extract increased film thickness (F3 = 0.148 mm) and opacity (F3 = 4.79), in addition to promoting greater mechanical strength (F3 = 2.64 MPa) and elongation (F3 = 48.34%). Solubility remained high (95–97%), with a slight reduction in F2 and F4. PVA was superior in F2 and F3, indicating a greater moisture barrier. The films presented homogeneous and continuous surfaces in the SEM, indicating good compatibility between the constituents. TGA/DTG analysis showed stable thermal behavior, with multiple degradation stages attributed to water loss, polysaccharide degradation, and phenolic compounds, with F2 and F3 being the most resistant. FTIR confirmed the incorporation of pineapple peel extract, with shifts and intensity variations in the bands revealing intermolecular interactions and modification of the polymer network. It is concluded that the addition of up to 3% pineapple peel extract results in thicker, more opaque, resistant and elastic films, standing out as the formulation with the best overall performance and potential application in biodegradable and active food packaging.