Desenvolvimento de filme biodegradável ativo com extrato das cascas de tucumã-do-Amazonas (Astrocaryum aculeatum Meyer)

Abstract

The rising concern about pollution from excessive fossil-based packaging materials, particularly single-use plastics, has prompted research into the creation of active biodegradable biofilms. This study aimed to incorporate an extract from the peels of Astrocaryum aculeatum Meyer, commonly known as tucumã-do-Amazonas, into a starch-based matrix to produce an active biodegradable biofilm. The biofilms, which were composed of starch, glycerol, and water, were prepared using the casting method. The hydroalcoholic extract from tucumã peels was incorporated at levels of 0%, 5%, 10%, and 15%, based on the total volume of water used. The developed films were evaluated for thickness, moisture content, solubility, total phenolic content, antioxidant activity, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), water contact angle, color, UV-light barrier capacity, and transparency at 600 nm. Mechanical properties were assessed through tensile strength, Young’s modulus, and elongation at break. Surface morphology was examined using scanning electron microscopy (SEM), and thermal properties were analyzed under a nitrogen atmosphere. Biodegradability was assessed over three months. The resulting films were flexible and easy to handle. Control films had a thickness of 0.32 mm, while those containing extract ranged from 0.25 to 0.28 mm. Moisture content varied significantly among samples, indicating that the incorporation of extract affected the films’ barrier properties. Control films showed the lowest water solubility, at 17.45 ± 0.81%. Total phenolic content was detected only in films containing 10% and 15% extract. The 15% extract samples exhibited antioxidant activity of up to 90%, a favorable result for the intended application. FTIR analysis revealed similar spectral profiles among samples, indicating no significant shifts in principal peaks. XRD results confirmed that the crystalline structure remained unchanged. Water contact angle measurements indicated that the films were hydrophilic. Films containing extract exhibited UV-light reduction capacity, offering photodegradation protection for packaged foods. Mechanical testing revealed a significant decrease in tensile strength and elasticity upon incorporation of the extract. However, elongation at break increased by more than 1500% compared to control samples. SEM analysis revealed the presence of granules and insoluble materials, suggesting incomplete starch gelatinization. Extract-containing films exhibited thermal stability up to 80 °C, while control films were stable up to 45 °C. Biodegradability tests revealed fungal growth on samples containing extract as early as the first week under soil coverage. In conclusion, incorporating bioactive compounds from tucumã peels imparted antioxidant properties to the biofilms developed. With minor adjustments to the formulation, it is possible to create a high-quality product that supports the circular economy and sustainability in the state of Amazonas, while also enhancing the value of the residues from Astrocaryum aculeatum.