PURPLE BASIL (Ocimum basilicum L.) PHENOLIC-RICH EXTRACTS INCORPORATED INTO ARIÁ (Calathea allouia) STARCH BIODEGRADABLE FILMS: ANTIOXIDANT AND PHYSICOCHEMICAL PROPERTIES

Abstract: The development of biodegradable films incorporated with natural bioactive compounds has emerged as a sustainable strategy for active food packaging. Purple basil (Ocimum basilicum L.) is a source of phenolic compounds with antioxidant potential, while Ariá starch (Calathea allouia) represents an underexplored Amazonian starch with technological potential. This study evaluated purple basil extracts and their incorporation into Ariá starch-based biodegradable films. Purple basil leaves were extracted using pure ethanol, ethanol/water (1:1), and hot-water infusion. The extracts were characterized for phenolic compounds by HPLC-DAD, total flavonoids and condensed tannins by spectrophotometry, and antioxidant capacity by the ABTS assay. Biodegradable films were produced using Ariá starch and glycerol with the addition of extracts or infusion and evaluated for bioactive compounds, antioxidant activity, color, solubility, hygroscopicity, water vapor permeability, thickness, and transparency. The ethanol/water extract showed the highest phenolic content (255.41 mg GAE/100 g) and antioxidant capacity (701.89 µmol TE/g), indicating greater extraction efficiency compared with pure ethanol and infusion. After incorporation into films, the ethanol/water formulation maintained the highest phenolic content (150.36 mg GAE/100 g) and antioxidant activity (140.96 µmol TE/g). The incorporation of purple basil extracts modified the film color and physicochemical properties, with reduced water vapor permeability in ethanolic formulations and increased solubility in the ethanol/water film (44.95%). The results demonstrate that purple basil extracts, especially the ethanol/water fraction, enhance the functional properties of Ariá starch-based biodegradable films, contributing to the development of sustainable active packaging materials with antioxidant potential.

Acknowledgments: this work was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil) for the scholarship of Rosane P. F. Chaves (88887.605381/2021-00), and Federal University of Pará (UFPA through PROPESP, Brazil).