Incorporação de concentrado de pitaya vermelha em filmes de desintegração oral à base de galactomanana e amido de milho

Abstract

Oral disintegrating films (ODF) represent a promising alternative for the incorporation and release of bioactive compounds, combining administration practicality with potential nutraceutical application. This study aimed to develop ODFs based on galactomannan extracted from Caesalpinia pulcherrima seeds and corn starch, incorporated with different concentrations of red pitaya (Hylocereus polyrhizus) concentrate (PC) to obtain a product with nutraceutical potential. The films were produced by the casting method, using formulations with 0%, 5%, 7%, and 9% PC. The film-forming solutions were analyzed for rheological parameters, and the oral films were evaluated through physical tests: colorimetry, mechanical and mucoadhesive properties, surface pH, FTIR spectra, in vitro disintegration time, moisture content, and oral fluid absorption capacity. Furthermore, total bioactive compounds (betacyanins, betaxanthins, and total extractable polyphenols) and antioxidant activity via the ABTS method were determined. The solutions exhibited pseudoplastic behavior, which is adequate for the plate- casting process. PC incorporation provided an intense red hue to the films and reduced the surface pH from 8.27 (PC-0%) to 5.49 (PC-9%), a range biocompatible with the oral mucosa. Additionally, a decrease in moisture content (16.25%–9.33%), oral fluid absorption capacity, and tensile strength (15.68 MPa–1.75 MPa) was observed, accompanied by an increase in thickness (46.00 μm–159.67 μm) and elasticity (47.49% 126.79%). Mucoadhesive parameters (adhesive force and work of adhesion) decreased with PC addition, indicating that the films tend to detach quickly from the mucosa. FTIR confirmed the successful incorporation of bioactive compounds and indicated intermolecular interactions within the polymeric matrix. The PC-9% formulation exhibited the highest contents of betacyanins (474.83 μg·g−1), betaxanthins (290.03 μg·g−1), and polyphenols (12.72 mg GAE·g−1), consequently showing the highest ABTS radical scavenging capacity (92%). However, this formulation was the stickiest and showed an excessive disintegration time (243.24 s), exceeding standard limits. Thus, formulations containing 5% and 7% PC achieved the best balance between technological and functional properties, demonstrating the high nutraceutical potential of these ODFs.