Filmes de farinha de mandioca incorporado com nisina e óleo essencial de cardamomo contra patógenos alimentares

Abstract

Active biodegradable films have emerged as sustainable alternatives to synthetic packaging, offering the additional benefit of controlling microorganisms in food. This study aimed to develop and characterize cassava starch-based films incorporated with cardamom essential oil (Elettaria cardamomum, CEO) and nisin, evaluating their physicochemical, antimicrobial (direct contact and vapor), and biodegradation properties. The films were prepared using the spreading method with 3% (w/w) cassava starch, 1.5% glycerol, and different concentrations of nisin (0.1–1.0% w/w) combined with 5 mL of CEO. FTIR, DSC, TGA, UV–Vis, swelling, solubility, and biodegradation analyzes were conducted, in addition to time-kill and vapor phase antimicrobial tests against Staphylococcus aureus, Listeria monocytogenes, Salmonella gallinarum, and S. enteritidis. The FTIR spectra confirmed the incorporation of bioactive compounds, with changes in the O–H and C–H bands, suggesting intermolecular interactions between nisin, CEO, and starch. Thermal analyzes revealed adequate stability (250–350 °C). The release of nisin was temperature-dependent, reaching DO ≈ 0.48 at 40 °C after 72 hours, while the CEO showed a more controlled release. In the direct contact assays, the films containing CEO and nisin exhibited high antimicrobial activity, promoting complete (100%) inhibition of S. aureus, L. monocytogenes, and S. gallinarum, and a partial, yet significant (p < 0.05), reduction of S. enteritidis. In the vapor phase, the films containing CEO demonstrated strong antimicrobial action, resulting in reductions exceeding 96% for all tested bacteria, with complete inhibition of L. monocytogenes and S. gallinarum. The addition of nisin did not alter the action profile in the vapor phase, indicating that the peptide did not interfere with the volatilization or efficacy of the aromatic compounds of the oil. The biodegradation differed significantly (p < 0.05) after 60 days compared to the control, confirming the environmental compatibility of the active films. In conclusion, the cassava starch films incorporated with cardamom essential oil and nisin exhibited excellent physicochemical properties, high antimicrobial activity both by contact and vapor, adequate release behavior, and satisfactory biodegradation, demonstrating high potential as active and sustainable materials for food packaging.