Produção de filmes compostos de poliestireno com a adição de curcumina e rizoma em pó de Curcuma longa

Abstract

The main function of food packaging is to maintain the quality and safety of food products. Plastic-based materials (polymers) are widely used, since they are inexpensive and are convenient to use. Active films with antimicrobial function are based on the incorporation of additives in the polymer structure during the film production process and aim to reduce, inhibit or retard the growth of the microbiota present, especially on the surface of the packaged food. Research over the last five decades indicates that curcumin has potent antimicrobial activity. The present work aimed to produce films based on polystyrene added curcumin, evaluating its subjective, mechanical, thickness, moisture and antimicrobial properties and to compare these films with polystyrene based films added with Curcuma longa powder rhizome in the same concentrations. The results showed that the films were rigid, with low malleability, irregular shape and with different coloration according to the different formulations. As for moisture and thickness, there was no significant difference between the formulations. It was observed that there is a decrease in tensile strength (MPa) as curcumin addition (formulations F3 and F4), also observed for the addition of Curcuma longa powder rhizome (formulations F5 and F6). The formulation F6 presented the lowest tensile strength value, differing statistically from the F2, F3 and F4 formulations. As for tensile elongation (%), the films had the following groups of similarities: F2=F3=F4 and F2=F3=F5=F6. Regarding the elongation in compression (%) and deformation in the perforation (%) the formulations did not differ statistically. Of the proposed formulations (F3, F4, F5 and F6), none showed antimicrobial activity for strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhimurium bacteria, so it was not possible to compare the difference in antimicrobial activity in relation to the addition of curcumin and rhizome powder of Curcuma longa in the films produced. The lack of antimicrobial activity of the films produced against the bacteria evaluated may indicate that the concentration of the active principle was not sufficient to produce the antimicrobial effect, or the interaction between the polymer and the curcumin and the rhizome powder did not provide the availability of the active principle to act as an antimicrobial agent.