Avaliação das propriedades mecânicas e fotoprotetoras de filmes biopoliméricos contendo extrato produzido a partir de bagaço de azeitona

Abstract

The southern region of Brazil has stood out in olive oil production, generating olive pomace rich in bioactive compounds, such as carotenoids and chlorophylls. In this sense, this work explored the potential of the pomace by extracting natural pigments to improve the barrier properties of biopolymer films, with potential application in cosmetic packaging. Initially, the olive pomace was dried in an oven, subjected to pneumatic separation in a fluidized bed to separate a pulp-rich fraction, ground in an analytical mill, sieved, and characterized. The olive pomace pulp showed a moisture content of 4.70%, with total chlorophyll at 418.92 µg/g, chlorophyll a at 25.63 µg/g, chlorophyll b at 389.43 µg/g, and total carotenoids at 66.01 µg/g. The antioxidant activity was 72.91%, with total phenolic compounds at 3.95 mg GAE/g ss. The apparent specific mass was 352.7 kg/m3 and the real specific mass was 1250 kg/m3. Photoprotective extracts from the ground pulp were obtained using ethanol as a solvent under constant agitation. The analysis of the extracts revealed total chlorophyll at 615.75 µg/g, chlorophyll a at 352.30 µg/g, and chlorophyll b at 263.45 µg/g. Biopolymer films based on potato starch were prepared without (control sample) and with the presence of chlorophyll extracts. The control films and those added with 30% and 40% ethanolic extract showed some differences among themselves, respectively: the thickness increased from 0.19 mm to 0.28 mm and 0.34 mm, respectively; the tensile strength rose from 3.08 MPa to 3.31 MPa and 11.76 MPa; and elongation varied from 341% (control sample) to 437% (with 30% extract) and 289% (with 40%). In terms of color, ΔE was 77.49 with 30% extract and 6.61 with 40%, with a more pronounced yellow hue at 40%, indicating the presence of carotenoid pigments, with antioxidant and photoprotective potential. These results demonstrated the potential of biopolymer films based on potato starch, enriched with photoprotective olive pomace extract for industrial applications, such as cosmetics, enhancing the functionality and aesthetics of the packaging. Further studies should be conducted to better highlight the antioxidant and barrier properties of these films, especially concerning photoprotection.