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Desenvolvimento de metodologias verdes e sustentáveis para a obtenção de agentes quimioterápicos a partir de resíduos de processamento de manga (Mangifera indica L.)
(Universidade Federal de São Carlos, 2025-04-02) Zanotti, Karine; Forim, Moacir Rossi; https://lattes.cnpq.br/1234565160573730; https://lattes.cnpq.br/7538221736303396; https://orcid.org/0000-0003-1121-8366
Brazilian agro-industrial production generates alarming amounts of waste. In recent years, mango production has grown significantly, with the state of São Paulo among the largest producers, discarding tons of waste annually. These residues are rich in high-value bioactive compounds, and studies have investigated their antitumor potential due to the presence of secondary metabolites. Given the projected increase in cancer cases, exploring mango waste as a source of new anticancer drugs is a promising approach. Practices aligned with sustainable development should be adopted, with emphasis on using Green and Sustainable Chemistry principles, promoting the creation of products and processes that prevent the generation and use of environmentally harmful substances. Concepts such as biorefinery and circular economy are applicable in this context, utilizing biomass as a raw material to obtain new products. This study aimed to develop green and sustainable analytical methods for obtaining a chemotherapeutic agent through the extraction of secondary metabolites from mango waste. Bioassay-guided experiments on tumor cell lines, combined with spectrometric analyses using test extracts and their fractions, allowed the annotation of the target analytes: gallic acid and methyl gallate. Using chemometric techniques, two extraction methods were evaluated and optimized: homogenization-assisted extraction and microwave-assisted extraction, employing only green solvents such as water and ethanol, and considering the influence of the variables in the extraction. The extracts were analyzed by liquid chromatography coupled with mass spectrometry. The analytes were quantified based on analytical curves, demonstrating selectivity, linearity (R² > 0.999), detection and quantification limits suitable for the linear range, as well as precision (< 2%), accuracy (> 96%), and recovery (> 94%). Among the evaluated variables, ethanol composition (40% v.v⁻¹) in water and the number of extractions (1×) were the most relevant for the optimized extract obtained by homogenization. For the optimized extract obtained by microwave-assisted extraction, ethanol composition (80% v.v⁻¹) in water and temperature (70°C) were the most critical factors. The antitumor properties of test extracts, optimized extracts, and analytical standards of gallic acid and methyl gallate were evaluated in lung and ovarian cancer cell lines, as well as in non-tumor lung cells. The optimized extracts presented lower IC50 values compared to the test extracts, demonstrating greater selectivity for tumor cells. The optimized extract obtained by microwave-assisted extraction was the most promising, with IC50 values of 6.09 and 0.21 μg.mL⁻¹ for lung and ovarian tumor cells, respectively. The optimized extracts showed IC50 values comparable to the drugs cisplatin and doxorubicin, with significantly higher selectivity for tumor cells. A comparison between the extracts and analytical standards revealed a strong synergistic interaction among the matrix compounds. Morphological and clonogenic assays demonstrated that the optimized extracts exhibit cytostatic and cytotoxic profiles, indicating cell death. The results highlight the potential for reusing mango waste to obtain antitumor agents using green analytical methodologies.
Reciclagem de biopolimeros e a formação de substancias não intencionalmente adicionadas: uma abordagem para contato com alimento
(Universidade Federal de São Carlos, 2025-04-02) Paiva, Robert da Silva; Nerín de La Puerta, Maria Cristina; https://orcid.org/0000-0003-2685-5739; Cruz, Sandra Andrea; https://lattes.cnpq.br/9632409046763256; https://lattes.cnpq.br/8013257464586377
The increasing demand for sustainable solutions in the packaging industry has driven the adoption of biodegradable polymers such as poly (lactic acid) (PLA). However, the efficient recycling of post-consumer PLA remains a challenge due to contamination from food residues, cleaning products, automotive substances, and improper disposal. This study addresses the optimization of the PLA recycling process, focusing on the effects of washing, the formation of recycled material for food contact applications. The influence of washing parameters on PLA degradation was evaluated using the Design of Experiments (DoE) methodology. Variables such as sodium hydroxide concentration, temperature, washing time, and surfactant concentration were analyzed. Rheological studies, based on the Cox-Merz rule, revealed that material degradation can be minimized through precise adjustment to these parameters. Specifically, surfactant concentration exhibited a less aggressive effect, even when combined with high temperatures and prolonged times. Conversely, washing time was identified as the most critical factor, particularly when paired with high temperature and sodium hydroxide concentration. The results suggest that adapting washing parameters according to the contamination level of the precursor material enables a more efficient and sustainable recycling process. In parallel, the study examined the formation of Non-Intentionally Added Substances (NIAS) and the presence of contaminants during the recycling process, a critical aspect for meeting international food standards. PLA samples were intentionally contaminated in the laboratory, washed, and mechanically recycled under simulated industrial conditions. Using Headspace Solid-Phase Microextraction with Gas-chromatography coupled Mass spectrometry (HS-SPME-GC-MS) and olfactometric analysis (HS-SPME-GC-O-MS) methods, 34 volatiles compounds were identified, including NIAS such as benzaldehyde, benzyl alcohol, and dimethyl-1,4-dioxane-1,5-dione. Additionally, 14 odor-active compounds were detected and classified into four main groups: toasted, floral, green, and chemical. The study demonstrated a correlation between the recycling stages and NIAS formation, highlighting the importance of rigorous control to ensure compliance with safety standards. The efficiency of the recycling process in contaminant removal was also evaluated following FDA guidelines. PLA samples were contaminated with a standard cocktail composed of benzophenone, tetracosane, heptane, chloroform, and toluene. After washing and mechanical recycling steps, migration tests were conducted using two food simulants under various time and temperature conditions. Analysis using SPME-GC-MS and direct injection (DI-GC-MS) showed a significant reduction in contaminants after the complete recycling cycle, with decreases ranging from 73% to 80% for substances such as tetracosane, heptane, and toluene. In comparison, washing or mechanical recycling alone showed lower removal efficiency. Factors such as the molecular volume of contaminants, type of simulant, temperature, and the interactions between PLA and contaminants directly influenced the results. Theoretical calculations of molecular interactions supported these observations, proving a detailed understanding of the underlying mechanisms. Another focus of the study was mitigating molar mass loss and oligomer formation during the recycling cycle, common challenges for materials intended for direct food contact. To address these issues, carbodiimide (CDI) was added, using co-rotating twin-screw extruders. Results showed that CDI promoted an increase in PLA molar mass and reduced oligomer formation. Moisture played a key role, as carbodiimide reacts both with water molecules, preventing hydrolytic degradation, and with PLA chains, leading to increased molar mass. Oligomer migration tests were performed using three food simulants (ethanol 10%, acetic acid 3%, and ethanol 95%) and analyzed through ultra-high performance liquid chromatography coupled with mass spectrometry (UPLC-QTOF-MSE). Sixteen types of oligomers were identified, with linear oligomers detected in all simulants and cyclic oligomers predominantly found in the ethanol 95% simulant. Theoretical calculations of electronic structure confirmed the observed interaction and migration mechanisms, offering insights into the stability and behavior of the recycled material. The addition of CDI significantly reduced the total oligomer concentration, improving the physicochemical properties of PLA and ensuring its suitability for food contact applications. In conclusion, the study demonstrated that optimizing washing parameters, controlling contaminants and NIAS, and using additives such as carbodiimide are effective strategies for improving PLA recycling. These approaches not only ensure the quality and safety of recycled material but also align with circular economy principles, contributing to the reduction of the environmental impact associated with biodegradable plastics.
Aplicação de amido termoplástico com nanopartículas de quitosana para liberação de nutrientes NPK
(Universidade Federal de São Carlos, 2025-04-02) Franco, Rafael Augusto; Ferreira, Marystela; https://lattes.cnpq.br/4714185516263478; https://orcid.org/0000-0002-9459-8167; https://lattes.cnpq.br/7506955060907326; https://orcid.org/0000-0001-7601-8790
For this study, thermoplastic starch (TPS) films containing NPK nutrients reinforced with chitosan nanoparticles were produced and characterized, aiming at the adsorption of nutrients to them. A device for slow release of NPK nutrientes as prepared. Starch was chosen as the substrate, because it is a biodegradable polysaccharide and extremely abundant in nature. Chitosan has carrier properties on a nanometric scale, due to the increase in its contact surface and the presence of electrostatic groups in its composition. Nanochitosan was obtained through its ionic gelation, in combination with the radical polymerization of methacrylic acid. Using the dynamic light scattering (DLS) technique, an average size of 130.41 ± 1.45 nm and a zeta potential of 24.7 ± 0.7 mV were observed. Then, NPK nutrients were incorporated into the nanochitosan. The particles obtained were analyzed by transmission electron microscopy (TEM), before and after the incorporation of NPK nutrients. These were added to the preparation of thermoplastic starch (TPS) films by wet casting. The thicknesses of the films with and without nanochitosan did not show significant differences. The films with nanochitosan are more resistant to solubilization compared to films containing only NPK. The films were characterized by infrared spectroscopy (FT-IR) and contact angle analysis. The bands that appear with greater absorption intensity in the films refer to the C-O bonds (1600 cm-1) and the C-O-C bonds (between 750 cm-1 and 1000 cm-1) present in the cyclic rings of the starch structure. The contact angle was greater in the film with nanochitosan, indicating that it is capable of making the film less hydrophilic. Its release was studied in the laboratory, through the analysis of percolated samples of simulated soil in the UV-vis spectrophotometer and in situ, through application in the rooting of vegetatively propagated seedlings of the Trema Micrantha species. The percolated samples with the lowest presence of ions were those obtained from the simulated soil containing the films with nanoparticles. Better rooting was observed among the seedlings with nanoparticles. Therefore, the TPS films containing nanochitosan presented better physical properties and beneficial effect on the rooting of vegetatively propagated seedlings.