Publications by authors named "Luiz Augusto dos Santos Madureira"

The recovery of bioactive compounds is a promising approach for obtaining rich extracts from fruit by-products. This study investigated the influence of Natural Deep Eutectic Solvents (NADES) and Ultrasound-Assisted Extraction (UAE) on the phenolic content, antioxidant capacity, and in vitro antidiabetic activity of Psidium myrtoides by-product. Among eight NADES evaluated based on choline chloride, NADES ChCl:Gly (1:2) was selected for its efficiency in extracting total phenolic compounds (TPC) with high antioxidant capacity.

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Food products composition analysis is a prerequisite for verification of product quality, fulfillment of regulatory enforcements, checking compliance with national and international food standards, contracting specifications, and nutrient labeling requirements and providing quality assurance for use of the product for the supplementation of other foods. These aspects also apply to the berry fruit and berry juice. It also must be noted that even though fruit juices are generally considered healthy, there are many risks associated with mishandling both fruits and juices themselves.

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A simple sample preparation approach employing the dispersive pipette extraction (DPX) technique is proposed to determine twelve polyphenols, including phenolic acids and flavonoids in wines, followed by identification and quantification by LC-MS/MS. The extraction parameters, including sample volume and pH, salting out effect, time and cycles of extraction and desorption, and desorption solvent were optimized using univariate and multivariate designs. The analytical performance was satisfactory, with determination coefficients greater than or equal to 0.

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Seed and peel flours of organic Bordeaux grapes (), containing phenolics and antioxidant capacity, influenced both the composition and properties of a yogurt. The total phenolic content (TPC) of the yogurts containing 3% of grape seed flour (GSFY) and 3% of the mixture of flours (MFY, containing 50% of seed and 50% of peel grape flours, w/w) were 18.800 ± 1.

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This review covers key information related to the effects of pesticides on fetal and child health. All humans are exposed to environmental toxicants, however child's health, due to their high vulnerability, should be of special concern. They are continuously exposed to environmental xenobiotics including a wide variety of pesticides, and other pollutants.

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Three mangroves located in southern Brazil, Carijós (CA), Rio Tavares (RT) and Itacorubi (ITA), with distinct anthropogenic influences, were assessed with regard to the presence of aliphatic and polycyclic aromatic hydrocarbons (PAH). In this study, the n-alkane concentrations ranged from 1.9μg g (CA) to 55.

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A solvent-free method that uses headspace solid-phase microextraction and gas chromatography with flame ionization detection is proposed for the determination of lignin-derived phenols in sediments. The extraction and derivatization conditions for the simultaneous analysis of acetosyringone, acetovanillone, syringaldehyde, vanillin, ferulic acid, syringic acid, vanillic acid, p-hydroxybenzoic acid, and p-coumaric acid were optimized using a central composite design. After optimization, the best results were obtained with the following conditions: exposure of the polyacrylate fiber to the headspace with 60 μL of N,O-bis(trimethylsilyl)trifluoroacetamide as a derivatizing agent for 15 min and then extraction in the headspace of 100 mg of sediment (previously spiked with lignin-derived phenols) for 35 min.

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The practice of large-scale agriculture requires the use of pesticides in order to maximize production. This activity has gained increasing attention in recent years, especially from rural workers, due to the risks associated with long-term exposure to pesticides. To minimize these risks, personal protection equipment (e.

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For the first time, organotin compounds were determined in surface sediment samples collected from São Francisco do Sul, Itajaí-Navegantes and Imbituba Harbors, located in Santa Catarina State, Brazil. Butyltins (BTs) were determined by gas chromatography with a pulsed flame photometric detector (GC-PFPD) after being modified using the Grignard derivatization method. The concentrations of BTs derivatives ranged from n.

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Nonaromatic hydrocarbons and geochemical parameters from 17 sediment-water interface samples were used to assess sources of organic matter in three harbors, located in Santa Catarina State, southern Brazil. The evaluation was based on the molar C/N/P ratios, abundance of resolved nonaromatic hydrocarbons (3.0-25.

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NMR and GC-MS analysis of fractions of the CHCl3 extract of Trichilia catigua bark led to the identification of a mixture of three omega-phenyl alkanes, three omega-phenyl alkanoic acids, five omega-phenyl-gamma-lactones, two alkyl-gamma-lactones, one alkenyl-gamma-lactone and a mixture of fatty acids ranging from C-14 to C-26. Beta-sitosterol, stigmasterol and campesterol as free alcohols were also identified.

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