Search Results (3)

Sargassum filipendula is a marine macroalgae, also known as brown algae. These species contain significant amounts of polysaccharides, such as alginates, and phenolic compounds, including phlorotannins, with excellent biological properties. This study evaluated the extraction of bioactive compounds from the residual biomass of Sargassum filipendula using deep eutectic solvents based on alkanol amines combined with polyols. The residual biomass presented a content of 7.36% protein, 1.11% lipids, 20.51% ash, 14.88% moisture, 50.25% total fibers, and 5.89% alginate. Preliminary screening identified N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30:1) and N, N-(dimethylamino)-ethanol:1,3-propanediol (1.83:1) as the most efficient solvents for the extraction of bioactive compounds. The optimization process showed that the temperature and solid–liquid ratio significantly influenced (p < 0.05) the extraction of total phenolic compounds, phlorotannins, and the content of photosynthetic pigments. Intermediate temperatures (74.4 °C for N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30:1) and 68.4 °C for N, N-(dimethylamino)-ethanol:1,3-propanediol (1.83:1), and a lower solid-to-liquid ratio (0.03) were optimal conditions to extract the low-pigment phlorotannins selectively. In contrast, higher temperatures (120 °C) maximized the extraction of phlorotannins and photosynthetic pigments. N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30) extracted 110.64 mg PGE/g phlorotannins and 78.15 mg GAE/g phenolics, while N, N-(dimethylamino)-ethanol:1,3-propanediol (1.83:1) produced 21.57 mg PGE/g and 72.89 mg GAE/g, respectively. The extraction of photosynthetic pigments reached a maximum yield at 120 °C, using N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30:1), with a content of 21.61 µg/g of chlorophylls and 38.11 µg/g of pheophytins, while N, N-(dimethylamino)-ethanol: 1,3-propanediol (1.83:1) provided content of 17.76 µg/g and 36.32 µg/g, respectively. The extracts exhibited antioxidant activity with 0.69 mg TE/mL in scavenging DPPH radicals, 24.42 mg TE/mL in scavenging ABTS radicals, and 2.26 mg TE/mL of iron-reducing antioxidant power. These results demonstrate the potential of DESs for the sustainable recovery of bioactive compounds from Sargassum filipendula residual biomass. Full article

The adsorptive removal of Bisphenol A (BPA) with the PE meshes photografted with 2-(dimethylamino)ethyl methacrylate (DMAEMA) was performed by varying the grafted amount, pH value, BPA concentration, and temperature, and the adsorption performance was correlated by the equilibrium, kinetic, and isotherm models. In addition, the regeneration of DMAEMA-grafted PE (PE-g-PDMAEMA) meshes was discussed from the repetitive adsorption/desorption process. The adsorption capacity had the maximum value at the grafted amount of 2.6 mmol/g and at the initial pH value of 8.0. The increase in the protonation of dimethylamino groups on grafted PDMAEMA chains and the dissociation of phenol groups of BPA present in the outer solution during the adsorption process results in the increase in BPA adsorption. The adsorption process followed the pseudo second-order equation. The BPA adsorption was enhanced by increasing the BPA concentration and the equilibrium data fit to Langmuir equation. The adsorption capacity stayed almost constant with the increase in the temperature, whereas the k₂ value increased against the temperature. These results comprehensively emphasized that BPA adsorption occurred through the chemical interaction or ionic bonding of a BPA anion to a terminal protonated dimethylamino group. Desorption of BPA increased by increasing the NaOH concentration and BPA was entirely desorbed at more than 20 mM. The cycle of adsorption at pH 8.0 and desorption in a NaOH solution at 100 mM was repeated five times without loss or structural damage. These results indicate PE-g-PDMAEMA meshes can be used as a regenerative adsorbent for BPA removal from aqueous medium. Full article

This study introduces a novel method for detecting free glycidol and total free monochloropropanediol (MCPD) in fish and krill oil. Before analysis on high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS), p-(dimethylamino)phenol was used for derivatization of these compounds, enabling the sensitive determination of these contaminants. The sample preparation procedure includes a simple, efficient pretreatment using NaCl aqueous solution extraction and C18 sorbent cleanup (for demulsification), distinguishing glycidol from MCPD under varied reaction conditions for derivatization (weak acidic and strong alkaline aqueous environments). This approach shows broad linearity from 1 to at least 256 ng·mL⁻¹, improved sensitivity compared to standard GC-MS methods, with the limit of detection (LOD) and limit of quantification (LOQ) for MCPD and glycidol in both oil samples verified at 0.5 ng·mL⁻¹ and 1 ng·mL⁻¹, respectively. Different from previous HPLC-MS methods for direct detection of glycidol esters or MCPD esters, this is the first HPLC-MS method used for the detection of free glycidol and total free MCPD in edible oil. Furthermore, this method can be potentially developed for glycidol or monochloropropane diol esters, which is similar to the current official methods adopted for indirect detection of these contaminants in different food matrices. Application of this detection method to real dietary supplements (fish oil and krill oil) revealed MCPD residues in fish oil (maximum detected: 32.78 ng·mL⁻¹) and both MCPD (maximum detected: 2767.3 ng·mL⁻¹) and glycidol (maximum detected: 22.2 ng·mL⁻¹) in krill oil, emphasizing its effectiveness and accuracy for assessing contamination in these supplements. Full article