Sónia Patrícia Marques Ventura

The growing demand for functional foods has increased interest in natural ingredients with nutritional and bioactive properties for dairy applications. This study evaluated Gracilaria gracilis (G. gracilis) aqueous extract and White Chlorella as functional ingredients in yogurt. Three formulations were prepared: control yogurt (CY), yogurt containing G. gracilis extract (GY), and yogurt containing both G. gracilis extract and White Chlorella (GWY). Proximate composition, total phenolic content (TPC), antioxidant activity, color, pH, texture, and water-holding capacity (WHC) were assessed after fermentation and over 21 days of refrigerated storage. GY exhibited a pink coloration that was clearly perceptible relative to the control (ΔE* > 3) and remained stable throughout storage (ΔE* < 0.6 relative to Day 1). GY also showed lower firmness, consistency, cohesiveness, and WHC than CY, differences that may be attributable, at least in part, to the dilution introduced with the aqueous extract. Compared with GY, GWY contained 32% more protein (3.66 vs. 2.78 g/100 g) and showed higher firmness, consistency, and WHC, in some cases reaching values comparable to those of the control. TPC did not differ significantly among formulations (p > 0.05), while the antioxidant activity of both supplemented yogurts was lower than that of the control. Instrumental color changes during storage were small in magnitude, while texture remained generally stable across the 21-day storage period.

Poly(lactic acid) (PLA)-based membranes are attractive biodegradable platforms for the development of functional polymer membranes, but their use in ion-transport applications remains limited by the difficulty of incorporating and retaining mobile ionic phases without compromising membrane integrity. In PLA–ionic liquid (IL) systems, weak polymer–IL interactions can promote phase separation, liquid loss and mechanical instability, particularly at high IL contents. In this work, these limitations are addressed through controlled membrane processing and microstructural organisation. Two imidazolium-based ILs, 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([C₄C₁im][CF₃SO₃]) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₄C₁im][NTf₂]), were incorporated into PLA membranes to investigate how IL chemistry and composition govern microstructure, liquid-phase retention, water sorption and functional performance. The results show that, after exposure to liquid water, the amount of IL effectively retained within the PLA matrix reaches a plateau of approximately 30 wt.%, corresponding to about one third of the membrane volume. This retained fraction preserves membrane integrity while enabling the formation of confined IL-rich domains that contribute to ionic transport under humid conditions. At equivalent IL contents, PLA–[C₄C₁im][NTf₂] membranes generally display higher ionic conductivity, consistent with the higher intrinsic mobility of the NTf₂-based IL, although their accessible compositional window is limited by mechanical instability. By contrast, PLA–[C₄C₁im][CF₃SO₃] membranes tolerate higher nominal IL loadings and benefit more strongly from water-assisted ion transport, reaching ionic conductivities of up to 3.21 × 10⁻² S cm⁻¹ at 98% RH and 94 °C. PLA–[C₄C₁im][NTf₂] membranes also show selective and time-dependent antibacterial activity, particularly against Gram-negative bacteria. Combined thermal, sorption, morphological, electrical and antimicrobial analyses demonstrate that membrane performance is primarily governed by IL confinement, accessibility and water-assisted transport, rather than by strong polymer–IL interactions. Overall, this work establishes processing-induced microstructure as a key parameter controlling IL retention, water uptake and ion transport in PLA-based composite membranes, providing design guidelines for biodegradable ion-conducting membranes with additional antimicrobial functionality.

From batch to flow: (Deep) eutectic solvents for sustainable biomass valorization.

Curcumin is a promising natural drug for the treatment of various diseases ranging from cancer to Alzheimer’s. However, a major hindrance in its use as a drug is its low aqueous solubility, rapid degradation, and poor cellular uptake. In recent years, the use of ionic liquids (ILs) in biomedical applications has gained significant attention due to their unique properties and tunability. In this study, we demonstrate the capacity of the superbase ionic liquid (SBIL) 5-Methyl-1,5,7-triaza-bicyclo[4.3.0]non-6-enium acetate [mTBNH][OAc] to dissolve highly hydrophobic and water-insoluble curcumin. An optimized concentration of 4 mol.kg^-1 of SBIL was used to dissolve 3.5 mg.g^-1 of curcumin, resulting in a formulation (curcumin/SBIL) that could be easily dispersed in an aqueous medium. Compared to the aqueous solubility of curcumin alone, the curcumin/SBIL formulation exhibited almost an 8,000-fold increase in solubility, also demonstrating a reduction of ~ 60% of human triple-negative breast cancer epithelial cells (MDA-MB-231) viability with only 10 µg.mL^-1 of curcumin (the active compound), without any cytotoxic effects on non-tumorogenic mouse fibroblasts (L929). Our study presents a straightforward methodology for improving the solubility and bioavailability of curcumin, which holds promise for its clinical application as an effective anti-cancer drug.

Due to the widespread use of ionic liquids (ILs) in various applications and their frequent combination with salts in processes or products, mixtures of ILs and salts are likely to be present in aquatic environments. The present study aimed to assess the combined ecotoxicity of mixtures of cholinium-based ILs (cholinium bicarbonate, benzyldimethyl(2-hydroxyethyl)ammonium chloride, cholinium bitartrate and cholinium dihydrogencitrate) and salts (potassium phosphate tribasic and sodium citrate dihydrate) to the microalga Raphidocelis subcapitata, a highly sensitive microalgal species. The 96 h-EC₅₀ values for the endpoint yield increased as follows: [Chol][DHCit] (EC₅₀ = 85.2 mg L⁻¹) < [Chol][Bit] (EC₅₀ = 110.8 mg L⁻¹) < [Chol][Bic] (EC₅₀ = 310.5 mg L⁻¹) < [BzChol]Cl (EC₅₀ = 766.3 mg L⁻¹), generally following the expected increase of ecotoxicity with increased hydrophobicity. Both CA and IA models could describe the observed ecotoxicity, but a better fit was achieved with the CA model, with antagonistic interactions observed in 5 of the 8 tested mixtures. The salt K₃PO₄ was found to be less ecotoxic than NaCit·2H₂O and, simultaneously, to promote stronger antagonism, and is thus recommended to be used in future processes or product design with cholinium-based ILs, hence supporting the advancement of green chemistry. Synergism was not significant in any mixture, despite being observed under specific conditions, particularly when the IL was dominant in the mixture and above 1 TU. The antagonism observed for most of the mixtures, associated with the hormesis observed for all mixtures, suggests that mixtures of ILs and salts will likely be less environmentally hazardous than predicted based on their individual toxicities. Since ILs commonly present high water solubility and good stability, further studies addressing the effects of mixtures with ILs should be performed, contributing to improving the risk assessment of ILs.

LSCs enable large-area energy-generating windows with thermometric abilities. A scalable bacteriochlorophyll prototype offers sustainable transparency and efficiency.

In this work, a singular system capable of interacting with the entire visible region of the solar spectrum is produced by combining carbon dots (CDs) and chlorophyll (Chl) pigments, entirely derived from the microalga Chlorella pyrenoidosa. The process involves the digestion of the C. pyrenoidosa cellular wall in an acetic acid:cholinium chloride (AA/ChCl) solvent, followed by a microwave reaction. The resulting CDs exhibit excitation and emission maxima at 461 and 528 nm, respectively. The Chl centers enable a secondary photoluminescence (PL) process, thus ensuring that the as-prepared CDs/Chl system (CDCS) can also interact with the farther red region of the visible spectrum. The luminescence properties of CDCS are concentration-dependent, undergoing a blue shift with dilution. Confocal microscopy provided insights into the protection of Chl pigments throughout the process. Furthermore, the consequences arising from the addition of poly­(ethylene glycol) oligomers (PEG-200) are also analyzed. The results demonstrate that the interaction between CDCS and PEG-200 significantly modifies the PL intensity and emission wavelengths, especially at higher PEG-200 concentrations. This suggests that PEG-200 can act as a modulating agent, stabilizing and even preventing the CDs’ fluorescence quenching while also affecting the PL properties of Chl. This work presents interesting possibilities for the development of multifunctional luminescent systems derived from microalgae biomass by addressing how these microorganisms can function not only as precursors in the formation of advanced functional materials but also as an integrated component of these systems. As an added benefit, a luminescent solar concentrator (LSC) was fabricated, revealing photostability, as well as optical and power conversion efficiency values of 11 and 0.2%, respectively, values comparable to state-of-the-art CD-based LSCs.