Astaxanthin is a xanthophyll carotenoid showing efficient scavenging ability and represents an interesting candidate in the development of new therapies for preventing and treating oxidative stress-related pathologies. However, its high lipophilicity and thermolability often limits its antioxidant efficacy in human applications. Here, we developed a formulation of lipid carriers to protect astaxanthin’s antioxidant activity. The synthesis of natural astaxanthin-loaded nanostructured lipid carriers using a green process with sunflower oil as liquid lipid is presented. Their antioxidant activity was measured by α-Tocopherol Equivalent Antioxidant Capacity assay and was compared to those of both natural astaxanthin and α-tocopherol. Characterizations by dynamic light scattering, atomic force microscopy, and scattering electron microscopy techniques were carried out and showed spherical and surface negative charged particles with z-average and polydispersity values of ~60 nm and ~0.3, respectively. Astaxanthin loading was also investigated showing an astaxanthin recovery of more than 90% after synthesis of nanostructured lipid carriers. These results demonstrate the capability of the formulation to stabilize astaxanthin molecule and preserve and enhance the antioxidant activity.

To face unmet energy demands, the search for more stable, low-cost, and scalable electrocatalyst materials is imperative. Within this context, single-atom catalysts (SACs) have drawn considerable attention due to their maximum atom utilization. With this idea in mind, we have synthetized a new ultrathin and water-stable 2D Cu-based metal-organic framework (2DCIFs), which presents a notable electrocatalytic activity for oxygen reduction reaction (ORR) in alkaline media without the need of calcination, which makes the difference when compared to most MOF-based electrocatalysts. The designed MOF-based SAC consists of single-atom sites (isolated and accessible Cu) coordinated to imidazole carboxylic ligands, giving rise to Cu-N₄O actives sites confined into a 2D-nanostructured network. This unique structure, along with the ultrathin nature of nanosheets that favors mass transport and electrical conductivity, and the high chemical stability of these 2DCIFs are the key features of the excellent ORR performance, which occurs by a direct four-electron transfer pathway. These good catalytic properties of 2DCIFs have allowed their use as efficient air electrodes in flooded and all-solid-state Zn-air batteries.

Recently, the interest of consumers regarding artisan cheeses worldwide has increased. The ability of different autochthonous and characterized lactic acid bacteria (LAB) to produce aromas and the identification of the volatile organic compounds (VOCs) responsible for flavor in cheeses are important aspects to consider when selecting strains with optimal aromatic properties, resulting in the diversification of cheese products. The objective of this work is to determine the relationship between VOCs and microorganisms isolated (Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Leuconostoc mesenteroides and Lactococcus lactis subsp. hordniae) from raw sheep milk cheeses (matured and creamy natural) using accuracy and alternative methods. On combining Sanger sequencing for LAB identification with Gas Chromatography coupled to Ion Mobility Spectrometry (GC–IMS) to determinate VOCs, we describe cheeses and differentiate the potential role of each microorganism in their volatilome. The contribution of each LAB can be described according to their different VOC profile. Differences between LAB behavior in each cheese are shown, especially between LAB involved in creamy cheeses. Only L. lactis subsp. hordniae and L. mesenteroides show the same VOC profile in de Man Rogosa and Sharpe (MRS) cultures, but for different cheeses, and show two differences in VOC production in skim milk cultures. The occurrence of Lactococcus lactis subsp. hordniae from cheese is reported for first time.