Singlet Oxygen Detection Using Red Wine Extracts as Photosensitizers

Comparison of a Rapid Light-Induced and Forced Test to Study the Oxidative Stability of White Wines

The oxidation processes of white wines can occur during storage and commercialization due to several factors, and these can negatively affect the color, aroma, and quality of the wine. Wineries should have faster and simpler methods that provide valuable information on oxidation stability of wines and allow fast decision-making procedures, able to trigger suitable technological interventions. Using a portable prototype instrument for light irradiations at different wavelengths and times was considered and evaluated on sensorial, spectrophotometric, and colorimetric parameters of white wines. The sensorial analysis revealed that white and light blue were the most significant, after only 1 h of irradiation. The experimental results showed that hydrogen peroxide could enhance the effect of light treatment, allowing a contemporary evaluation of the oxidation stability of wine against light and chemical stresses. As expected, a good correlation (R² > 0.89) between optical density at 420 nm and b* parameter was highlighted. The synergic effect of light and H₂O₂ was also studied on the hydrolyzable and condensed tannins' additions to white wine. The proposed methodology could be used to evaluate the oxidative stability of white wines, but also to evaluate the effect of some oenological adjuvants on wine stability.

Photo-Oxidation of Therapeutic Protein Formulations: From Radical Formation to Analytical Techniques

UV and ambient light-induced modifications and related degradation of therapeutic proteins are observed during manufacturing and storage. Therefore, to ensure product quality, protein formulations need to be analyzed with respect to photo-degradation processes and eventually protected from light exposure. This task usually demands the application and combination of various analytical methods. This review addresses analytical aspects of investigating photo-oxidation products and related mediators such as reactive oxygen species generated via UV and ambient light with well-established and novel techniques.

Curcumin-loaded Pickering emulsion stabilized by insoluble complexes involving ovotransferrin-gallic acid conjugates and carboxymethyldextran

The present work aimed to fabricate antioxidant particle-stabilized Pickering emulsions with outstanding protection of encapsulated nutraceuticals. Antioxidant ovotransferrin-gallic acid conjugates (OTGCONJ) were prepared using the alkaline method, and the electrostatic assembly technique was utilized to construct OTGCONJ-CMD particles with OTGCONJ and carboxymethyldextran (CMD) as the building blocks. After the investigation of the particle size, insoluble nature and intermediate wettability of the OTGCONJ-CMD particles, the OTGCONJ-CMD particles were verified as eligible Pickering stabilizers. Visual observation showed that the stable OTGCONJ-CMD particle-stabilized Pickering emulsion consisted of the emulsified phase alone. Rheological analysis revealed that the Pickering emulsion had a high viscosity and a gel-like structure. In terms of the protective effect, the OTGCONJ-CMD particle-stabilized Pickering emulsion could significantly retard curcumin degradation under UV light. An in vitro digestion study revealed that the OTGCONJ-CMD particle-stabilized Pickering emulsion improved both the extent of lipolysis and curcumin bioaccessibility remarkably, suggesting that the OTGCONJ-CMD particle-stabilized Pickering emulsion was an excellent nutraceutical delivery vehicle. The novel findings in this work could have important implications for the design of nutraceutical-loaded Pickering emulsions with an excellent protective effect and nutraceutical delivery efficiency.

A comprehensive screening shows that ergothioneine is the most abundant antioxidant in the wild macrofungus Phylloporia ribis Ryvarden

The polar and non-polar extracts from the authenticated wild mushroom Phylloporia ribis were separated by hydrophilic interaction liquid chromatography (HILIC) and by reverse phase (RP)-HPLC, respectively. A split valve separated the eluents into two fractions for free-radical scavenging analysis and for structural identification. Forty-six compounds showed scavenging activity of the stable-free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The structures of 8 antioxidants (inosine, caffeic acid, ergothioneine, p-hydroxybenzoic acid, adenosine, 3,4-dihydroxybenzaldehyde, apigenin, and naringenin) are characterized by Mass Spectrometer. Among them, ergothioneine was the most abundant (>65%) and most active antioxidant in P. ribis.