Singlet Oxygen Detection Using Red Wine Extracts as Photosensitizers

Abstract

Moderate consumption of red wine provides beneficial effects to health. This is attributed to polyphenol compounds present in wine such as resveratrol, quercetin, gallic acid, rutin, and vanillic acid. The amount of these antioxidants is variable; nevertheless, the main beneficial effects of red wine are attributed to resveratrol. However, it has been found that resveratrol and quercetin are able to photosensitize singlet oxygen generation and conversely, gallic acid acts as quencher. Therefore, and since resveratrol and quercetin are some of the most important antioxidants reported in red wines, the aim of this research was to evaluate the photosensitizing ability of 12 red wine extracts through photo-oxidation of ergosterol. The presence of O was detected by ergosterol conversion into peroxide of ergosterol through H NMR analysis. Our results showed that 10 wine extracts were able to act as photosensitizers in the generation of singlet oxygen. The presence of O can damage other compounds of red wine and cause possible organoleptic alterations. Finally, although the reaction conditions employed in this research do not resemble the inherent conditions in wine making processing or storing, or even during its consumption, this knowledge could be useful to prevent possible pro-oxidant effects and avoid detrimental effects in red wines.

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

“…The use of phenols, both condensed and hydrolyzable tannins, is an acknowledged approach to limit some wine faults, such as the appearance of LST [ 9 ], thanks to their antioxidant properties as well as their ability in quenching the singlet oxygen [ 26 , 27 ]. During winemaking, tannins can be added on grape musts during pre-fermentative step or on finished wines as clarifying or stabilization agents.…”

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

“…Furthermore, its low limit of detection (LOD) of about 2.8 nmol/L, and the intense red shift of the phosphorescence signal allows the investigation of very low yields of 1 O 2 produced by photo-sensitizers [59]. In addition to common spectroscopic techniques mentioned above, one can also use more complex detection methods, depending on the available equipment like electron paramagnetic resonance spectroscopy (EPR) [60], nuclear magnetic resonance spectroscopy (NMR) [61] or liquid chromatography [62]. Especially EPR is a useful technique in detecting and identifying ROS, however, it is not a standard technique in the pharmaceutical industry.…”

Riboflavin removal by commercial bentonites and charcoals in white and red wine

“…From the applicative point of view, it would be interesting to understand whether different categories of BENs and CHAs could be used successfully in real wines. Besides white wines, which are commonly preferred for RF studies because of being more subjected to light-struck fault, red wines represent an interesting case of study because, as reported by Lagunes et al (2017), their extracts could act as photosensitizer if exposed to light, generating 1 O 2 , which in turn is able to oxidize other compounds. Moreover, polyphenols make more complex the removal of RF because of the high affinity of phenols to CHAs (Lisanti et al, 2017).…”