Grape Polyphenols Supplementation for Exercise-Induced Oxidative Stress

Exercise induces free radicals' overproduction and therefore, an enhancement of oxidative stress, defined as an imbalance between the production of reactive species and the intrinsic antioxidant defense. Redox activity of reactive species plays an important and a positive role on exercise adaptation, but these species at very high concentrations have detrimental effects. As a result, the use of antioxidant supplements for reducing oxidative stress can be an effective health strategy to maintain an optimal antioxidant status. In this sense, grapes are an important source of natural antioxidants due to their high content in polyphenols. They have shown antioxidant potential benefits for the reduction of intense exercise effect in athletes of different sport disciplines. Consequently, it is plausible to hypothesize that a strategic supplementation with grape based products may be a good approach to mitigate the exercise induced oxidative stress. The goal of this review is to present the state of the art of supplementation effects with grape beverages and grape extracts on the oxidative stress markers in athletes. The data of polyphenolic dosages, participant characteristics and exercise protocols are reported

Production of Docosahexaenoic Acid and Odd-Chain Fatty Acids by Microalgae Schizochytrium limacinum Grown on Waste-Derived Volatile Fatty Acids

Heterotrophic microalgae are recognized as a source of bioactive compounds. However, there are still some drawbacks for their use at an industrial scale associated with the high cost of glucose, the main carbon source in heterotrophic cultures. In recent years, significant efforts have been made to investigate more sustainable carbon sources to produce biomass. In this study, the capacity of Schizochytrium limacinum to grow on waste-derived volatile fatty acids and the effect that their use produces on biomass and fatty acids profiles were investigated. Acetic, propionic, butyric, valeric and caproic acid were evaluated independently, as well as in a synthetic mixture (VFA). The use of acetic and butyric resulted in a good biomass productivity, while the use of valeric and propionic acid resulted in higher content of odd-chain fatty acids (OCFA), increasingly investigated due to their potential benefits for human health. The use of industrial waste-derived VFA as a potential carbon source was validated through the utilization of biowaste derived effluents from a volatile fatty acid platform. The biomass produced was of 18.5 g/L, 54.0% lipids, 46.3% docosahexaenoic acid (DHA) and 25.0% OCFA, concluding that waste derived VFA can produce DHA and OCFA in a suitable ratio of DHA/OCFA with potential industrial applications.The authors would like to thank the European project VOLATILE. The project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 720777

Study of Unpicked Grapes Valorization: A Natural Source of Polyphenolic Compounds and Evaluation of Their Antioxidant Capacity

Every year great amounts of high-quality wine grapes are left on the vine unpicked, and consequently lost, to control the overproduction in wine areas with limited appellation production yield. In the context of circular bioeconomy, the valorization of these grapes as a potential source of natural antioxidants is of great interest. The study carried out is focused on the polyphenolic profile characterization of different unpicked grape varieties using the ultrasound-assisted extraction technique to extract the polyphenolic fractions. Moreover, the evaluation of the antioxidant capacity by several assays was carried out: oxygen radical absorbance capacity (ORAC), stability of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant capacity (FRAP), cupric reducing antioxidant capacity (CUPRAC) and stability of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) assays. The results showed a strong relationship between total phenolic content and hydroxycinnamic acids (R2 = 0.9088) followed by flavan-3-ols (R2 = 0.8792) and tannins (R2 = 0.7705). The antioxidant capacity of the grapes was dependent on the total phenolic content. These results supply new information for a better understanding of the importance of giving an added value to the unpicked grapes due to their high content of polyphenols. These findings help the wine sector to consider the valorization of the unpicked grapes, classified as wastes, as an interesting source of natural antioxidants to be used as food supplements and with potential applications in the pharmaceutical industry