Organic and conventional apple fermented by Saccharomyces boulardii – The effect of the antioxidant quercetin on cellular oxidative stress

• Published in: British food journal (1966) Vol. 123; no. 2; pp. 520 - 534
• Main Authors: Silva Farinazzo, Fernanda, Bervelieri Madeira, Tiago, Carlos Fernandes, Maria Thereza, Ishii Mauro, Carolina Saori, Bosso Tomal, Adriana Aparecida, Nixdorf, Suzana Lucy, Garcia, Sandra
• Format: Journal Article
• Language: English
• Published: Bradford Emerald Publishing Limited 20.01.2021; Emerald Group Publishing Limited
• Subjects: Acids; Antioxidants; Apples; Cellulase; Chromatography; Dietary minerals; Enzymes; Ethanol; Fermentation; Free radicals; Fruits; Fungi; Milk free; Oxidative stress; Phenolic compounds; Phenols; Probiotics; Pulp; Quercetin; Reactive oxygen species; Saccharomyces boulardii; Sensors; Substrates; Yeast; Brazil; Japan; Germany; Probiotic; Non-dairy; Bioactive compounds; ROS; Fruit fermentation
• ISSN: 0007-070X; 1758-4108
• DOI: 10.1108/BFJ-07-2019-0564

PurposeThe objective of this study was to evaluate the influence of Saccharomyces boulardii on the kinetics of fermentation for organic and conventional apple pulp and to verify the effect of the antioxidant quercetin on the response to cellular oxidative stress.Design/methodology/approachThe kinetic parameters, the content of phenolic compounds, the quantity of quercetin and the antioxidant activity were determined during the fermentation process. The effect of quercetin on cellular oxidative stress was also investigated.FindingsThe content of phenolic compounds, the antioxidant activity and the quercetin concentration were higher in the organic fermented apple pulp (ORG) than in the conventional fermented apple pulp (CON). However, both apple pulps were considered ideal substrates for the growth of S. boulardii, suggesting that they are potentially probiotic. After fermentation, the quercetin concentration in the ORG treatment and YPDQ treatment (YPD broth with 0.1 mg quercetin rhamnoside/mL) increased viability by 9%, while in the CON treatment generated there was an increase of 6% in viability, compared to the YPD control treatment (YPD broth).Originality/valueThe high concentration of quercetin in the organic apple pulp supports the proposal that quercetin reduces the oxidative stress mediated by reactive oxygen species through its antioxidant action on S. boulardii that have similarities to mammalian eukaryotic cells. These findings suggest that fermented organic apple pulp could be consumed as a potential non-dairy probiotic product.