The Production of Bioactive Hydroxytyrosol in Fermented Beverages: The Role of Must Composition and a Genetically Modified Yeast Strain

© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Hydroxytyrosol (HT) is a well-known compound for its bioactive properties. It is naturally present in olives, olive oil, and wine. Its presence in wines is partly due to its production during alcoholic fermentation by yeast through a hydroxylation of tyrosol formed through the Ehrlich pathway. This work aims to explore the influence of yeast assimilable nitrogen (YAN) and glucose content as precursors of HT formation during alcoholic fermentation. Commercial Saccharomyces cerevisiae QA23 and its metabolically engineered strain were used to ferment synthetic must. Each strain was tested at two different YAN concentrations (210 and 300 mg L−1) and two glucose concentrations (100 and 240 g L−1). This work confirms that the less YAN and the more glucose, the higher the HT content, with fermentations carried out with the metabolically engineered strain being the ones with the highest HT content (0.6 mg L−1).

This research was funded by projects (PID2019-108722RB-C32 and PID2019-108722RB-C31) funded by MCIN/AEI/10.13039/501100011033/and FEDER Una manera de hacer Europa, and by the project P18-RT-3098 funded by Junta de Andalucía (Consejería de Economía y Conocimiento) and the Universidad de Sevilla for the M.G.-R. predoctoral contract PIF.

Peer reviewed