Enhanced aroma and flavour profile of fermented Tetragonula pagdeni Schwarz honey by a novel yeast T. delbrueckii GT-ROSE1 with superior fermentability

Beside a source of bioactive compounds, honey represents untapped-reservoir of beneficial microbes. Next generation sequencing technology was applied to aid the discovery of newly-isolated flavour yeast Torulaspora delbrueckii strain GT-ROSE1 from honey samples. Owing to the presence of natural duplicate regulatory sites in aromatic genes, it was used to create value-added fermented honey with unique aroma-flavour profile. This osmophilic strain could assimilate different carbons and tolerated to low pHs, high ethanol and sugars, exhibiting useful traits for food and alcoholic fermentation of sugar-based industries. Global analysis of aroma-flavour profile revealed higher total concentrations of key compounds after fermentation by GT-ROSE1, compared to commercial wine yeasts. Twenty-four volatile compounds were identified using a nontargeted HS-SPME-GC-MS method. High odour activity values and quantitative sensory analysis indicated fruity and rose flowery aroma of key compounds nonanol and 2-phenylethanol, respectively. Importantly, fermented Tetragonula pagdeni Schwarz honey with observed excellent antioxidant property displayed appealing characteristic of enhanced 2-phenylethanol of rose-like flavour with odour threshold of 16.08. Thus, flavour yeast could be used to improve chemical content and enhance sensory value of local food products.