Starter culture growth dynamics and sensory properties of fermented oat drink

• Published in: Heliyon 2023-05, Vol.9 (5), p.e15627-e15627, Article e15627
• Main Authors: Kütt, Mary-Liis, Orgusaar, Kaisa, Stulova, Irina, Priidik, Reimo, Pismennõi, Dmitri, Vaikma, Helen, Kallastu, Aili, Zhogoleva, Aleksandra, Morell, Indrek, Kriščiunaite, Tiina
• Format: Article
• Language: English
• Subjects: Dairy alternatives; Fermented oat drink; Growth dynamics; Sensory profile; Starter consortium; Vegan starter cultures
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2023.e15627

In the present study, an oat drink, a plant-based alternative to dairy products, was developed by fermenting the oat base with different vegan starter cultures. The desired pH below 4.2 was achieved in 12 h, regardless of starter culture used. Metagenomic sequencing revealed that S. thermophilus was the dominating species, ranging from 38% to 99% of the total microbial consortia. At lower pH values, population of L. acidophilus, L. plantarum and L. paracasei continued to increase in fermented oat drinks. Lactic acid was produced between 1.6 and 2.8 g/L. The sensory panel showed that all fermented oat drinks had a sour odor and taste. The volatile compounds identified belonged to the ketone, alcohol, aldehyde, acids, and furan classes. The concentration of the most preferred volatile components, such as diacetyl and acetoin, increased during fermentation. However, sensory evaluation showed that all samples were associated with cereals and not dairy in terms of taste and odor. Rheological analysis showed the formation of weak gel-like structures in fermented oat drinks. Overall, fermentation improved flavor and texture of the product. This study provides a broad overview of the oat drink fermentation process from the perspectives of starter culture growth, microbial consortium dynamics, lactic acid bacteria metabolism, and sensory profile formation. [Display omitted] •A 12 h fermentation with various vegan cultures lowered the pH below 4.2.•The dominant species throughout the fermentation was S. thermophilus.•The fermentation process was homofermentative and lactic acid was produced.•Fermented samples were high in buttery and creamy volatiles.•Fermentation improved and enriched the texture and flavor of the oat drink.