The production of plant-based fermented beverages has been currently focused on providing a functional alternative to vegan and/or vegetarian consumers. This study primarily targeted the development and characterization of fermented beverages made up of hydrosoluble extracts of oats, almonds, soybeans, Brazil nuts, and rice. The fermentation was carried out by lactic cultures of Bifidobacterium BB-12, Lactobacillus acidophilus LA-5, and Streptococcus thermophilus. Plant extracts were fermented at 37 °C for 12 h, with and without sucrose supplementation. The physicochemical and microbiological stability of the extracts was monitored for 28 days at 5 ± 1 °C. The composition of the fermented beverages was subsequently determined. The pH values measured at the beginning and the end of the extracts' fermentation ranged between 6.45 and 7.09, and 4.10 to 4.97, respectively. Acidity indices, expressed as a percentage of lactic acid, ranged from 0.01 to 0.06 g/100 mL at the beginning of the fermentation, and from 0.02 to 0.33 g/100 mL upon fermentation being concluded. Most fermented extracts achieved viable lactic acid bacteria counts exceeding 106 CFU/mL during storage. Sucrose supplementation did not alter the rate of bacterial growth. The findings showed that the complete replacement of dairy ingredients with water-soluble plant extracts is a potential alternative for developing a functional fermented plant-based beverage.
Keywords: acid lactic bacteria; fermentation; non-dairy; stability.