Development of novel functional fermented goji-based beverages using lactic acid bacteria and yeasts

Abstract Goji berry fruits ( Lycium barbarum L.) are recognized for their health benefits due to the presence of bioactive compounds such as organic acids, polyphenols, and carotenoids. The aim of this study was to develop and characterize novel functional fermented goji berry juice beverages with lactic acid bacteria ( Lactiplantibacillus plantarum ), and yeast ( Saccharomyces cerevisae ), applied in both monoculture and co-culture. All tested strains exhibited good growth in goji juice, maintaining high viability throughout the 15-day fermentation period, with microbial counts remaining above 7 mL − 1 for yeasts and 8 log CFU mL − 1 for lactic acid bacteria. While L. plantarum led to a significant increase in acidity and phenolic content (0.32–0.79% and 4.84–5.77 mg galic acid L − 1 respectively), thereby enhancing antioxidant capacity of the fermented beverages, yeast fermentations were characterized by a sharp decrease in sugars (1.43–2.19 mg 100 mL − 1 ).Carotenoid compounds increased mainly in yeast monocultures (reaching up to approximately 150 mg L −1 ), while remaining significantly lower in the other fermentations, with values ranging roughly between 12 and 30 mg L −1 . Volatile profiling identified 24 compounds, mainly dominated by acetic acid, ethyl octanoate and ethyl decanoate. The chemical composition of the beverages influenced the sensory profile, resulting in reduced sweetness and significant acidic notes, particularly in L. plantarum fermented juices. While this study successfully produced a novel functional goji-based fermented beverage, sensory analysis revealed room for improvement. This suggests that high potential for these innovative beverages to succeed through targeted product optimization, particularly in addressing the growing consumer interest in new functional fermented non-alcoholic drinks.