Development of fruit-based drinks fortified with probiotics, Spirulina platensis and pea protein

The aim of this study was to develop fruit-based drinks enriched with plant-based proteins [Spirulina platensis biomass (0.25%, w/v) and pea protein isolate (5.83%, w/v)] and probiotics (Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, and Lactiplantibacillus plantarum or their combination) (1%, v/v). The drinks were fermented with probiotics at 37 °C for 24 h before being stored at 4 °C for 90 days. They were then evaluated for microbiological, physicochemical and sensory properties after fermentation and during storage. The probiotic viability in the fermented drinks was between 8.67 and 9.61 log CFU/mL after fermentation. During storage period, the viable probiotic cell counts in the drinks were greater than 7.36 ± 0.09 log CFU/mL, while the pH, titratable acidity, total sugar, protein and total phenolic contents of the probiotic drinks were in the range of 3.44–3.96, 0.69–1.37 g lactic acid/100 mL, 9.14–9.62 g/100 mL, 4.39%–4.70%, and 1053.00–1415 mg GAE/L, respectively. Sensory evaluation demonstrated that the drinks enriched with probiotics were equally or more favourably liked than the control sample during the storage. In general, the sample fermented with L. casei (MC) exhibited the highest probiotic, total phenolic content and antioxidant activity at the end of storage. Conversely, the sample fermented with L. rhamnosus (MR) had a high protein content at the end of storage. Consequently, the enrichment of fruit juices with probiotics and plant proteins offers a new alternative to the functional food market.