Exploring autochthonous strains with probiotic potential: A comprehensive characterization of functional properties and their application in fermented blueberry-watermelon smoothies

Abstract

Fruit-fermented smoothies enriched with probiotics present a promising alternative for individuals who avoid dairy products. However, identifying suitable probiotic strains poses a critical challenge. This study aimed to characterize five potential probiotic strains: Hanseniaspora opuntiae BIOTEC045, Pediococcus pentosaceus BIOTEC046 and BIOTEC047, and Lactiplantibacillus plantarum LpAv and 73a. The objective was to assess their aggregation and antipathogenic abilities, safety, stress tolerance, and other functional properties. LpAv and 73a displayed the most favorable characteristics. They exhibited high auto-aggregation (>65%), resistance to simulated gastrointestinal conditions (with only 0.3–1.5 log reductions), efficient enzyme production (high levels of β-galactosidase and β-glucosidase), capability to utilize various prebiotics (with maximum optical density values of 1.62–1.81), and production of gamma-aminobutyric acid (1.2 mM), among other features. LpAv and 73a were selected for fermenting blueberry-watermelon smoothies (BWS). During a 7-day storage period at 5 °C, both strains maintained high viability (>9 log colony forming units/mL), while the control samples exhibited spoilage microbial load, highlighting the effectiveness of lactic acid fermentation as a viable bio-preservation technique. Additionally, the BWS retained bioactive compounds and antioxidant activity throughout storage after fermentation, with total phenolic and anthocyanin contents of 0.68–0.73 mg/g and 0.16–0.17 mg/g, respectively. These findings confirm the suitability of BWS as a matrix for fermentation with the selected potential probiotic bacteria. Additionally, the comprehensive characterization of the strains provides valuable insights into their functional properties and contributes to the understanding of their potential health benefits.