Probiotic potential of <i>Lactococcus lactis</i> P611 from tropical fruit for functional fermented milk enriched with probiotics and prebiotics

Abstract The novel probiotic strain Lactococcus lactis P611, isolated from papaya, demonstrated robust probiotic properties, including tolerance to simulated gastrointestinal conditions, potent antimicrobial activity against foodborne pathogens, and self-aggregation. Safety assessments confirmed its nonhemolytic nature, antibiotic susceptibility, and low cytotoxicity. When used as a starter culture in milk fortified with wildflower honey and mixed berry powder, the fermented milk product maintained high probiotic viability (&amp;gt;106 log10 Colony Forming Unit (CFU)/ml) and antioxidant activity (66.11%) over 15 days of storage. The addition of mixed berry powder, rich in prebiotics, enhanced the nutritional profile by increasing L-proline content and received positive sensory evaluations (overall preference 7.80). This study highlights the potential of L. lactis P611 as a safe and effective starter for producing functional dairy products with stable bioactivity. The combination of probiotic and prebiotic benefits supports health, consumer appeal, and market potential, warranting further research into fermentation optimization and scalability.