Transforming chamomile (Matricaria chamomilla) infusion into a fermented beverage using sucrose and probiotic lactic acid bacteria

Aromatic and medicinal herbs have long been used worldwide as remedies for a variety of ailments. Among these, chamomile (Matricaria chamomilla) is recognized for its analgesic, anti-inflammatory, antimicrobial, antioxidant and antiseptic properties and is commonly consumed as an herbal infusion. Lactic acid fermentation with probiotic lactic acid bacteria (LAB) offers a practical approach to developing functional beverages with improved sensory and physicochemical properties. In this study, we aimed to evaluate whether chamomile infusion, supplemented with sucrose, could serve as a suitable substrate for fermentation by two well-established probiotic strains: Lacticaseibacillus casei Shirota (DN-114 001) and Limosilactobacillus johnsonii NCC533. We focused on fermentation performance (growth kinetics, acidity, polyphenol content and viable counts) and product stability rather than the detailed nutritional or probiotic metabolite profiles of the strains. Beverages were prepared with 10% and 15% (w/v) sucrose syrups and fermented for 24 h. Statistical analysis revealed significant differences (p < 0.05) between treatments in viable counts (CFU/mL), growth rate (µ), and acidity percentage, with the 10% treatment selected based on sensory evaluation. The viable count averaged 7.43 ± 0.11 log CFU/mL, meeting probiotic criteria (> 6 log CFU/mL). The average growth rate was 0.18 ± 0.006, pH 4.18 ± 0.042, and acidity 0.285 ± 0.0025%. Sanitary quality was acceptable, with no fungi, yeasts, or coliforms detected. Fermentation also significantly increased the total phenolic content. After four weeks at 4 °C, beverages remained viable, with counts between 6.0 and 6.15 log CFU/mL. These results demonstrate the feasibility of producing a refreshing probiotic beverage based on chamomile infusion, with potential as both a functional and shelf-stable product.