Herbal extracts have recently gained attention in pharmaceuticals, supplements, and cosmetics. This study explored the impact of Lactic Acid Bacteria (LAB) fermentation on the functional properties of milk thistle and licorice root extracts to develop health-enhancing beverages.
Biological transformation using microorganisms or enzymes was employed to improve the stability and efficacy of these extracts. After 36 h of fermentation, bacterial growth in both extracts surged approximately two-fold. The licorice root extract showed a particularly significant increase in total phenolic content and antioxidant activity, attributed to bacterial enzymes breaking down complex, high-molecular-weight phenolic compounds into simpler, more potent free phenols. Despite a
reduction in total flavonoid content across all samples, this did not indicate a decline in biological activity. HighPerformance Liquid Chromatography (HPLC) analysis revealed a notable increase in silymarin concentration in the milk thistle extract, rising from 0.59 mg mL− 1 to 2.5 mg mL− 1 after fermentation with Lactiplantibacillus plantarum. G
Glycyrrhizic acid in the licorice root extract slightly decreased following fermentation with
L. plantarum, while no significant changes were observed in extracts fermented with L. acidophilus. Cell viability studies during cold storage showed that the bacterial count in the licorice root extract remained within acceptable limits (106 CFU mL− 1) for four weeks, ensuring ongoing health benefits. However, in the milk thistlefermented extract, no viable cells were detected by the third week. These findings demonstrate the potential of LAB-fermented extracts for developing functional beverages with enhanced health benefits and therapeutic
properties.