Bioactivity-Incorporated Metabolomics Approach for Efficient Screening of Bioactive Compounds in Kombucha with Varying Citrus Juice and Sugar Levels

Kombucha is gaining global popularity
due to its recognized
health
benefits, supported by testimonials and confirmed through cellular
and clinical studies. Citrus-enriched Kombucha, known for its refreshing
qualities, has seen increased demand. This study examined metabolic
changes during the production of citrus-enriched Kombucha using Hamlin
and LB8–9 Sugar Belle varieties with varying initial sucrose
concentrations. Targeted and untargeted metabolomics revealed that
higher sucrose levels increased concentrations of sugars, organic
acids, and flavonoids. A notable conversion from aromadendrin to quercetin
in the flavonoid synthesis pathway was observed in Hamlin Kombucha,
possibly due to accelerated malolactic fermentation. The bioactivities
of nine compounds, namely, neodiosmin, N-acetyl-dl-tryptophan, limonene, diosmin, indole-3-acetyl-l-aspartic acid, phloretin, (l)-2-aminoadipate, kaempferol
3-rhamninoside, and (R)-mevalonate, were successfully predicted using
bioactivity-incorporated metabolomics, avoiding labor-intensive individual
bioactivity assays. The model’s predictive power was validated
by applying authentic standards in corresponding bioassays. This approach
demonstrates that metabolomics combined with bioactivity assays can
effectively predict the bioactivity of individual compounds in complex
samples, offering a time-saving and less laborious alternative to
traditional fractionation methods.