PHENOLIC COMPOSITION OF KOMBUCHA MADE WITH MALVARISCO BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC-DAD)

Kombucha, a traditionally fermented beverage made from Camellia sinensis, has gained attention due to its potential health benefits, primarily attributed to the presence of bioactive phenolic compounds. The incorporation of alternative raw materials, such as malvarico (Plectranthus amboinicus (Lour.) Spreng), and the addition of fruit juices as a flavoring agent, may impart distinct chemical characteristics to the beverage, enhancing its bioactive compound profile. This study aimed to produce kombuchas containing malvarisco and flavored with fruit juices, and to characterize their phenolic profile using High-performance liquid chromatography with diode array detection (HPLC-DAD). Five formulations were prepared: base kombucha, with malvarisco (BK); control kombucha, without malvarisco (CK); and BK flavored with pineapple (AK), pitaya (PK) or watermelon (WK) juice. Fermentation was carried out for 4 days with 15% malvarisco, conditions previously optimized based on fermentation parameters. Chromatographic analysis was performed using a Shimadzu Prominence HPLC system (model SIL-20A), equipped with LC-20AD pumps, a DGU-20A5 degasser, an SPD-M20A detector, and LC Solution 1.22 SP1 software. A total of eight phenolic compounds were identified across the five formulations, with BK and AK exhibiting the greatest phenolic contents. BK exhibited the highest concentration of ferulic acid (10.44 mg/g), a constituent of malvarisco leaves, as confirmed by chromatographic analysis of the raw material (5.62 ± 0.21 mg/g). In AK, the predominant compounds were gallic acid (5.20 mg/g), chlorogenic acid (5.81 mg/g), and caffeic acid (1.04 mg/g), likely derived from malvarisco leaves. Rutin was detected only in CK (0.42 mg/g). The biotransformation of phenolic compounds during fermentation, mediated by enzymes from the Symbiotic Culture of Bacteria and Yeast (SCOBY), may explain the variations in concentrations and the emergence of new metabolites. Thus, chromatographic analysis revealed that the incorporation of malvarisco and the addition of fruit juices, particularly pineapple, significantly influenced the phenolic profile of kombucha, enhancing the levels of phytochemical compounds. This study highlights the potential of HPLC-DAD for optimizing kombucha formulations, ensuring quality and traceability of phytochemical compounds, with direct implications for the development of functional foods.