Polyphenolic profiles, antioxidant capacity, and antibacterial activity of green tea, matcha tea, black tea, and yerba mate extracts
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Kuupäev
2025
Kättesaadavus
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Elsevier
Abstrakt
Tea is widely consumed for its beneficial bioactive compounds with potential health benefits. This study investigated the polyphenolic profiles, total antioxidant capacity (TAC), and antibacterial activity of aqueous and 30 % ethanolic extracts prepared from commercially available green tea, matcha tea, black tea, and yerba mate.
The polyphenolic profiles were analyzed using HPLC-DAD-MS, with 28 compounds identified and semiquantified
based on extracted ion chromatogram areas. Total polyphenol content (TPC) was quantified as
gallic acid equivalent using external calibration and UV chromatogram area at 280 nm. TAC was measured by the
DPPH and Folin-Ciocalteu methods. Minimum inhibitory concentrations (MICs) against Listeria monocytogenes,
Staphylococcus aureus, Escherichia coli, and Campylobacter jejuni were determined using the broth microdilution
method. Mate ethanolic extracts had the highest TPC (5.16 ± 0.02 mg GAE/mL), followed by green (4.68 ± 0.08
mg GAE/mL), black (4.26 ± 0.08 mg GAE/mL), and matcha tea extracts (3.55 ± 0.01 mg GAE/mL). The hierarchical
dendrogram showed that mate extracts differed significantly (p < 0.001) from the others, containing
mainly chlorogenic acids and giving similar TAC, and MIC results for both aqueous and ethanolic extracts. Tea
extracts exhibited the highest proportions of flavanols, mainly epigallocatechin, epicatechin gallate, and epigallocatechin
gallate, which showed strong negative correlations (rS = 0.7 to 0.8) with MICs against E. coli
and strong positive correlations (rS = 0.7 to 0.9) with TAC. S. aureus was the most susceptible to the studied plant
extracts demonstrating the lowest MIC values ranging from 0.06 to 0.27 mg GAE/mL. Green tea extracts showed
the strongest TAC and antibacterial activity. These findings highlight the potential of tea and mate extracts as
natural antibacterial and antioxidant agents for food applications.
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Märksõnad
tea, mate, extracts, polyphenols, antioxidant, antibacterial, articles