TY - JOUR
T1 - Antioxidant and antimicrobial activities of various leafy herbal teas
AU - Oh, Jungmin
AU - Jo, Heonjoo
AU - Cho, Ah Reum
AU - Kim, Sung Jin
AU - Han, Jaejoon
N1 - Funding Information:
This research was supported by the High Value-added Food Technology Development Program of the Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea (No. 111138-03-1-SB010 ).
PY - 2013/6
Y1 - 2013/6
N2 - We evaluated the antioxidant and antimicrobial activities of various leafy herbal tea (LHT) extracts, including rooibos, green tea, black tea, rosemary, lemongrass, mulberry leaf, bamboo leaf, lotus leaf, peppermint, persimmon leaf, and mate tea. To compare the antioxidant activities of various LHTs, samples of each were extracted with 80 °C water or 20 °C ethanol, and their total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3 ethyl benxothiazoline-6-sulphonic acid (ABTS) radical cation decolorization activity, ferric reducing power, and ferrous ion chelating effect were measured. Green tea ethanol extract showed the highest antioxidant activity in all assays except the ferrous ion-chelating assay. Water extracts of green tea and black tea and ethanol extracts of rosemary, mate, and persimmon leaf teas also exhibited considerable antioxidant potential, followed by the green tea ethanol extract. Minimum inhibitory concentrations (MIC) and minimum lethal concentrations (MLC) were determined to verify the antimicrobial activities of the LHT extracts against two oral pathogens (Streptococcus mutans and Streptococcus sobrinus) and three food-borne pathogens (Listeria monocytogenes, Shigella flexneri, and Salmonella enterica). Among the tested LHTs, green tea ethanol extract had potent antimicrobial activity against all five pathogens, and the mate tea water extract was the most effective against Gram-positive bacteria. Consequently, green tea ethanol extracts had the most powerful antioxidant and antimicrobial properties, suggesting their potential application as a health-promoting functional ingredient or natural preservative in foods.
AB - We evaluated the antioxidant and antimicrobial activities of various leafy herbal tea (LHT) extracts, including rooibos, green tea, black tea, rosemary, lemongrass, mulberry leaf, bamboo leaf, lotus leaf, peppermint, persimmon leaf, and mate tea. To compare the antioxidant activities of various LHTs, samples of each were extracted with 80 °C water or 20 °C ethanol, and their total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3 ethyl benxothiazoline-6-sulphonic acid (ABTS) radical cation decolorization activity, ferric reducing power, and ferrous ion chelating effect were measured. Green tea ethanol extract showed the highest antioxidant activity in all assays except the ferrous ion-chelating assay. Water extracts of green tea and black tea and ethanol extracts of rosemary, mate, and persimmon leaf teas also exhibited considerable antioxidant potential, followed by the green tea ethanol extract. Minimum inhibitory concentrations (MIC) and minimum lethal concentrations (MLC) were determined to verify the antimicrobial activities of the LHT extracts against two oral pathogens (Streptococcus mutans and Streptococcus sobrinus) and three food-borne pathogens (Listeria monocytogenes, Shigella flexneri, and Salmonella enterica). Among the tested LHTs, green tea ethanol extract had potent antimicrobial activity against all five pathogens, and the mate tea water extract was the most effective against Gram-positive bacteria. Consequently, green tea ethanol extracts had the most powerful antioxidant and antimicrobial properties, suggesting their potential application as a health-promoting functional ingredient or natural preservative in foods.
KW - Antimicrobial activity
KW - Antioxidant activity
KW - Functionality
KW - Leafy herbal teas
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U2 - 10.1016/j.foodcont.2012.10.021
DO - 10.1016/j.foodcont.2012.10.021
M3 - Article
AN - SCOPUS:84871663748
VL - 31
SP - 403
EP - 409
JO - Food Control
JF - Food Control
SN - 0956-7135
IS - 2
ER -