Antibacterial Effect of Water-Soluble Tea Extracts on Foodborne Pathogens in Laboratory Medium and in a Food Model

Abstract

The microbial inhibition of foodborne pathogens was determined in brain heart infusion broth with 10% (wt/vol) water-soluble extracts of green, jasmine, black, dungglre, and oolong tea against Escherichia coli O157:H7, Salmonella enterica serovar Enteritidis, Listeria monocytogenes, and Staphylococcus aureus. The mixed culture (approximately 6.0 log CFU/ml), which was composed of the four pathogens, was inoculated into brain heart infusion broth with and without tea extracts. After incubation at 35 degrees C for 0, 1, 3, and 5 days, proper dilution of each sample was spiral plated on each selective agar. Viable cell counts were performed after incubation at 35 degrees C for 24 to 36 h. Green, jasmine, and black tea exhibited an approximately 5.0 log suppression of S. aureus compared with the control from days 1 to 5. Green and jasmine tea also suppressed the growth of L. monocytogenes by approximately 3.0 log CFU/ml on day 5. In contrast, no tea extracts inactivated E. coli O157:H7 and Salmonella Enteritidis. Based on the result in liquid medium, green and jasmine teas of 0.1% (vol/wt) were individually evaluated for their antimicrobial activity against L. monocytogenes and S. aureus in a food model (ground beef) stored at 7 degrees C for 0, 1, 3, 5, and 7 days. Viable cell counts of total bacteria, L. monocytogenes, and S. aureus in ground beef were not significantly different among green and jasmine tea and the control.

New wound dressing polymeric nanofiber containing green tea extract prepared by electrospinning method

“…Different researches have been reported that camellia sinensis has antimicrobial activities against various pathogenic bacteria [1][2][3][4][5][6][7][8][9]. Tea could be categorized into three main types, depending on the level of oxidation, as green tea, oolong tea and black tea [10].…”

Antimicrobial activity of green tea extract against isolates of methicillin–resistant Staphylococcus aureus and multi–drug resistant Pseudomonas aeruginosa

“…Camellia sinensis (C. sinensis), which is one of the most popular beverages worldwide, has been reported to have antimicrobial activities against various pathogenic bacteria [10][11][12][13] , including MRSA [15] and MDR-P. aeruginosa [14][15][16] . However, in Indonesia, there is no study on investigation of the antibacterial effects of C. sinensis against MRSA and MDR-P. aeruginosa.…”

Antimicrobial activity of grape seed extract on Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores in apple juice

“…Natural extracts are less effective in food systems due to the strong interaction between extracts and food components (Kim, Ruengwilysup, & Fung, 2004). Food components such as proteins, lipids, complex carbohydrates, simple sugars and cations can reduce antimicrobial activity.…”