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Antibacterial effect of crude water‐soluble arrowroot ( Puerariae radix ) tea extracts on food‐borne pathogens in liquid medium
Author(s) -
Kim S.,
Fung D.Y.C.
Publication year - 2004
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2004.01582.x
Subject(s) - food science , radix (gastropod) , chemistry , water soluble , antibacterial agent , biology , microbiology and biotechnology , botany , antibiotics , organic chemistry
Aims: To evaluate the effect of crude water‐soluble arrowroot tea extracts on microbial growth of food‐borne pathogens in liquid medium and to confirm the damage to bacterial cells using Transmission Electronic Microscopy (TEM). Methods and Results: Inhibition of growth of Escherichia coli O157:H7, Salmonella enterica serovar Enteritidis, Listeria monocytogenes and Staphylococcus aureus was investigated using Brain Heart Infusion (BHI) broth containing 0 (control), 0·63, 1·25, 2·5 and 5·0% (w/v) arrowroot tea. Bacterial cell counts were performed on specific selective agar on days 0, 1, 3 and 5. BHI containing 5·0% arrowroot tea extract showed a 6–7 log suppression of growth for all test strains on days 3 and 5, compared with the control. Even 0·63% arrowroot tea effectively inhibited microbial growth of all test strains on day 5. TEM images of the samples treated with 5·0% arrowroot tea revealed the rupture of cell walls and nonhomogeneous disposition of cytoplasmic materials within treated bacteria. Conclusions: Crude water‐soluble arrowroot tea extract strongly inhibited microbial growth of all test pathogens in liquid medium. Significance and Impact of the Study: Water‐soluble arrowroot tea extract has the potential to be used directly on foods or as a spray on the surfaces of food handling and processing facilities in order to prevent microbial growth of both Gram‐negative and Gram‐positive bacteria.