Antimicrobial properties of phenolic compounds from berries.
OBJECTIVE
To investigate the antimicrobial properties of phenolic compounds present in Finnish berries against probiotic bacteria and other intestinal bacteria, including pathogenic species.


RESULTS
Antimicrobial activity of pure phenolic compounds representing flavonoids and phenolic acids, and eight extracts from common Finnish berries, was measured against selected Gram-positive and Gram-negative bacterial species, including probiotic bacteria and the intestinal pathogen Salmonella. Antimicrobial activity was screened by an agar diffusion method and bacterial growth was measured in liquid culture as a more accurate assay. Myricetin inhibited the growth of all lactic acid bacteria derived from the human gastrointestinal tract flora but it did not affect the Salmonella strain. In general, berry extracts inhibited the growth of Gram-negative but not Gram-positive bacteria. These variations may reflect differences in cell surface structures between Gram-negative and Gram-positive bacteria. Cloudberry, raspberry and strawberry extracts were strong inhibitors of Salmonella. Sea buckthorn berry and blackcurrant showed the least activity against Gram-negative bacteria.


CONCLUSIONS
Different bacterial species exhibit different sensitivities towards phenolics.


CONCLUSIONS
These properties can be utilized in functional food development and in food preservative purposes.
Puupponen-Pimiä
R
R
VTT Biotechnology, PO Box 1500 (Tietotie 2), FIN-02044 VTT, Finland. riitta.puupponen-pimia@vtt.fi
Nohynek
L
L
Meier
C
C
Kähkönen
M
M
Heinonen
M
M
Hopia
A
A
Oksman-Caldentey
K M
KM
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000187:drug effects*; D005638:Fruit / Q000737:chemistry*; D007778:Lactobacillus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010636:Phenols