| Abstract | Istražen je utjecaj sastojaka eteričnih ulja (karvakrol, eugenol, heksenal, timol i terc–
butilhidrokinon) na odabrane bakterije roda Salmonella: S. agona, S. enteritidis, S. infantis i S.
paratyphi te vrste Escherichia coli i Enterococcus faecalis. Minimalna bakteriocidna
koncentracija sastojaka eteričnih ulja određena je makrodilucijskom metodom. Istom metodom
je utvrđen sinergistički utjecaj kombinacija sastojaka eteričnih ulja. Istražena je promjena broja
stanica odabranih bakterija tijekom inkubacije u moždano – srčanom bujonu uz dodatak
sastojaka eteričnih ulja nakon 1., 2., 4., 8. i 24. sata uzgoja pri 37°C. Metodom dilucije je
istražena promjena broja stanica odabranih bakterija tijekom inkubacije u mljevenom svinjskom
mesu s dodatkom različitih koncentracija odabranih sinergističkih kombinacija sastojaka
eteričnih ulja nakon 1., 4., 8. i 24 sata inkubacije na 37°C. Određen je kemijski sastav i senzorske
promjene prije, tijekom i nakon kuhanja mljevenog mesa sa sinergističkim kombinacijama
sastojaka eteričnih ulja.
Najmanja minimalna bakteriocidna koncentracija primijećena je pri 31,25 mgL-1 timola
prema S. enteritidis i E. coli dok je terc – butilhidrokinon u potpunosti inhibirao S. paratyphi tek
pri 250 mgL-1. Utvrđena je statistički značajna razlika tijekom inkubacije S. infantis sa
sinergističkom kombinacijom od 25 mgL-1 karvakrola i 12,5 mgL-1 heksenala i 18,75 mgL-1
karvakrola i 18,75 mgL-1 terc–butilhidrokinona i E. faecalis s kombinacijom 12,5 mgL-1 terc–
butilhidrokinona i 37,5 mgL-1 timola. Inkubacijom pojedinačnih tvari u moždano – srčanom
bujonu: eugenola, karvakrola i timola na S. agona; karvakrola i terc–butilhidrokinona na S.
infantis; karvakrola i timola na S. paratyphi te terc-butilhidrokinona i timola na Enterococcus
faecalis utvrđena je statistički značajna razlika. Tijekom inkubacije S. enteritidis i E. coli nije
utvrđena statistički značajna razlika. Statistički značajna razlika nije utvrđena tijekom inkubacije
odabranih kultura u mljevenom mesu, kao niti senzorske promjene u mljevenom svinjskom mesu
prije kuhanja, tijekom i nakon kuhanja. |
| Parallel abstract (English) | Synergistic effect of essential oil constituents (eugenol, carvacrol, thymol, hexenal and
tert–butylhydroquinone) on selected bacteria of genera Salmonella: S. agona, S. enteritidis, S.
infantis and S. paratyphi as well as bacterial species Escherichia coli and Enterococcus faecalis
was investigated. Minimal bactericidal concentration of essential oil constituents was determined
by macrobroth dilution method. The same method was used to determine synergistic effect of
combination of essential oil constituents. Changes of viable cells during incubation with eugenol,
carvacrol, thymol, hexenal and tert–butylhydroquinone, in Brain Heart Infusion broth in 1st, 2nd,
4th, 8th and 24th hour at 37°C, was essayed,. By dilution method, changes of viable cells of
tested bacteria during incubation in minced pork meat with different synergistic combinations of
essential oils were analysed in 1st, 4th, 8th and 24th hour of incubation at 37°C. Chemical
composition as well as sensory changes in meat with synergistic combinations of essential oil
constituents was determined before, during and after cooking meat.
Thymol was most powerful against S. enteritidis and E. coli with minimal bactericidal
concentration of 31,25 mgL-1 while S. paratyphi was inhibited with 250 mgL-1 of tert–
butylhydroquinone. Statistically significant difference during incubation of S. infantis with
synergistic combinations with 25 mgL-1 of carvacrol and 12,5 mgL-1 hexenal and 18,75 mgL-1 of
carvacrol and 18,75 mgL-1 tert–butylhydroqinone and E. faecalis with combination of 12,5 mgL-
1 tert – butylhydroqinone and 37,5 mgL-1 thymol was observed. During incubation of individual
essential oil constituents in Brain Heart Infusion broth, statistically significant difference was
observed with: eugenol, carvacrol and thymol on S. agona; carvacrol and tert –
butylhydroquinon on S. infantis; carvacrol and thymol on S. paratyphi and tert–
butylhydroquinone and thymol against Enterococcus faecalis. During incubation of individual
essential oil constituents with S. enteritidis i E. coli no statistically difference was detected.
No statistical difference was noticed during incubation of selected bacterial cultures in
minced pork meat with synergistic combinations of essential oil constituents in different
concentrations as well as sensory difference of uncooked meat and meat during and after
cooking. |
