doctoral thesis
Synergistic effect of essential oil constituents on selected Salmonella

Hrvoje Pavlović (2006)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food and Nutrition Research
Sub-department of Biology and Microbiology
Metadata
TitleSinergistički učinak sastojaka eteričnih ulja na odabrane bakterije roda Salmonella
AuthorHrvoje Pavlović
Mentor(s)Tomislav Klapec
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.
Keywordsbacteria Salmonella Enterococcus faecalis Escherichia coli synergistic effect
Parallel title (English)Synergistic effect of essential oil constituents on selected Salmonella
Committee MembersFrane Delaš (committee chairperson)
Tomislav Klapec (committee member)
Zlata Milaković (committee member)
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food and Nutrition Research
Sub-department of Biology and Microbiology
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Food Microbiology
UDK578/579
NATURAL SCIENCES
Virology. Microbiology
Study programme typeuniversity
Study levelpostgraduate
Study programmeFood Engineering
Academic title abbreviationdr. sc.
Genredoctoral thesis
Language Croatian
Defense date2006-12-20
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.
Parallel keywords (Croatian)bakterije Salmonella Enterococcus faecalis Escherichia coli sinergistički učinak
Extent111 str. ; 30 cm
Versionaccepted version
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
Noteaccepted version
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:643826
CommitterIvana Šuvak