Usporedba mikrobioloških pokazatelja kvalitete i sigurnosti kulena proizvedenog u kontroliranim i nekontroliranim uvjetima

master's thesis

• Title (english): Microbiological Indicators of Safety and Quality of Dry Fermented Sausage Kulen Produced under Controlled and Uncontrolled Conditions
• Author: Dunja Igrec
• Mentor: Nevijo Zdolec (mentor)
• Committee member: Vesna Dobranić (predsjednik povjerenstva)
• Committee member: Željka Cvrtila (član povjerenstva)
• Committee member: Nevijo Zdolec (član povjerenstva)
• Granter: University of Zagreb; Faculty of Veterinary Medicine; (Department of Hygiene and Technology of Foodstuffs); Zagreb
• Defense date and country: 2020-11-20, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Veterinary Medicine; Veterinary Public Health and Food Safety

Abstract

Cilj ovog rada bila je odrediti mikrobiološke pokazatelje sigurnosti i kakvoće kulena
proizvedenih u nekontroliranim (n=9) i kontroliranim uvjetima (n=8). Određivan je broj
bakterija mliječne kiseline i enterokoka kulturelnim metodama te prisutnost bakterije Listeria
monocytogenes molekularnim postupkom (LAMP, Molecular Detection System), ispitana
osjetljivost izolata na antibiotike, te izvršeno organoleptičko ocjenjivanje proizvoda. Populacija
bakterija mliječne kiseline i enterokoka brojnija je u uzorcima kulena proizvedenih u
kontroliranim uvjetima. Primjenom MALDI-TOF masene spektrometrije determinirane su
vrste Pediococcus pentosaceus, Lactobacillus sakei i Lactobacillus curvatus koje su općenito
dominantne vrste u sastavu starter kultura u proizvodnji trajnih kobasica. U uzorcima kulena iz
nekontroliranih uvjeta proizvodnje dominantna populacija bakterija mliječne kiseline nije
izolirana, već su determinirane samo vrste Staphylococcus epidermidis, Staphylococcus
hominis, Staphylococcus warneri i Streptococcus vestibularis. Sojevi bakterija mliječne
kiseline bili su otporni na antibiotike, dok su sojevi stafilokoka najučestalije bili otporni na
eritromicin, penicilin, ampicilin i kanamicin. L. monocytogenes nije determinirana ni u jednom
uzorku kulena. Razlike u sastavu dominantne mikroflore moguć su razlog uočenih grešaka i
znakova kvarenja u uzorcima kulena iz nekontrolirane proizvodnje. Dobiveni rezultati ukazuju
na potrebu unaprjeđenja tradicionalne proizvodnje u smislu higijensko-tehnoloških normi kako
bi se održala autohtona svojstva ovog proizvoda.

Abstract (english)

The aim of this study was to determine microbiological indicators of safety and quality of kulen
produced in uncontrolled (n = 9) and controlled conditions (n = 8). The number of lactic acid
and enterococci was determined by culture methods and the presence of Listeria
monocytogenes by molecular tools (LAMP, Molecular Detection System), antimicrobial
susceptibility of isolates was tested and finally sensory analysis of products was performed.
The population of lactic acid bacteria and enterococci was higher in kulen samples produced
under controlled conditions. Using MALDI-TOF mass spectrometry, the species of
Pediococcus pentosaceus, Lactobacillus sakei and Lactobacillus curvatus were determined,
which generally are the dominant species in the composition of starter cultures in the production
of fermented sausages. In kulen samples made in uncontrolled production conditions, the
dominant population of lactic acid bacteria was not isolated, but only the species
Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus warneri and
Streptococcus vestibularis were confirmed. Lactic acid bacteria were susceptible to all
antibiotics, while staphylococcal strains were most frequently resistant to erythromycin,
penicillin, ampicillin, and kanamycin. L. monocytogenes was not determined in any of the kulen
samples. Differences in the composition of the dominant microflora may be the reason of
product failures and spoilage appearence of kulen from uncontrolled production. The obtained
results indicate the need for improvement of traditional production in terms of hygienic and
technological standards in order to maintain the indigenous properties of this autochthonous
product.

• Keywords: kulen; tradicionalna proizvodnja; industrijska proizvodnja; mikroflora; kvaliteta
• Keywords (english): kulen; traditional production; industrial production; microflora; quality
• Language: croatian
• URN:NBN: urn:nbn:hr:178:820644
• Study programme: Title: Veterinary Medicine; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: doktor/doktorica veterinarske medicine (doktor/doktorica veterinarske medicine)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-12-10 12:31:22