This masters thesis deals of microbial contamination of chicken eggs in storage. Test samples were tracked for the following microbial indicators: Total Viable Count (TVC), bacteria of the Enterobacteriaceae family, bacteria of the Enterococcus genus, psychrotrophic microorganisms, yeasts and molds. Microbial analysis was made for eggs acquired from market chains, originating from three different farming environments: enriched cages, cage-free and free range. Samples were stored in three different temperature environments: refrigerated at 5 °C for the whole storage period, stored in a thermostated box at 28 °C for the whole storage period and alternating between 5 °C and 28 °C temperature environments with one week storage periods each. The analysis of acquired test samples shows that TVC did not change significantly between different farming environments and storage temperature environments. Cage-free eggs show increasing TVC in long time storage (21 days). Cage-free and free range eggs also show higher count for Enterobacteriaceae. Enterobacteriaceae counts show significant differences between samples stored at constant 28 °C and alternating temperatures. Lowest microorganism count for bacteria of the Enterobacteriaceae family was observed at alternating temperatures. Long time storage resulted in elevated Enterobacteriaceae count in cage-free eggs. Presence of Enterococcus, psychotrophic microorganism and molds was detected in a low number of samples.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:250792 |
| Date | January 2015 |
| Creators | Zemanová, Aneta |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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