Food sensory properties, analyses and chemical composition are very important because they provide information about product quality and end-user acceptance or preferences. An assessment of sensory ...characteristics and chemical composition of mountain sheep and cow’s-milk cheese from shepherd’s huts and industrial manufacturers in Kosovo was carried out. Consumer-oriented tests using a 9 point hedonic scale were conducted in order to determine Sharri cheese acceptability. Chemical parameters (fat content, fat content of dry matter, acidity, protein, dry matter, mineral and water content and sodium chloride content) of 45-day brine cheese samples were also analyzed. Chemical and sensory assessment demonstrated large property differences. A recommendation stems from the results showing that the standardization of both artisanal and industrial production of Sharri cheese is required.
The aim of this study is to identify and characterise potential autochthonous functional starter cultures in homemade horsemeat sausage. The dominant microflora in the samples of horsemeat sausage ...were lactic acid bacteria (LAB), followed by micrococci. Among the LAB,
ssp.
and
were the dominant species, and since the first is not common in fermented sausages, we characterised it as a potential functional starter culture.
ssp.
produced a significant amount of lactic acid, displayed good growth capability at 12, 18 and 22 °C, growth in the presence of 5% NaCl, good viability after lyophilisation and in simulated gastric and small intestinal juice, antimicrobial activity against test pathogens, and good adhesive properties
.
Growth Inhibition of Aspergillus Ochraceus ZMPBF 318 and Penicillium Expansum ZMPBF 565 by Four Essential Oils Čvek, Domagoj (Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia); Markov, Ksenija (Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia); Frece, Jadranka (Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia) ...
Arhiv za higijenu rada i toksikologiju,
06/2010, Volume:
61, Issue:
2
Journal Article
Peer reviewed
Open access
Fungi produce a large variety of extracellular proteins, organic acids, and other metabolites and can adapt to several environmental conditions. Mycotoxin-producing moulds of the genera Aspergillus ...and Penicillium are common food contaminants. One of the natural ways to protect food from mould contamination is to use essential oils. In this study, we evaluated the effect of essential oils of cinnamon, lavender, rosemary, and sage at 1 % (v/v) concentration in yeast media inoculated with spores (final concentration 10 6 mL -1 media) of Aspergillus ochraceus ZMPBF 318 and Penicillium expansum ZMPBF 565, alone or in combination, on fungal biomass. Cinnamon showed the best inhibitory effect (100 %). Lavender oil best inhibited the growth of Aspergillus ochraceus (nearly 100 %), and was less successful with Penicillium expansum (having dropped to 57 % on day 28). With cultivation time the inhibitory effect of sage and rosemary oil grew for Aspergillus ochraceus and dropped for Penicillium expansum.These results suggest that fungi can be controlled with essential oils, especially with cinnamon oil.
Plijesni su poznate po svojoj visokoj sposobnosti proizvodnje razli _itih izvanstani _nih proteina, organskih kiselina i drugih metabolita i po svojoj mogućnosti prilagodbe na nepovoljne okolišne uvjete, a primjenjuju se i u obradi otpadnih voda. Plijesni iz rodova Aspergillus i Penicillium _esti su kontaminanti u hrani i posebno opasne jer tvore toksi _ne metabolite mikotoksine. Eteri _na ulja mogu se primijeniti kao prirodna sredstva za zaštitu hrane od kontaminacije plijesnima. U radu su prikazani rezultati istraživanja utjecaja eteri _nih ulja cimeta, lavande, ružmarina i kadulje na kontrolu rasta biomase plijesni Aspergillus ochraceus ZMPBF 318 i Penicillium expansum ZMPBF 565, u obliku _istih i miješanih kultura. Ulja su dodavana u koncentraciji od 1 % (v/v), a podloga (kvaš _ev ekstrakt) bila je nacijepljena suspenzijama spora plijesni (10 6 mL -1 podloge). Eteri _no ulje cimeta pokazalo je najveći inhibitorni u _inak (100 %). Inhibitorni u _inak eteri _nog ulja lavande bio je veći na rast Aspergillusa ochraceusa (skoro 100 %) nego Penicilliuma expansuma (57 %). Eteri _na ulja kadulje i ružmarina pokazala su suprotne u _inke. Inhibitorni u _inak na Aspergillus ochraceus tijekom perioda uzgoja je rastao, a na Penicillium expansum opadao.Rezultati pokazuju da se rast plijesni može kontrolirati primjenom eteri _nih ulja, a posebno uljem cimeta. Također upućuju na ekonomsku vrijednost takvih tretmana.
The microbiological quality of a hard mountain unpasteurised sheep cheese from three randomly selected manufacturing locations in Kosovo was investigated. Forty‐eight samples of row milk, coagulum, ...8–10 days ripening cheese and of ready to eat cheese (45‐days in brine) were tested. Seventy‐five per cent of raw milk samples failed to comply with EU regulation 853/2004. All of coagulum and ripened cheese failed to comply with EU regulation 2073/2005 on process hygiene criteria. Despite the high incidence of coagulase‐positive staphylococci even in the final product >10⁵ colony‐forming units (cfu)/g, Staphylococcal enterotoxin was detected in none of the samples and no samples were positive for Listeria monocytogenes and Salmonella enteritidis.
Fungicides are the most common agents used in postharvest treatment of fruit and are the most effective against blue mould, primarily caused by Penicillium expansum. Alternatively, blue mould can be ...treated with antagonistic microorganisms naturally occurring on fruit, such as the bacterium Gluconobacter oxydans. The aim of this study was to establish the antifungal potential of the G. oxydans 1J strain isolated from apple surface against Penicillium expansum in culture and apple juice and to compare it with the efficiency of a reference strain G. oxydans ATCC 621H. The highest antifungal activity of G. oxydans 1J was observed between days 3 and 9 with no colony growth, while on day 12, P. expansum colony diameter was reduced to 42.3 % of the control diameter. Although G. oxydans 1J did not fully inhibit mould growth, it showed a high level of efficiency and completely prevented patulin accumulation in apple juice.
Tretiranje voća fungicidima, nakon berbe, uobičajeni je način suzbijanja plave plijesni. Međutim, propadanje voća može se spriječiti i upotrebom antagonističkih mikroorganizama, kao što je bakterija Gluconobacter oxydans. Svrha ovoga rada bila je izolirati prirodnu mikrobnu populaciju s površine jabuka i istražiti moguće inhibitorno djelovanje Gluconobacter oxydans 1J na plavu plijesan, Penicillium expansum, najvažnijeg uzročnika kvarenja jabuka u skladištu. Najveća antifungalna aktivnost bakterije primijećena je između 3. i 9. dana, kada nije zabilježen porast kolonija, a nakon 12. dana promjer kolonije plijesni bio je manji za 42,3 %. Iako istraživana bakterija Gluconobacter oxydans 1J nije u potpunosti inhibirala rast plijesni u jabučnom soku pokazala je visoku razinu učinkovitosti (od 86 % do 95 %). Gluconobacter oxydans 1J djelomično inhibira rast plijesni i u potpunosti biosintezu patulina, ovisno o vremenu i uvjetima uzgoja.
The nephrotoxic mycotoxin ochratoxin A (OTA), a common contaminant of cereals, has been implicated in the etiology of endemic nephropathy. It was also frequently found in low concentrations in blood ...of healthy populations in countries where endemic nephropathy is not known. However, data on regional and seasonal differences in the frequency and concentration of OTA in human blood are scarce. In June, September and December 1997, and March 1998, about 50 human blood samples were collected randomly from blood donors for blood banks in the Coatian cities of Osijek, Rijeka, Split, VaraZdin and Zagreb. OTA was measured in the total of 983 samples using an HPLC technique with fluorescent detection. The daily intake of OTA was estimated from the mean concentration found in different cities and at different times of year. Samples containing OTA above the detection limit (0.2 ng/ml of plasma) were found in populations from all Croatian cities at all collecting periods. The highest frequency (59%) of samples containing OTA above the detection limit and the highest mean concentration (0.39 ng/ml) were found in June. Both the frequency and the mean concentration were lowest in all samples in December (36% and 0.19 ng OTA/ml, respectively). Osijek was the city with the highest frequency of OTA-positive samples (81%) and the highest mean OTA concentration (0.56 ng/ml). The total mean concentration of OTA in blood of healthy population in Croatia is lower (0.30 ng/ ml) than the mean concentration in European countries as a whole (0.90 ng/ml). The estimated daily intake, calculated from the mean concentration in all blood samples, is 0.40 ng OTA/kg body weight, which is much lower than that proposed by World Health Organization as the tolerable daily intake (16.0 ng/kg body weight). Healthy populations of Croatia are exposed to low, but seasonally and regionally variable amounts of OTA.
The aim of this study was to determine the effects of the essential oil of Thymus serpyllum L. and of its components thymol and total phenols (total phenolic content, TPC) extracted from the plant on ...the growth and mycotoxin production of Aspergillus ochraceus, A. carbonarius, and A. niger. Minimal inhibitory concentration (MIC) determined for the essential oil and thymol, and selected concentration of the TPC extract inhibited fungal growth and ochratoxin A biosynthesis by more than 60 %, depending on the conditions and duration of incubation with the fungi. Essential oil showed the strongest inhibitory effect which may have been related to the synergistic or cumulative effects of its components.
Conventional methods for the identification of Listeria in foodstuffs are generally cumbersome and time consuming. The use of primary enrichment in half strength Fraser broth and the use of PALCAM ...agar were assessed in comparison with API Listeria and polymerase chain reaction (PCR) for their ability to accurately detect and confirm the presence of List. monocytogenes in milk products. The aim of our work was to detect List. monocytogenes in domestic unpasteurised milk, fresh cheese and cream of raw milk taken from four different district of Zagreb-Croatia using conventional (microbiological and biochemical – API test) and PCR methods. Of the 180 milk products samples tested, 27·6% were presumptively positive for Listeria on PALCAM agar. Only 21·3% of samples were confirmed to be positive for Listeria by API Listeria test, and 17·3% were confirmed to be positive for List. monocytogenes by PCR amplification of the hly gene (64 bp). PCR was able to eliminate the false positive and detect all List. monocytogenes in the milk products, unlike the conventional methods used in the industry. These results indicate a low presence of this pathogen in this area (Zagreb) of Croatia. PCR proves to be a sensitive and rapid technique to be included in the procedure of detection of List. monocytogenes in food products and this method is considerably faster than current standard methods.
Detailed investigation on the effect of gamma (γ) irradiation on germination, sporulation, and growth of aflatoxigenic moulds (Aspergillus parasiticus 2999, Aspergillus flavus 305, and Aspergillus ...niger 388), as well as on the reduction of aflatoxin B1 (AFB1) level in artificially and naturally contaminated maize/feed samples was performed. The results of in vitro and in situ experiments with aflatoxigenic moulds demonstrated that 5 kGy-γ irradiation manages to prevent sporulation, germination and growth of the tested moulds both when in form of a pure and when in form of a mixed culture. In the feed samples artificially contaminated with AFB1 (50 μg kg−1) 5 kGy-γ irradiation reduced AFB1 level by around 60%, while 10 kGy-dose reduce it for around 85%. Similarly, in feed samples spiked with AFB1 in the concentrations of 100 μg kg−1 5 kGy-dose reduced the AFB1 level by approximately 70%, while the dose of 10 kGy reduced it by approximately 90%. The experiments on naturally contaminated maize samples (n = 30) confirmed these observations; following a 5 kGy-irradiation, the overall mean AFB1 reduction equalled to 69.8%, while the irradiation with a 10 kGy-dose achieved the overall mean toxin reduction of 94.5%. The obtained results indicate that γ irradiation can be used to prevent the growth of aflatoxigenic moulds and to reduce the AFB1 levels in various goods intended for animal and human consumption, thus minimizing the animal and human exposure to this carcinogenic mycotoxin.
•Effect of gamma irradiation on aflatoxigenic moulds AFB1 level was tested.•Gamma irradiation effectively stopped moulds' germination, sporulation and growth.•Level of AFB1 in maize and feed samples was reduced by gamma irradiation.•Gamma irradiation can be used to control AFB1 level in various commodities.
This study has been undertaken with the aim of elucidating the effect of a fat-free diet (FFD), which is known to be deficient in essential fatty acids (EFA), on the composition of fatty acids in the ...brain and liver glycerophospholipids of rats. Changes in the stereochemical distribution of fatty acids linked to the sn-1 or sn-2 position were of special interest. Two groups of animals were fed either the control diet (CD) or the FFD for two weeks. From the total lipid extracts of the brain and liver tissues, phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol+phosphatidylserine (PI+PS) fractions were separated by column and thin layer chromatography (TLC). After digestion with phospholipase A2 (PLA2), fatty acids from the sn-1 and sn-2 positions were separately converted into methyl esters and analyzed by gas chromatography. In animals fed FFD, the relative levels of unsaturated fatty acids increased in the sn-1 position of the PI+PS fraction in both liver and brain tissues, as well as in the PE fraction from the brain tissue. In other fractions no statistically significant differences were found. When the levels of particular fatty acids were evaluated, significant decreases in the amounts of palmitic (PA, 16:0), stearic (SA, 18:0), and nervonic (NA, 24:1n-9) acids, and/or significant increases of eicosenoic (ENA, 20:1n-9), arachidonic (AA, 20:4n-6) and docosahexaenoic (DHA, 22:6n-3) acids were detected in some fractions. It can be concluded that in the brain and liver glycerophospholipids of rats fed FFD, the EFAs lacking in the diet were moderately substituted by endogenously synthesized unsaturated fatty acids.
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