28 research outputs found
Fate of Fusarium mycotoxins during the production process of bakery products
Producing safe food is a goal and an obligation for each producer. Mycotoxins by representing the most significant
contaminants of grain are considered to be the main risk in the production of safe bakery products. Conditions during the
production process defined by temperature regime, duration of the temperature regime, moisture content, pH value, as well
as the type and level of mycotoxin concentration in the matrix are the most important factors influencing the reduction of
mycotoxin content. The aim of this study was to examine the influence of production process of different types of bread, rusk,
bread crumbs and biscuits on the content of deoxynivalenol, zearalenone and total fumonisins in bakery products. Samples of
naturally contaminated whole grain wheat flour (DON 700 μg/kg), wheat flour type T-1100 (DON 500 μg/kg) and whole kernel
corn flour (DON 2420 μg/kg, ZON 292 μg/kg and Total FUMO 554 μg/kg) were used to examine the influence of the production
process on the content of Fusarium mycotoxins in bakery products. Experimental production of different types of bread, rusk,
bread crumbs and biscuits was conducted in a bakery pilot plant. Ridascreen® ELISA-assay was used to analyze the content of
deoxynivalenol, zearalenone and total fumonisins. Based on the results it was concluded that the process of production of
bread, rusk, bread crumbs and biscuits significantly reduces the content of deoxynivalenol, zearalenone and total fumonisins
in final products (p<0,05). However, in some cases (rusk and bread crumbs) results raised a question if the % of reduction is
high enough to make the final product compliant to European legislation (Reg. 1881/2006). Although European Food Safety
Authority and the European Commission had frequently expressed opinions on Fusarium toxins, setting limits, regulations and
guidelines in order to reduce their levels in raw materials and food commodities: maximum limits for mycotoxins set by
European legislation (Reg. 1881/2006) apply to content in 'product as is' regardless the huge difference in moisture content in
various products grouped in same category
Effect of water activity on the radial growth of fungi isolated from dry-cured sheep ham, in vitro (Serbia)
In the Western Balkans, traditional dry-cured sheep ham called Pastrma or Stelja is produced. Dry-cured sheep ham from Sjenica is produced in a very complex manner, and a prerequisite for its production is the sanitary safety of raw materials in accordance with veterinary and sanitary regulations. Isolation and preliminary identification of fungi from sheep ham were carried out in this study, as well as in vitro testing of the effects of water activity (aw) on the growth of isolated fungi. Fungi were isolated from 9 samples of dry-cured sheep meat taken from three households in the area of Sjenica in two productive years (2015 and 2016). Species of genus Penicillium were isolated as dominant in all the investigated samples. Water activity was tested on MY50GF agar from the series of malt extract yeast extract glucose fructose agar. Water activity was set to values of 0.87, 0.89, and 0.97. The results of the research showed that the growth of fungal colonies is under the direct influence of water activity. Fungi grew fastest at water activity of 0.97, and the highest growth of all tested species was recorded after 3 (A. niger), 7 (P. patulum), and 10 days (A. nidulans).Publishe
Enterobacteriaceae in food safety with an emphasis on raw milk and meat
There has been a growing interest in traditional dairy (such as raw milk cheeses) and meat products, in recent years. However, these products are suitable and nutrient medium and may be easily contaminated by microorganisms such as Enterobacteriaceae. Enterobacteriaceae are considered to be the indicator bacteria for microbiological quality of food and hygiene status of a production process. Additionally, the food contaminated by Enterobacteriaceae poses a microbiological risk for consumers. In fact, the contamination of raw milk and meat by Enterobacteriaceae amid manufacturing may easily occur from various environmental sources, and this group of bacteria is frequently detected in dairy and meat products. Therefore, monitoring the microbiological quality of the used raw material and maintaining high standards of hygiene in the production process are mandatory for a high quality of traditional products and the safety of the potential consumers. The goal of this review is to present the most recent survey on Enterobacteriaceae growth, number, and distribution in raw milk cheeses and meat, as well as to discuss the sources of contamination and methods of control.Accepted for publishin
The potential for sustainable bioethanol production in Serbia: available biomass and new production approaches
Bioethanol has become one of the most promising biofuels today in response to uncertain fuel supplies and efforts to
reduce greenhouse gas emissions. The biofuels are easily available from common biomass sources, biodegradable and
contribute to sustainability. In Serbia, the industrial production of bioethanol still relies on conventional energy crops
containing starch and sugar such as corn, wheat and triticale, which are the most suitable and available agricultural raw
materials. The preview of bioethanol production possibilities and available feedstocks in Serbia are presented in this study.
Several production approaches based on crop selection, process integration and waste utilization were also considered in
order to increase production efficiency and to avoid the competition of the feedstock utilization for food and energy.
Utilization of corn, wheat and triticale (plant resistant to severe climate and soil conditions) were investigated for
bioethanol production as well as utilization of damaged crops (e.g. wheat) that are not appropriate for food consumption.
Also, utilization of the stillage for the production of lactic acid could also improve the bioethanol production. The
economy of bioethanol production was analyzed in order to decrease the production costs and make this biofuel
competitive with fossil fuels. The analysis has compared the cost of bioethanol produced from three crops that can be
cultivated in Serbia: corn, wheat, and triticale, and the triticale has shown as the most favourable
КАРАКТЕРИЗАЦИЈА КОАГУЛАЗА НЕГАТИВНИХ СТАФИЛОКОКА ИЗОЛОВАНИХ ИЗ СУВОГ МЕСА ОВЧИЈЕГ ТРУПА – СЈЕНИЧКА ОВЧИЈА СТЕЉА
Sheep prosciutto is a fermented meat product for whose quality and organoleptic
properties are increased by microorganisms making it a high quality product.
Fermentation process of sheep prosciutto is not controlled, therefore in this case,
the isolated strains that make up the microbiota are wild (occur in nature).
Coagulase-negative staphylococci (CNS) have an important role in defining the
characteristics of this product. The aim of our work was: to isolate coagulasenegative
staphylococci from sheep prosciutto, as well as characterisation of the
isolated staphylococci (CNS) to precisely define and determine the dominating strain
of coagulase-negative staphylococci in sheep prosciutto and how it affects the quality
of the product.
Materials for this research consisted of 9 samples taken from three households in
Sjenica during two production years (2014 and 2015 yr.). Phenotyping of the isolates
was performed by Gram staining and catalase test, and then the isolates were
subjected to the coagulase test. In order to identify the isolates the following tests
were performed: The ability of bacterial colonies to induce hemolysis on blood agar,
mannitol fermentation, growth at different temperatures (150C and 450C), tolerance
to novobiocin, lipolytic activity, proteolytic activity and synthesis of EPS
(Exopolysaccharides).
Based on the results, a preliminary identification of 71 isolates of coagulasenegative
staphylococci from Sjenica sheep prosciutto as Staphylococcus epidermidis,
Staphylococcus saprophyticus, Staphylococcus xylosus and Staphylococcus carnosus
was made.Publishe
Advantages and disadvantages of non-starter lactic acid bacteria from traditional fermented foods: potential use as starters or probiotics
Research Areas: Food Science & TechnologyTraditional fermented foods are a significant source of starter and/or non-starter lactic acid bacteria (nsLAB). Moreover, these microorganisms are also known for their role as probiotics. The potential of nsLAB is huge; however, there are still challenges to be overcome with respect to characterization and application. In the present review, the most important steps that autochthonous lactic acid bacteria isolated from fermented foods need to overcome, to qualify as novel starter cultures, or as probiotics, in food technology and biotechnology, are considered. These different characterization steps include precise identification, detection of health-promoting properties, and safety evaluation. Each of these features is strain specific and needs to be accurately determined. This review highlights the advantages and disadvantages of nsLAB, isolated from traditional fermented foods, discussing safety aspects and sensory impact.info:eu-repo/semantics/publishedVersio
Lactobacillus curvatus from fermented sausages as new probiotic functional foods
This research examined in vitro probiotic potential of Lactobacillus curvatus isolates from fermented sausage originating in Southeast Serbia which was prepared using traditional production techniques. Strains of L. curvatus were isolated and identified at the level of species using API 50CHL sets and 16s rDNA sequencing, after which their probiotic potential was measured.
The research consisted of the examination of isolate survival rates in the gastrointestinal tract, synthesis of biogenic amines, the growth on the media with different quantities of phenol, antibiotic resistance test, and antimicrobial activity against clinical strains of Pseudomonas spp., Proteus spp., Enterobacter spp., Escherichia coli and Listeria monocytogenes. The examined isolates have shown a good survival rate at low pH in the simulated stomach and small intestine conditions. Synthesis of biogenic amines was exhibited by the isolate sk1-10, which had a positive reaction to histidine. Analyzed isolates grew well on media with 0.1%
and 0.2% of phenol, L.curvatus sk1-8 and sk5-2 have grown in media with 0.3% phenol. All tested isolates have exhibited high sensitivity to most analyzed antibiotics (tetracycline, amoxicillin, ceftriaxone, erythromycin, penicillin), resistance to ofloxacin, and cephalexin isolates sk4-3a and sk4-15. The examined isolates have shown a broad inhibitory spectrum against pathogens.Publishe
Mogućnosti upotrebe džibre iz proizvodnje bioetanola na različitim supstratima
Stillage is a main by-product of the bioethanol industry and, depending on the
origin of substrates for bioethanol production, it can be a significant pollutant
affecting the profitability of bioethanol production. Directing the stillage towards
the production of bio-based chemicals or high-quality feed is a preferred stra-
tegy. In this paper, a complete utilization of stillages of different origins was
assessed. Thin stillages from bioethanol production from molasses, wasted
bread and corn were chemically characterized, evaluated and compared as
substrates for lactic acid (LA) and probiotic biomass production by Lactobacil-
lus rhamnosus ATCC 7469, while solid fractions of wasted bread and corn stil-
lages were analyzed for feed. The impact of pH control using CaCO 3 or NaOH
was also examined, both in terms of LA production and valorization of the
remains generated in each process.A maximal LA productivity of 1.14 g/(L h)
was obtained on thin wasted bread stillage with pH control by NaOH while the
number of viable probiotic bacterial cells was above 109 CFU/mL. The com-
position of the solid fraction of the wasted bread stillage was complementary
with the needs of monogastric animals, while the solid fraction of corn stillage
was more adequate for the nutritional requirements of ruminants.Džibra je najznačajniji otpadni ili sporedni proizvod industrije bioetanola. U zavisnosti od
porekla supstrata koji se koriste u proizvodnji bioetanola, može biti značajan zagađivač,
pa utiče na profitabilnost proizvodnje bioetanola. Upotreba džibre u biotehnološkim
postupcima proizvodnje hemikalija ili visoko vredne stočne hrane je poželjna strategija
za smanjenje negativnih efekata džibre na životnu sredinu i profitabilnost proizvodn je
bioetanola. U ovom radu je analizirana mogućnost kompletnog iskorišćenja džibre.
Tečne džibre iz proizvodnje bioetanola na melasi, otpadnom hlebu i kukuruzu su
hemijski okarakterisane i upoređene kao supstrati za proizvodnju mlečne kiseline (MK) i
probiotske biomase soja Lactobacillus rhamnosus ATCC 7469, dok je čvrsti ostatak
hlebne i kukuruzne džibre analiziran kao hrana za životinje. Takođe je ispitan uticaj pH
kontrole pomoću CaCO3 ili NaOH sa aspekta proizvodnje MK i sa aspekta iskorišćenja
ostataka iz oba procesa. Maksimalna produktivnost MK od 1,14 g/(L h) je dobijena na
tečnoj džibri iz otpadnog hleba sa pH kontorolom pomoću NaOH, dok je broj živih pro-
biotskih bakterija bio preko 10 9 CFU/mL. Rezultati su pokazali da je sastav čvrste frak-
cije otpadne hlebne džibre komplementaran sa potrebama monogastričnih životinja, dok
sastav čvrste frakcije kukuruzne džibre više odgovara nutritivnim potrebama preživara
Quality and autochthonous microbiota of dry-cured sheep ham from western Balkans
Dry-cured sheep ham is a traditional product of Western Balkans. It is prepared by dry curing specially treated whole sheep carcasses which are smoked for a short time and spontaneously fermented in air under uncontrolled conditions. Lactic acid bacteria (LAB) play a key role in defining the quality and organoleptic characteristics of dry-cured sheep ham. The aim of this research was to investigate the chemical parameters of drycured sheep ham quality as well as the isolation and preliminary categorization of LAB. To this end, samples of dry-cured sheep ham were obtained from nine sheep of average age of about five years, from three households from the geographical area Sjenica (Western Serbia). Physicochemical analysis has determined the content of water, protein, fat, mineral matter, water activity and pH values in the product. Phenotypic characterization of LAB isolated from dry-cured sheep ham was based on the general morphology of the cell, physiological tests and sugar fermentation patterns of LAB isolates. 124 isolates of LAB were preliminary identified as Lactobacillus curvatus , Lactobacillus sakei and Enterococcus faecium . Chemical analysis confirmed a harmonious relationship between the quality parameters of dry-cured sheep ham.Publishe
Serbian traditional goat cheese : physico-chemical, sensory, hygienic and safety characteristics
Research Areas: MicrobiologyThis research project aimed to investigate the physico-chemical, sensory, hygienic and safety characteristics of raw goat milk, whey, brine and traditional goat cheese during the ripening period of 28 days. Physico-chemical parameters included the determination of dry matter, fat, ash, protein, pH, water activity and NaCl content. The presence of Enterobacteriaceae and fungi was estimated on milk and cheese samples, and a sensory panel evaluated the products’ features and acceptability during ripening. The results show that the cheese under study belongs to the acid full-fat cheese group. A consumer panel attributed high scores to the goat cheese, until the 21st day of ripening. After this period, the overall features altered significantly, including augmented bitterness, odor intensification and the development of molds on the surface. The presence of fungi, associated with Enterobacteriaceae, suggests that the hygiene of the production processes needs to be improved. Regarding microbial safety, the detection of putative pathogens and antibiotic resistances recommend an active surveillance of traditional foods to avoid foodborne infections and/or the dissemination of resistant microorganisms along the food chaininfo:eu-repo/semantics/publishedVersio