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In this study, moulds and mycotoxins presence in different tree nuts were investigated. The results showed that all of the 25 samples were contaminated with moulds. Mean values of total mould count varied from 1-4.9 cfu per grain. The most frequent species in hazelnut samples were Rhizopus oryzae (32.2%) and Aspergillus niger (28.9%). In walnuts A. niger (75.6%), in cashews also A. niger (42.4%) while in pistachio samples Alternaria alternata (20.7%), and Cladosporium cladosporioides (20.7%) were the most dominant. Rhizopus oligosporus was the only identified species in all almond samples (100%). Using Enzyme Linked Immunosorbent Assay (ELISA), the presence of total aflatoxins and ochratoxin A was examinated. In all analyzed samples, levels of ochratoxin A were below the limit of detection. Total aflatoxins were detected only in walnut samples with average concentration of 7.1 μg/kg.

Aromatic plants are one of the most important sources of biologically active secondary metabolites, which possess various antimicrobial characteristics. The aim of this work was to examine the effect of antifungal activities of mint and caraway essential oils against the selected fungi. Eight species of molds were selected for antifungal testing: Alternaria alternata, Aspegillus flavus, A. niger, A. versicolor, Eurotium herbariorum, Penicillium aurantiogriseum, P. chrysogenum and P. expansum. Testing of essential oils antifungal activity against the selected species was conducted using the disc diffusion method by adding mint and caraway essential oils (0.5, 1, 5, and 10 μl per disc). Antifungal activity of essential oils was expressed by the diameter of inhibition zone (mm). The most powerful effect of mint essential oil was recorded against E. herbariorum, as its growth was completely inhibited by the quantity of 5 μl. The weakest inhibitory effect was observed against P. chrysogenum (inhibition zone 13.67 mm) by the quantity of 10 μl. The most powerful antifungal activity of caraway was observed against E. herbariorum as growth was completely inhibited by the quantity of 10 μl. The weakest inhibitory effect was observed against A. niger (inhibition zone 28 mm) by the quantity of 10 μl. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 31029]

The growth of fungi on food causes physical and chemical changes which, further affect negatively the sensory and nutritive quality of food. Species from genera: Aspergillus, Penicillium, Fusarium, Alternariа, Cladosporium, Mucor, Rhizopus, Eurotium and Emericella are usually found. Some of them are potentially dangerous for humans and animals, due to possible synthesis and excretion of toxic secondary metabolites - mycotoxins into the food. Their toxic syndroms in animals and humans are known as mycotoxicoses. The pathologic changes can be observed in parenhimatic organs, and in bones and central nervous system also. Specific conditions are necessary for mycotoxin producing fungi to synthetize sufficient quantities of these compounds for demonstration of biologic effects. The main biochemical paths in the formation of mycotoxins include the polyketide (aflatoxins, sterigmatocystin, zearalenone, citrinine, patulin), terpenic (trichothecenes), aminoacid (glicotoxins, ergotamines, sporidesmin, malformin C), and carbonic acids path (rubratoxins). Aflatoxins are the most toxigenic metabolites of fungi, produced mostly by Aspergillus flavus and A. parasiticus species. Aflatoxins appear more frequently in food in the tropic and subtropic regions, while the food in Europe is more exposed to also very toxic ochratoxin A producing fungi (A. ochraceus and some Penicillium species). The agricultural products can be contaminated by fungi both before and after the harvest. The primary mycotoxicoses in humans are the result of direct intake of vegetable products contaminated by mycotoxins, while the secondary mycotoxicoses are caused by products of animal origin. The risk of the presence of fungi and mycotoxin in food is increasing, having in mind that some of them are highly thermoresistent, and the temperatures of usual food sterilization is not sufficient for their termination. The paper presents the review of most important mycotoxins, their biologic effects, the condition of their synthesis, occurence in food, permitted tolerant intake, as well as the possibility of their degradation. [Projekat Ministarstva nauke Republike Srbije, br. TR 31017]

The effect of water activity (aw) (0.85-0.97) on the growth of Aspergillus niger, A. flavus, Penicillium chrysogenum, P. brevicompactum and Eurotium herbariorum was examined. The growth of A. niger was lower than that of A. flavus at aw of 0.89 and 0.85. A. niger was the least tolerant of reduced moisture, and low aw (0.85) could prevent colony formation in 5 days. P. brevicompactum was less sensitive to reduced moisture conditions than P. chrysogenum. The maximal growth of E. herbariorum was observed at the level of 0.89 aw. Among the tested fungi, E. herbariorum appeared to be best adapted to the conditions of low aw. [Projekat Ministarstva nauke Republike Srbije, br. TR - 31017]

This study is concerned with the testing of antimicrobial activity of triticale stillage obtained after lactic fermentation by Lactobacillus fermentum PL-1. The antimicrobial tests were performed using the disc-diffusion and agar well diffusion methods. It was found that fermented triticale stillage after lactic acid fermentation exhibited an inhibitory effect towards tested Gram positive and Gram negative bacteria: Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis. The triticale stillage without addition of CaCO3 before fermentation showed a stronger antimicrobial effect in comparison with the triticale stillage with added CaCO3. Triticale stillage after lactic acid fermentation did not show any antifungal effect on the growth of tested moulds (Alternaria alternata, Aspergillus versicolor, Penicillium brevicompactum, and Fusarium subglutinans). [Projekat Ministarstva nauke Republike Srbije, br. TR-31017]

The effect of the oregano extract (Origanum vulgare L.) on the growth of Fusarium and Penicillium species isolated from cakes and ready-for-use fresh salads from different kinds of vegetables was investigated. Contents of the active component of extract were identified by GC-MS and they include: carvacrol (34.2%), carvone (18.5%), p-cimene (8.05%), thymol (3.74%). The oregano extract showed the ability to reduce mould growth at all applied concentrations. Stronger inhibitory effect on the growth of Penicillium species, contrary to Fusarium, was determined. At extract concentration of 2.5 mL/100 mL, growth of P. aurantiogriseum, P. glabrum and P. brevicompactum was completely inhibited during 14 days of incubation. At the same concentration, growth of Fusarium proliferatum was inhibited by 81.71%, F. oxysporum by 85.84%, F. verticillioides by 86.50%, P. chrysogenum by 86.2% and F. subglutinans by 88.85%.

Commercial extracts of three spices (lemon, caraway and basil) against Listeria monocytogenes, L. innocua and L. welshimeri were investigated using disc diffusion method. Lemon and basil extracts inhibited all the organisms at the level of ≥ 5 μl (lemon) and 20 μl (basil). These extracts produced inhibitory zones of 9-19 mm (lemon) and 8-11.5 mm (basil). The extract of caraway showed activity only against L. innocua at the highest level (20 μl), producing an inhibitory zone of 14.7 mm. Generally, the lemon extract was the most effective. This extract exhibited greater inhibitory activity against L. monocytogenes, while the basil extract had the strongest effect on L. welshimeri. [Projekat Ministarstva nauke Republike Srbije, br. TR 31017]

This study was aimed at investigating the antifungal potential of basil (Ocimmum basilicum L.) extract against toxin-producing Penicillium spp. (P. aurantiogriseum, P. glabrum, P. chrysogenum, and P. brevicompactum) isolated from food. The basil extract composition was determined by the GC-MS method. The major component identified in the extract was estragole (86.72%). The determination of the antifungal activity of basil extract on Penicillium spp. was performed using the agar plate method. Basil extract reduced the growth of Penicillium spp. at all applied concentration levels (0.16, 0.35, 0.70, and 1.50 mL/100mL) with the colony growth inhibition from 3.6 (for P. glabrum) to 100% (for P. chrysogenum). The highest sensitivity showed P. chrysogenum, where the growth was completely inhibited at the basil extract concentration of 1.50 mL/100mL. The growth of other Penicillium spp. was partially inhibited with the colony growth inhibition of 63.4 % (P. brevicompactum), 67.5% (P. aurantiogriseum), and 71.7% (P. glabrum). Higher concentrations (0.70 and 1.50 mL/100mL) reduced the growth of the aerial mycelium of all tested Penicillium species. In addition, at the same extract concentrations, the examination of microscopic preparation showed the deformation of hyphae with the frequent occurrence of fragmentations and thickenings, occurrence of irregular vesicle, frequently without metulae and phialides, enlarged metulae. The results obtained in this investigation point to the possibility of using basil extract for the antifungal food protection. [Projekat Ministarstva nauke Republike Srbije, br. TR-31017]

The paper presents the influence of oregano extract (Origanum vulgare L.) on growth of Aspergillus versicolor, Emericella nidulans, Eurotium herbariorum, E. amstelodami, E. chevalieri and E. rubrum - producers of sterigmatocystin (STC) isolated from salads. Antifungal tests were performed by agar plates method. The composition of the active component of extract was determined by GC-MS method and the major components were: carvacrol (34.20%), triacetin (22.91%), carvone (18.05%), p-cymene (8.05%) and thymol (3.74%). The examined extract showed the ability to reduce mold growth at all applied concentrations. Minimum inhibitory concentrations (MIC) for E. nidulans, E. chevalieri and E. amstelodami were 2.5% (v/v) and over 2.5% (v/v) for A. versicolor. At 1.5% (v/v) concentration the extract completely inhibited the growth of E. rubrum, whereas higher dose of 2.5% (v/v) was fungicidal against E. herbariorum. Besides its sensory role in food products, the examined oregano extract also exhibits antifungal activities against producers of STC.

In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA) and sterigmatocystin (STC). Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found in fresh salads were Cladosporium (42.89%), Penicillium (25.78%), Aspergillus (14.67%) and Alternaria (6.89%). C. cladosporioides (40.44%), followed by A. niger (10.22%), P. aurantiogriseum (7.55%), A. alternata (6.89%) and Fusarium spp. (3.11%) were the most dominating species. Other species were represented with 2.22% (Eurotium spp.), 1.56% (Botrytis spp.), 0.67% (Phoma spp.), 0.44% (Geotrichum spp., Mucor spp., Phialophora spp.) and 0.22% (Emericella spp., Paecilomyces spp., Trichoderma spp., Xeromyces spp.). Twenty-two of 41 identified mould species were potentially toxigenic, which accounted for 46.18% of the total isolated population. The most frequent were the potential producers of ochratoxin A (17.77%). Potential producers of moniliformin were isolated in 3.11% of samples, while producers of fumonisin and STC were found in 2.67% and 2.44% of samples, respectively. The tested isolates of OA producers did not demonstrate the ability to biosynthetise this mycotoxins, but two out of five isolates of A. versicolor were found to biosynthesise STC in doses of 109.2 ng mL-1 and 56.3 ng mL-1. The obtained results indicate that such products may threaten human health, considering that isolated species were potentially toxigenic, while isolates of A. versicolor also biosynthesised STS.

Listeria spp. are Gram positive, short, non-sporing rods, microaerophilic. Of the six species currently recognized, Listeria monocytogenes is the most important as it causes a range of infections in humans and animals. The organism can be found in a wide variety of habitats including the soil, food processing environments and raw foods. The ability of the organism to grow at refrigeration temperatures is of major importance in food production. This study examines the presence of Listeria species in fresh meat. 29 samples (chicken, pork and beef) meat. This bacteria was found in 82.7% of analyzed samples; 7 L. innocua, 8 L. monocytogenes and 9 L. welshimeri (of all isolates). L. innocua prevailed in pork meat (40%), L. monocytogenes in chicken and pork meat (30%), and L. welshimeri in beef meat (44.4%).

Potential for the biosynthesis of aflatoxin B1 (AFLB1), ochratoxin A (OTA), diacetoxyscirpenol (DAS), T-2 toxin (T2), and zearalenone (ZON) was investigated in different fungal species belonging to the genera: Aspergillus, Fusarium and Penicillium. The majority of investigated isolates originated from cereal grains, crushed oil soybean seed and fodder mixtures. The simple screening method developed by Filtenborg et al. (1983) was applied with few modifications concerning the type of the medium and cultivation temperature. In order to optimise the biosynthetic conditions for different mycotoxins, the following control cultures, known as mycotin producers were used: OTA - A. ochraceus CBS 108.08, DAS - F. semitectum (SL-B i SL-C), T2 - F. sporotrichioides (ITM-391, M-1-1, R-2301) and ZON - F. graminearum (GZ-LES). The fungi were cultivated on the standard medium (YESA - 2% yeast extract, 15% sucrose and 2% agar, pH 6.5), three modifications of the basic medium (YESAZn - the standard medium supplemented with 0.23 mg/l ZnSO4 x 5 H2O; PPSA - the medium in which yeast extract was replaced with peptone-1; PPSAZn - the medium in which yeast extract was replaced with peptone-1 and supplemented with 0.23 mg/l ZnSO4 x 5 H2O), and the potato-dextrose agar (PDA). The earlier biosynthesis of tested mycotoxins was recorded under the following cultivation conditions of fungal species: AFLB1 - after 14 days on PDA at 27±1°C, OTA - after 10 days on YESA and YESAZn at 27±1°C, DAS - after 10 days on PPSA and PPSAZn at 27±1°C, T2 - after 7 days on PPSAZn and PPSA at room temperature (20-24°C), and ZON - after 1 week on YESA and YESAZn at room temperature (21-24°C).

Inhibitory effect of caraway, garlic and oregano extracts (0.07, 0.1, 0.5, 1 and 2%), against four moulds species was investigated. The caraway extract had the strongest inhibitory effect by inhibiting the germination of Emericella nidulans, Penicillium commune and P. implicatum at the concentration of 0.1% and Aspergillus tamarii at the concentration of 0.5% during 7 days of incubation at 25ºC. The extract of garlic only partially inhibited the growth of A. tamarii and P. commune. However, it inhibited completely the growth of P. implicatum and E. nidulans at the doses of 0.5 and 1%. Oregano partially inhibited all mould species, significantly reducing the growth of colonies, especially of E. nidulans (93.3%).

Spices are widely used in food processing. One of the main disadvantages of spices application is their frequent microbiological spoilage. Health benefits (microbiological status, mineral and heavy metal content) of commercial ground paprika (Capsicum annuum), as well as the colour and microbiological status of its conventional and supercritical oleoresins were examined in this work.

The presence of fungi in cinnamon, marjoram, caraway and clove was investigated. Total fungal counts determined on SMA nutritive medium ranged from 8.0 (clove) to 3.3 × 104 per g (caraway) and from 6.0 to 5.2 × 104 per g on MY50G medium for the same spices. The most frequent contaminants of spice samples were the genera: Eurotium (90%), Aspergillus (80%), Penicillium (75%), Cladosporium (45%), Rhizopus, Scopulariopsis and Syncephalastrum (25%). Producers of sterigmatocystin (80%) were dominant. Producers of aflatoxin (60%) and ochratoxin A (30%) were isolated from the samples.

The antifungal activity of spice extracts obtained from caraway seed, garlic and origanum was tested against antifungal activity of Eurotium herbariorum E. amstelodami, Aspergillus flavus and A. sydowii. Caraway seed extract has been proved to possess the highest inhibitory effect on all investigated mould species. The concentrations of caraway extract, sufficient to inhibit the growth completely were: 0,5% for E. herbariorum, E. amstelodami and A. sydowii, and 1% for A. flavus; of garlic, 1% for Eurotium spp. and 2% for A. sydowii, and of origanum, 1% for E. herbariorum and 2% for E. amstelodami. The results of colonies diameter measuring showed that garlic and origanum extracts have no significant suppressing ability on micellar growth of A. flavus, while garlic was more efficient in other test cultures.

The presence of moulds, potential producers of sterigmatocystine, was investigated in 20 samples of spices (cinnamon, caraway, marjoram and clove). The following five species were isolated from the samples: Aspergillus versicolor, Aspergillus sydowii, Aspergillus ustus, Emericella nidulans and Eurotium herbariorum. E. herbariorum was present in all the investigated spice samples, accounting for 7.6% of total mycopopulation in caraway and 42.9% in cloves. A. versicolor was detected in cinnamon, caraway and marjoram, accounting for 0.4% of total mycopopulation in caraway and 1.5% in cinnamon; A. ustus accounted for 0.1% of total mycopopulation in caraway and 0.4% in marjoram, while A. sydowii accounted for 18.9% of total mycopopulation in marjoram and 7.1% in clove. E. nidulans was a contaminant of caraway (0.01%) and marjoram (0.4%). .

Strains synthesizing extracellular polysaccharide dextran on a medium with 10% sucrose were isolated from different kind of vegetables (cabbage, cucumber, cauliflower, kohlrabi, carrot, green beans, red beet, pepper, eggplant, radish). Carbohydrate fermentation was examined using a bioMerieux API 50 CHL test system. Among micropopulations with characteristic spherical cell morphology, 94.9% belonged to Leuconostoc mesenteroides subsp. mesenteroides and 5.1% were identified as Leuconostoc mesenteroides subsp. dextranicum. According to fermentation of pentoses L. mesenteroides strains were divided into three groups with a certain number of biotypes; 10 strains were tested on acid production. .

The presence of fungi was investigated in 22 samples of different dried plant origin products used for the preparation of muesli (grain products, dried fruit, nuts, oilseeds), using three media. The determined contamination levels were between 0,6% (grain products) and 46,4% (raisins). The xerotolerant Aspergillus, Penicillium and Eurotium species, mostly toxigenic and fungi from Rhizopus genera, were the most frequent in the investigated samples. Aflatoxin B1 (AB1) was not detected in any sample, while aflatoxin G1 (AG1) was found in one almond sample (0,14 μg/kg). Two almond samples were contaminated with ochratoxin A (OA), 8,00 and 16,00 μg/kg, and one sunflowerseed sample had it in traces. Zearalenone was found in two sunflowerseed samples (120,00 and 200,00 _g/kg).

The growth of fungi on food causes physical and chemical changes, which further negatively affect the sensory and nutritive quality of food. Species from genera: Aspergillus, Penicillium, Fusarium, Alternariа, Cladosporium, Mucor, Rhizopus, Eurotium and Emericella are commonly found in food. Some of them are potentially dangerous for humans and animals, due to possible synthesis and excretion of toxic secondary metabolites – mycotoxins into the food. Their toxic syndromes in animals and humans are known as mycotoxicoses. The pathological changes can be observed in parenchymatous organs, and in bones and central nervous system also. Specific conditions are necessary for mycotoxin producing fungi to synthetize sufficient quantities of these compounds for demonstration of biological effects. The main biochemical paths in the formation of mycotoxins include the polyketide (aflatoxins, sterigmatocystin, zearalenone, citrinine, patulin), terpenic (trichothecenes), aminoacid (glicotoxins, ergotamines, sporidesmin, malformin C), and carbonic acids path (rubratoxins). Aflatoxins are the most toxigenic metabolites of fungi, produced mostly by Aspergillus flavus and A. parasiticus species. Aflatoxins appear more frequently in food in the tropic and subtropic regions, while the food in Europe is more exposed to also very toxic ochratoxin A producing fungi (A. ochraceus and some Penicillium species). The agricultural products can be contaminated by fungi both before and after the harvest. The primary mycotoxicoses in humans are the result of direct intake of vegetable products contaminated by mycotoxins, while the secondary mycotoxicoses are caused by products of animal origin. The risk of the presence of fungi and mycotoxin in food is increasing, having in mind that some of them are highly thermoresistant, and the temperatures of usual food sterilization is not sufficient for their termination. The paper presents the review of most important mycotoxins, their biologic effects, the condition of their synthesis, occurrence in food, permitted tolerant intake, as well as the possibility of their degradation. [ABSTRACT FROM AUTHOR]