The aim of this study was to test the antimicrobial activity of propolis, bee pollen loads and beeswax samples collected in the year 2009 from two locations in Slovakia to pathogenic bacteria, microscopic fungi and yeasts. The antimicrobial effect of the bee product samples were tested using the agar well diffusion method. For extraction, 99.9% and 70% methanol (aqueous, v/v) and 96% and 70% ethanol (aqueous, v/v) were used. Five different strains of bacteria, i.e. Listeria monocytogenes ccM 4699, Pseudomonas aeruginosa ccM 1960; Staphylococcus aureus ccM 3953; Salmonella enterica ccM 4420, Escherichia coli ccM 3988, three different strains of microscopic fungi, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, and seven different strains of yeasts Candida krusei, Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Geotrichum candidum, Rhodotorula mucilaginosa, were tested. After 48 hours S. aureus was the bacterium most sensitive to the 70% ethanol extract of pollen, A. fumigatus was the most sensitive microscopic fungus (70% ethanol) and C. glabrata the most sensitive yeast (70% methanol). Microorganisms most sensitive to propolis extracts were L. monocytogenes, A. fumigatus (70% ethanol) and G. candidum (70% methanol). Most sensitive to beeswax extracts were E. coli, A. niger and C. tropicalis.

As the honey-bee gastrointestinal tract microflora and pollen are the primary sources for the honey microbial community, the aim of this work was to study and characterize the microbial transit among them. Therefore, an exhaustive microbial analysis of honey, adult honey-bee gastrointestinal tract, and pollen from different Slovakian regions and different seasons, was conducted. Microbial screening revealed that the primary sources of microbial community present in Slovakian honey are pollen and the honey-bees' digestive tract microflora, containing microorganisms normally present in dust, air and flowers. We found that the digestive tract of Slovakian adult honey-bees is highly populated by anaerobic, rather than aerobic bacteria, where coliforms, enterococci, staphylococci, Bacillus sp., Pseudomonas sp., microscopic fungi and yeast were found. Interestingly, statistical differences were found between the microflora of the gastrointestinal tract of summer and winter bees. Pollen revealed the presence of mesophil anaerobic and aerobic microorganisms, coliforms and microscopic fungi. Among these, the most representative genera were Alternaria, Cladosporium and Penicillium . In honey the counts of total anaerobic and total aerobic bacteria, that of coliforms, enterococci, bacilli, microscopic fungi and yeasts were monitored. Most frequently microscopic fungi belonging to genera Penicillium, Cladosporium and Alternaria were found.

Contamination by microscopic fungi and mycotoxins in different bee pollen samples, which were stored under three different ways of storing as freezing, drying and UV radiation, was investigated. During spring 2009, 45 samples of bee-collected pollen were gathered from beekeepers who placed their bee colonies on monocultures of sunflower, rape and poppy fields within their flying distance. Bee pollen was collected from bees’ legs by special devices placed at the entrance to hives. Samples were examined for the concentration and identification of microscopic fungi able to grow on Malt and Czapek-Dox agar and mycotoxins content [deoxynivalenol (DON), T-2 toxin (T-2), zearalenone (ZON) and total aflatoxins (AFL), fumonisins (FUM), ochratoxins (OTA)] by direct competitive enzyme-linked immunosorbent assays (ELISA). The total number of microscopic fungi in this study ranged from 2.98 ± 0.02 in frozen sunflower bee pollen to 4.06 ± 0.10 log cfu.g⁻¹ in sunflower bee pollen after UV radiation. In this study, 449 isolates belonging to 21 fungal species representing 9 genera were found in 45 samples of bee pollen. The total isolates were detected in frozen poppy pollen 29, rape pollen 40, sunflower pollen 80, in dried poppy pollen 12, rape pollen 36, sunflower 78, in poppy pollen after UV radiation treatment 54, rape 59 and sunflower 58. The most frequent isolates of microscopic fungi found in bee pollen samples of all prevalent species were Mucor mucedo (49 isolates), Alternaria alternata (40 isolates), Mucor hiemalis (40 isolates), Aspergillus fumigatus (33 isolates) and Cladosporium cladosporioides (31 isolates). The most frequently found isolates were detected in sunflower bee pollen frozen (80 isolates) and the lowest number of isolates was observed in poppy bee pollen dried (12 isolates). The most prevalent mycotoxin of poppy bee pollen was ZON (361.55 ± 0.26 μg.kg⁻¹), in rape bee pollen T-2 toxin (265.40 ± 0.18 μg.kg⁻¹) and in sunflower bee pollen T-2 toxin (364.72 ± 0.13 μg.kg⁻¹) in all cases in frozen samples.

The purpose of this study was to evaluate the content of selected elements and physicochemical indicators of the honey of Apis mellifera. Samples of blossom, blend and honeydew honeys were randomly obtained from the Eastern, Western and Central of Slovakia. Contents of elements were measured with the use of flame atomic absorption spectrophotometry (FAAS) method and anodic stripping voltammetry (ASV) method with CGMDE as working electrode. The content of heavy metals (mg/kg dry weight) ranged as follows: Zn 0.25–3.82; Cu 0.12–1.37; Ni 0.06–0.60; Mg 0.10–50.43; Ca 10.32–87.21; Pb and Cd were under detectable limit (0.001 mg/kg). The physical and chemical indicators ranged as follows: moisture (%) 16.00–19.80; HMF (mg/kg) 10.00–40.00; pH 3.58–5.12; conductivity (mS/m) 13.45–99.12 and a _w 0.456–0.659. Significant difference (P < 0.05) for elements and physicochemical indicators was analyzed. Significant correlations between Cu – Zn, Cu – Ni, Cu – Mg, Ca – Zn and Ca – Mg were detected. With reference to Codex Alimentarius of Slovakia, maximal levels of heavy metals content and selected physicochemical properties were not exceeded. On average, the content of trace elements decreased in the order: Ca > Mg > Zn > Cu > Ni and physicochemical indicators decreased: conductivity > HMF > moisture > pH > a_w.

The aim of the present work was to evaluate the microbiological quality of chicken thighs after treatment by fennel (Foeniculum vulgare) and savory (Satureja hortensis) essential oil, stored under vacuum packaging (VP) at 4 ± 0.5 °C for a period of 16 days. The following treatments of chicken thighs were used: Air-packaging control samples (APCS), vacuum-packaging control samples (VPC), vacuum-packaging (VP) control samples with rapeseed oil (VPRO), VP (vacuum-packaging) with fennel essential oil at concentrations 0.2% v/w (VP + F), and VP with savory essential oil at concentration 0.2% v/w (VP + S). The quality assessment of APCS, VPC, VPRO, VP + F and VP + S products was established by microbiological analysis. The microbiological parameters as the total viable counts of bacteria of the Enterobacteriaceae family, lactic acid bacteria (LAB), and Pseudomonas spp. were detected. Bacterial species were identified with the MALDI-TOF MS Biotyper. The combination of essential oils and vacuum packaging had a significant effect (p < 0.05) on the reduction of total viable counts (TVC) compared with control group without vacuum packaging and the untreated control group. Though 15 genera and 46 species were isolated with scores higher than 2.3 from the chicken samples.