The main aim of this study was to determine antioxidant properties and antibacterial activity of monofloral bee pollen samples to pathogenic bacteria. These samples were collected in different localities in Slovakia. The antioxidant properties of examined plant species were different and decreasing in the following order: Brassica napus subsp. napus L > Papaver somniferum L. > Helianthus annuus L. The antimicrobial effect of the bee product samples were tested by using the agar well diffusion method. The methanol (99.9% and 70%) and the ethanol (96% and 70%) were used for extraction. In this study, five different strains of bacteria were tested: Listeria monocytogenes CCM 4699; Pseudomonas aeruginosa CCM 1960; Staphylococcus aureus CCM 3953; Salmonella enterica CCM 4420; and Escherichia coli CCM 3988. The most sensitive bacteria of the poppy pollen ethanolic extract was Staphylococcus aureus was (70%) The most sensitive bacteria of rape bee pollen methanolic extract (70%) and sunflower ethanolic extract (70%) was Salmonella enterica.

The objective of this study was to measure the content of flavonoids, polyphenols, and carotenoids in the Helianthus annuus L. bee pollen. It was also to evaluate the ability of the dried, frozen, and freeze-dried extracts of sunflower (H. annuus) pollen, its scavenged free radicals and reducing action. Another aim of this study was to investigate the antimicrobial in vitro action of the H. annuus pollen extracts against the Gram-positive and Gram-negative bacteria and fungi. All pollen extracts showed medium antiradical activity and reductive ability. The most effective was the freeze-dried extract in both evaluation systems. The evaluation of the protective effects of DNA using a biosensor showed an opposite trending-frozen ˃ dried ˃ freeze-dried pollen. For the evaluation of antiradical activity, the DPPH method was used, and reductive ability was assessed by means of phosphomolybdic complex formation. The comparison of the polyphenols content shows higher values in freeze-dried bee pollen than in the dried and frozen pollen. The highest content of flavonoids was found in the frozen samples and the most carotenoids were present in the dried samples. In our study, the best antibacterial effects of the dried sunflower bee pollen extracts were found against Paenibacillus larvae, Pseudomonas aeruginosa, and Enterococcus raffinosus. The best inhibitory properties of the frozen sunflower bee pollen extracts were found against Escherichia coli, Pseudomonas aeruginosa, and Paenibacillus larvae. Very good inhibitory effects of freeze-dried sunflower bee pollen were found against Paenibacillus larvae, Brochotrix thermosphacta, and Enterococcus raffinosus. The best antifungal activity of the sunflower bee pollen was found in the frozen bee pollen extracts against Aspergillus ochraceus and freeze-dried bee pollen extracts against Aspergillus niger.

The aim of our work was to characterize linseed (Linum usitatissimum L.) genotypes divided into groups with high and low content of alpha-linolenic acid (ALA). Out of 32 linseed genotypes, 68.75 % represented high alpha-linolenic genotypes and 31.25 % were genotypes with low ALA content. Proportional representation of fatty acids was realized according to the norm (Czech Office for Standards, Metrology and Testing, 1994). Oil content was analyzed according to the internal methodology of Agritec Ltd., based on the norm (Czech Office for Standards, Metrology and Testing, 2011). The content of total fat ranged from 36.22 % to 46.35 %, that of ALA from 1.10 % to 65.20 %, and that of linoleic acid (LA) from 11.10 % to 75.00 % in the analyzed seed samples within all groups. The genotypes were divided also according to the seed color and a linear correlation between all three parameters within these groups was observed. Negative linear dependence was confirmed between parameters; ALA and LA content in the groups: high ALA brown seed (p < 0.0001; correlation coefficient (r) = −0.70), and high ALA yellow seed (p < 0.001; r = −0.36). Also, positive linear dependence between the total fat and the LA content in the groups: low ALA brown seed (p < 0.001; r = 0.34); low ALA yellow seed (p < 0.0001; r = 0.62), was found.

This scientific work was aimed to evaluate the antioxidant potential of aromatic plants of Thymus spp. in the East of Ukraine. These plants are known as medicinal and food around the world. All antioxidant parameters were investigated spectrophotometrically: total content of polyphenols (TPC), the total content of phenolic acids (TPAC), the total content of flavonoids (TFC), molybdenum reducing power of extracts (MRP), and antioxidant activity by DPPH method (DPPH). Investigation of ethanolic extracts demonstrated that TPC varied from 57.89 to 123.67 mg/g gallic acid equivalent (GAE) DW for Th. pulegioides, from 61.43 to 168.18 mg GAE/g for Th. serpyllum, and from 47.36 to 115.67 mg GAE/g for Th. vulgaris. TPAC ranged from 27.36 to 50.22 mg/g caffeic acid equivalent (CAE) DW for Th. pulegioides, from 28.58 to 59.62 mg CAE/g for Th. serpyllum, and from 22.95 to 53.82 mg CAE/g for Th. vulgaris. TFC was determined in a range from 29.88 to 61.23 mg/g quercetin equivalent (QE) DW for Th. pulegioides, from 36.0 to 82.43 mg QE/g for Th. serpyllum, and from 24.59 to 55.41 mg QE/g for Th. vulgaris. MRP was detected in the range of 94.65 – 204.76 mg/g Trolox equivalent (TE) DW for Th. pulegioides, 96.06 – 219.0 mg TE/g for Th. serpyllum, and 87.56 – 215.43 mg TE/g for Th. vulgaris. The antioxidant activity of extracts by the DPPH method was 6.34 – 9.23 mg TE/g for Th. pulegioides, 8.11 – 9.21 mg TE/g for Th. serpyllum, and 4.97 – 9.53 mg TE/g for Th. vulgaris. It was established that polyphenol accumulation depended on the growth stage and species. For all species was found a strong correlation between TPC and TFC (r = 0.938, 0.908, and 0.854). Investigated Thymus spp. are a valuable source of antioxidants that can be used in pharmacological studies and the food industry.

The aim of this study was to identify lactic acid bacteria (LAB) in grapes, must and wines. A total amount of 90 samples including grape (n = 30), must (no = 30) and wine (no = 30) were collected from vineyards in Slovakia. LAB were used cultured on MRS agar with subsequent confirmation with MALDI-TOF mass spectrometry (Bruker Daltonics). Altogether, 904 isolates were identified. Members of the family Lactobacillaeceae were the most abundant in grape (60%), must (46%) and wine (51%). Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella genera and 27 species of LAB were isolated from the examined samples. Leuconostoc mesenteroides spp. mesenteroides was the most abundant species in grape, must and wine.