Template-Type: ReDIF-Article 1.0 Author-Name: Michaela Rollová Author-Workplace-Name: Department of Biotechnology, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Lucia Gharwalová Author-Workplace-Name: Department of Biotechnology, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Aleš Krmela Author-Workplace-Name: Department of Food Analysis and Nutrition, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Věra Schulzová Author-Workplace-Name: Department of Food Analysis and Nutrition, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Jana Hajšlová Author-Workplace-Name: Department of Food Analysis and Nutrition, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Petr Jaroš Author-Workplace-Name: Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Irena Kolouchová Author-Workplace-Name: Department of Biotechnology, University of Chemistry and Technology, Prague, Czech Republic Author-Name: Olga Maťátková Author-Workplace-Name: Department of Biotechnology, University of Chemistry and Technology, Prague, Czech Republic Title: Grapevine extracts and their effect on selected gut-associated microbiota: In vitro study Abstract: The biological activity of polyphenol substances contained in food supplements prepared from Vitis vinifera can affect the microorganisms present in the digestive tract in terms of their representation and activity of the individual species. This study deals with resveratrol and two polyphenol-rich extracts (extract from V. vinifera canes and the commercial product Regrapex-R-forte) and their effect on selected gut microbiota (Bifidobacterium animalis subsp. lactis Bb-12, Lactobacillus acidophilus LA-5, Lactobacillus casei Lafti L-26, Citrobacter freundii DBM 3127, Escherichia coli DBM 3125). The effect of the studied agents on planktonic and biofilm growth of the microorganisms was determined as minimum inhibitory concentration (MIC80) and minimum biofilm inhibitory concentration (MBIC80), respectively. The extracts induced metabolic activity as well as total biofilm biomass production in probiotic strain L. acidophilus LA-5 while successfully inhibiting the growth of opportunistic pathogenic microorganisms C. freundii DBM 3127 and E. coli DBM 3125. Keywords: anti-biofilm activity, gut microbiota, polyphenols, resveratrol, Vitis vinifera Journal: Czech Journal of Food Sciences Pages: 137-143 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/308/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/308/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0001.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:308-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Krzysztof Kucharczyk Author-Workplace-Name: Cracow School of Health Promotion, Cracow, Poland Author-Name: Tadeusz Tuszyński Author-Workplace-Name: Cracow School of Health Promotion, Cracow, Poland Author-Name: Krzysztof Żyła Author-Workplace-Name: Department of Food Biotechnology, Food Technology, University of Agriculture in Cracow, Cracow, Poland Author-Name: Czesław Puchalski Author-Workplace-Name: Faculty of Biology and Agriculture, University of Rzeszów, Rzeszów, Poland Title: The effect of yeast generations on fermentation, maturation and volatile compounds of beer Abstract: The aim of the study was to determine the effect of yeast generations on fermentation and maturation processes, the content of volatile compounds of beer and viability and vitality of yeast biomass on an industrial scale. The experiments with fermentation and maturation were performed in fermentation tanks. The wort was aerated with sterile air. Yeast (S. pastorianus) bottom fermentation was used in fermentation. For pitching four generations (passages) of yeast were used as follows: 1st, 2nd, 3rd and 4th generation. The processes of fermentation and maturation were carried out in the same technological conditions (temperature and pressure). During fermentation and maturation, the changes in the content of the extract, yeast growth and vitality and selected volatile compounds like esters, alcohols and carbonyl compounds were investigated. With the increase in the number of yeast generations, especially from the 2nd generation used in the fermentation process, the content of acetaldehyde and esters increased. Despite the slight differences between generations, the changes are statistically significant. The content of diacetyl is stable for the 1st, 2nd and 3rd generation and higher for the 4th generation. Diversified yeast generations used in the process of fermentation did not affect significantly the final quality of beer. Keywords: wort, yeast generation, fermentation, volatile compounds, beer Journal: Czech Journal of Food Sciences Pages: 144-150 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/193/2018-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/193/2018-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0002.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:193-2018-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Nurcan Aysar Guzelsoy Author-Workplace-Name: Department of Food Authenticity, Central Research Institute of Food and Feed Control, Ministry of Agriculture and Forestry, Bursa, Turkey Author-Name: Filiz Çavuş Author-Workplace-Name: Department of Food Authenticity, Central Research Institute of Food and Feed Control, Ministry of Agriculture and Forestry, Bursa, Turkey Author-Name: Oya Kaçar Author-Workplace-Name: Department of Field Crops, Uludag University, Faculty of Agriculture, Bursa, Turkey Title: Discrimination of Thymus, Origanum, Satureja and Thymbra species from the family Labiatae by untargeted metabolomic analysis Abstract: The term "thyme" does not refer to herbs that belong to a single species. The genera Thymus, Origanum, Satureja and Thymbra of the family Labiatae are traditionally named as thyme and locally known as 'kekik'. Unlike Turkey, these species are globally called differently. Spices made of Origanum, Thymus and Satureja are called oregano, thyme and savory, respectively. It is often difficult to differentiate them because of their similar smell and appearance. Most commercial products traded as a mixture of those genera and the mixing together of different species may lead to economically motivated adulteration and a product of reduced value. The species were analysed by LC-ESI-QTOF-MS and a comprehensive statistical workflow was designed. The data of methanolic extracts were assessed and an extraction algorithm was employed for the processing of raw data. Five species were discriminated using principal component analysis (PCA) and hierarchical cluster analysis (HCA). The results of PCA and HCA were consistent with each other. Twenty-one metabolites were determined for the discrimination. Keywords: LC-QTOF, plant metabolomics, multivariate data analysis, thyme Journal: Czech Journal of Food Sciences Pages: 151-157 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/153/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/153/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0003.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:153-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Tomasz Sawicki Author-Workplace-Name: Department of Human Nutrition, Faculty of Food Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland Author-Workplace-Name: Department of Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland Author-Name: Natalia Bączek Author-Workplace-Name: Department of Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland Author-Name: Małgorzata Starowicz Author-Workplace-Name: Department of Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research Polish Academy of Sciences, Olsztyn, Poland Title: Characterisation of the total phenolic, vitamins C and E content and antioxidant properties of the beebread and honey from the same batch Abstract: The aim of this study was to compare total phenolic and flavonoid content, antioxidant and reducing activity, as well as vitamin C and E content in beebread and honey. The antioxidant activity of samples was determined by photochemiluminescence (PCL) assay, while reducing potential was measured using FRAP and ORAC assays. Vitamin C was analysed by HPLC-MS-TripleTOF method and vitamin E by HPLC-DAD. Beebread was characterised by the higher level of the total phenolic (~90%), flavonoid (~97%), vitamin C (~99%) and E (~98%) as compared to the honey. The data showed that beebread had also higher values of antioxidant activity and reducing potential by ~99% and ~41-98%, respectively, than honey. Our findings indicate that beebread is valuable source of bioactive substances, with the high beneficial properties. Keywords: antioxidant status, ascorbic acid, bee products, lipid-soluble antioxidants, phenolics and flavonoids, reducing capacity Journal: Czech Journal of Food Sciences Pages: 158-163 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/312/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/312/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0004.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:312-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Kateřina Matějková Author-Workplace-Name: Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, Czech Republic Author-Name: Martin Křížek Author-Workplace-Name: Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, Czech Republic Author-Name: Eva Dadáková Author-Workplace-Name: Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, Czech Republic Author-Name: František Vácha Author-Workplace-Name: Department of Agricultural Products Quality, Faculty of Agriculture, University of South Bohemia, Czech Republic Author-Name: Tamara Pelikánová Author-Workplace-Name: Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, Czech Republic Title: Effects of monoacylglycerols and chitosan on the biogenic amine formation in the flesh of rainbow trout (Oncorhynchus mykiss) Abstract: Contents of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined in vacuum-packed fillets of rainbow trout (Oncorhynchus mykiss). Fish flesh was treated using a solution of chitosan (2%, w/v) or monoacylglycerols (monocaprylin C8, monocaprin C10, 5%, w/v). The control and treated packs were stored at 3.5 °C for up to 25 days. Samples of good quality did not contain more than 30 mg kg-1 of either putrescine or cadaverine. Exceeding this limit was usually followed by a worsening of the sensory properties of samples. Chitosan was found to be the most potent additive, prolonging the storage time of fillets by approximately four times, compared to control samples. Histamine was not found in any sample treated with chitosan. of the monoacylglycerols, C8 was more efficient compared to C10. All additives are easily applicable to the surface of fish flesh. Keywords: polyamines, putrescine, histamine, fish quality, shelf life Journal: Czech Journal of Food Sciences Pages: 164-170 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/310/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/310/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0005.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:310-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Abuelgassim Omer Abuelgassim Author-Workplace-Name: Biochemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia Author-Name: Mohamed Abdellatif Eltayeb Author-Workplace-Name: Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia Author-Name: Farid Shokry Ataya Author-Workplace-Name: Biochemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia Title: Palm date (Phoenix dactylifera) seeds: A rich source of antioxidant and antibacterial activities Abstract: Two varieties of palm date seeds (PDS), Sukkari and Khalas, were examined for their antioxidant and antibacterial activities. Total phenol content was 2 014.37 ± 212.05 and 2 060.40 ± 176.0 mg GAE 100 g-1 dry weight (DW); and total flavonoid content was 83.98 ± 1.10 and 94.97 ± 1.36 mg QE 100 g-1 DW for Sukkari and Khalas, respectively. PDS extracts showed potential scavenging activity against ABTS, DDPH, and hydroxyl radical; the calculated IC50s were 431.17 ± 12.45, 400 ± 10.87 and 680 ± 18.12 µg for Sukkari, and 476 ± 20.25, 302.24 ± 14.08 and 284.18 ± 11.62 µg for Khalas, respectively. PDS extracts did not show potential activity against superoxide anion. Both extracts showed a high percentage of reducing power as the calculated FRAP (ferric reducing antioxidant power) concentrations were 12.66 ± 1.08 and 16.14 ± 1.94 mmol ascorbic acid equivalent 100 g-1 for Sukkari and Khalas, respectively. Bacillus subtilis showed a remarkable sensitivity to PDS extracts; the inhibition zones were 21 ± 0.82 and 22 ± 0.67 mm for Sukkari and Khalas, respectively. PDS extracts possess good antioxidant and antibacterial activity, and therefore PDS could be effectively used as a natural source of antioxidants and to be detected against gram-positive bacteria. Keywords: free radicals, gram-positive bacteria, phenolic acids, scavenging activity, total flavonoids, total phenols Journal: Czech Journal of Food Sciences Pages: 171-178 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/269/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/269/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0006.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:269-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Slavica Sunarić Author-Workplace-Name: Department of Chemistry, Faculty of Medicine, University of Niš, Niš, Serbia Author-Name: Jelena Živković Author-Workplace-Name: Department of Chemistry, Faculty of Medicine, University of Niš, Niš, Serbia Author-Name: Ana Spasić Author-Workplace-Name: Department of Pharmacy, Faculty of Medicine, University of Niš, Niš, Serbia *Corresponding author e-mail: slavica.sunaric@medfak.ni.ac.rs Author-Name: Jelena Lalić Author-Workplace-Name: Department of Pharmacy, Faculty of Medicine, University of Niš, Niš, Serbia *Corresponding author e-mail: slavica.sunaric@medfak.ni.ac.rs Author-Name: Jelena Matejić Author-Workplace-Name: Department of Pharmacy, Faculty of Medicine, University of Niš, Niš, Serbia *Corresponding author e-mail: slavica.sunaric@medfak.ni.ac.rs Title: Comparative analysis of riboflavin and thiamine in raw and commercial honey Abstract: The paper describes the determination of riboflavin and thiamine in the best-selling types of 13 raw and 8 commercial monofloral and multifloral honeys originating from Serbia. It was found that there is a difference in average riboflavin and thiamine content between raw and commercial honey, as well as between different honey floral varieties. The results showed that forest, meadow and oregano honey had a significantly higher content of both B vitamins compared to acacia, linden and lavender honey. On the other hand, a very low content of riboflavin and thiamine was found in honeydew honey. Among the commercial products, royal jelly was the richest in thiamine and riboflavin, followed by forest honey. In general, the quality of all of the commercial honey samples regarding these vitamins was lower than that of the raw domestic honeys. Keywords: honeydew, monofloral honey, multifloral honey, royal jelly, vitamins Journal: Czech Journal of Food Sciences Pages: 179-184 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/331/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/331/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0007.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:331-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Marek Drahokoupil Author-Workplace-Name: Department of Biotechnology, University of Chemistry and Technology Prague, Prague, Czech Republic Author-Name: Petra Patáková Title: Production of butyric acid at constant pH by a solventogenic strain of Clostridium beijerinckii Abstract: A solventogenic strain of Clostridium beijerinckii, NRRL B-598, was cultured for the production of butyric acid as the main fermentation product. However, unlike typical acetone-butanol-ethanol (ABE) fermentations, where pH is not regulated, in this study the pH was kept constant during fermentation. From the five pH values tested, 6.0, 6.5, 7.0, 7.5 and 8.0, pH 6.5 and 7.0 resulted in the highest concentrations of butyric acid, at 9.69 ± 0.09 g L-1 and 11.5 ± 0.39 g L-1, respectively. However, a low concentration of solvents, 1.8 ± 0.22 g L-1, was only reached at pH 7.0. These results are comparable with those from typical butyric acid producers, i.e. Clostridium butyricum and Clostridium tyrobutyricum strains. At pH 7.0, we succeeded in suppressing sporulation and prolonging the population viability, which was confirmed by flow cytometry combined with double fluorescence staining. Keywords: butyrate, Clostridium beijerinckii NRRL B-598, solventogenic clostridia, controlled pH, flow cytometry Journal: Czech Journal of Food Sciences Pages: 185-191 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/95/2020-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/95/2020-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0008.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:95-2020-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Joanna Bartkowicz Author-Name: Ewa Babicz-Zielińska Author-Workplace-Name: Faculty of Physiotherapy and Health Sciences at Gdansk College of Health, Gdansk, Poland Title: Acceptance of bars with edible insects by a selected group of students from Tri-City, Poland Abstract: Although entomophagy as a diet has been known since the dawn of humanity, it is still considered a novelty to the European market and consumers. This study was performed to evaluate the acceptance of a trend promoted by the FAO diet regarding selected young Polish consumers and it presents the results of a survey conducted among them. The primary goal of this study was to assess the acceptance of new edible insect products with mealworms Tenebrio molitor L. and house crickets Acheta domesticus L. These products were prepared in the form of four different types of bars; one without insects, one with whole mealworms, one with ground mealworms and one with ground crickets. According to consumers, the worst bars were the ones which contained the whole mealworms. Additionally, the main problems with accepting this product were caused by the colour of the ground crickets and visible whole pieces of the insects in the edible bars. The study proved that the acceptance of insect bars as food depends on the tastiness and smell. The acceptance of bars also depends on variants. The basic bar had the highest acceptance rate, while the bar with whole mealworms had the lowest one. Keywords: house crickets, mealworms, new food, young consumers, entomophagy Journal: Czech Journal of Food Sciences Pages: 192-197 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/236/2019-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/236/2019-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0009.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:236-2019-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Pavel Svoboda Author-Workplace-Name: Division of Crop Genetics and Breeding, Crop Research Institute, Prague, Czech Republic Author-Name: Jakub Vašek Author-Workplace-Name: Department of Genetics and Breeding, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Pavel Vejl Author-Workplace-Name: Department of Genetics and Breeding, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Jaroslava Ovesná Author-Workplace-Name: Division of Crop Genetics and Breeding, Crop Research Institute, Prague, Czech Republic Title: Genetic features of Czech blue poppy (Papaver somniferum L.) revealed by DNA polymorphism Abstract: Seeds of Czech poppies used for culinary purposes are frequently mixed with seeds of imported low-quality poppies with higher alkaloid content and poor taste properties. That not only decreases the quality of the product on the market, but it can also represent a potential health hazard for consumers. To prevent such adulteration, the method is needed that could clearly detect the presence of the low-quality poppies in the products on the market and which can also confirm the authenticity of the genetic material for growers. For that reason, length polymorphism of Simple Sequence Repeats was evaluated in the blue and non-blue poppy varieties of Czech and foreign origin. Used markers clearly distinguished 'Czech blue poppy' cultivars from blue poppies of another origin as well as from poppies of non-blue seed colour. We conclude that used markers can be applied to a commodity verification on the market to detect/exclude the presence of other genotypes. Keywords: Papaver somniferum, Czech blue poppy, length polymorphism, Simple Sequence Repeats Journal: Czech Journal of Food Sciences Pages: 198-202 Volume: 38 Issue: 3 Year: 2020 DOI: 10.17221/23/2020-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/23/2020-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-202003-0010.txt Handle: RePEc:caa:jnlcjf:v:38:y:2020:i:3:id:23-2020-CJFS