Czech Journal of Food Sciences, 2020 (vol. 38), issue 3

Grapevine extracts and their effect on selected gut-associated microbiota: In vitro studyOriginal Paper

Michaela Rollová, Lucia Gharwalová, Aleš Krmela, Věra Schulzová, Jana Hajšlová, Petr Jaroš, Irena Kolouchová, Olga Maťátková

Czech J. Food Sci., 2020, 38(3):137-143 | DOI: 10.17221/308/2019-CJFS  

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...

The effect of yeast generations on fermentation, maturation and volatile compounds of beerOriginal Paper

Krzysztof Kucharczyk, Tadeusz Tuszyński, Krzysztof Żyła, Czesław Puchalski

Czech J. Food Sci., 2020, 38(3):144-150 | DOI: 10.17221/193/2018-CJFS  

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)....

Discrimination of Thymus, Origanum, Satureja and Thymbra species from the family Labiatae by untargeted metabolomic analysisOriginal Paper

Nurcan Aysar Guzelsoy, Filiz Çavuş, Oya Kaçar

Czech J. Food Sci., 2020, 38(3):151-157 | DOI: 10.17221/153/2019-CJFS  

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...

Characterisation of the total phenolic, vitamins C and E content and antioxidant properties of the beebread and honey from the same batchOriginal Paper

Tomasz Sawicki, Natalia Bączek, Małgorzata Starowicz

Czech J. Food Sci., 2020, 38(3):158-163 | DOI: 10.17221/312/2019-CJFS  

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...

Effects of monoacylglycerols and chitosan on the biogenic amine formation in the flesh of rainbow trout (Oncorhynchus mykiss)Original Paper

Kateřina Matějková, Martin Křížek, Eva Dadáková, František Vácha, Tamara Pelikánová

Czech J. Food Sci., 2020, 38(3):164-170 | DOI: 10.17221/310/2019-CJFS  

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...

Palm date (Phoenix dactylifera) seeds: A rich source of antioxidant and antibacterial activitiesOriginal Paper

Abuelgassim Omer Abuelgassim, Mohamed Abdellatif Eltayeb, Farid Shokry Ataya

Czech J. Food Sci., 2020, 38(3):171-178 | DOI: 10.17221/269/2019-CJFS  

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....

Comparative analysis of riboflavin and thiamine in raw and commercial honeyOriginal Paper

Slavica Sunarić, Jelena Živković, Ana Spasić, Jelena Lalić, Jelena Matejić

Czech J. Food Sci., 2020, 38(3):179-184 | DOI: 10.17221/331/2019-CJFS  

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...

Production of butyric acid at constant pH by a solventogenic strain of Clostridium beijerinckiiOriginal Paper

Marek Drahokoupil, Petra Patáková

Czech J. Food Sci., 2020, 38(3):185-191 | DOI: 10.17221/95/2020-CJFS  

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...

Acceptance of bars with edible insects by a selected group of students from Tri-City, PolandOriginal Paper

Joanna Bartkowicz, Ewa Babicz-Zielińska

Czech J. Food Sci., 2020, 38(3):192-197 | DOI: 10.17221/236/2019-CJFS  

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...

Genetic features of Czech blue poppy (Papaver somniferum L.) revealed by DNA polymorphismShort Communication

Pavel Svoboda, Jakub Vašek, Pavel Vejl, Jaroslava Ovesná

Czech J. Food Sci., 2020, 38(3):198-202 | DOI: 10.17221/23/2020-CJFS  

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...