National Repository of Grey Literature 7 records found  Search took 0.00 seconds. 
Characterization of new czech hop varieties
Faruzel, Vojtěch ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
In this thesis the problem of characterization of new Czech hop varieties was investigated. The selected new varieties were Mimosa, Jazz and Blues. Their composition was compared with the widely used varieties Žatecký poloraný červeňák and Kazbek. The content of -bitter acids and -bitter acids, total phenolic content, flavonoid content and antioxidant activity were determined by UV-VIS spectroscopy for all hop varieties. The composition of hop essential oils was estimated by SPME-GC-MS. The diversity of the hop varieties was confirmed from the measured data by statistical analysis. The new varieties showed statistically significant differences in all monitored parameters, especially in comparison with the varieties Žatecký poloraný červeňák and Kazbek. The quantitatively different representation of -bitter acids and -bitter acids has an influence on the character and intensity of bitterness of these hop varieties. The composition of the hop essential oils, the content of phenolic substances, flavonoids and antioxidant activity are reflected in the different organoleptic properties of the hops analysed and of the beer.
Pharmacologically active compounds in hops
Pýchová, Kateřina ; Cvrčková, Fatima (advisor) ; Mašková, Petra (referee)
The hop plant (Humulus lupulus) is used not only in brewing but also in phytopharmacology and phytotherapy. Among the isolated or chemically produced substances used for healing are xanthohumol, 8-prenylnaringenine and α and β-bitter acids. Nowadays, a lot of attention is paid to their effect on humans - especially to their anticancer activity. But there is a lack of information about the importance of these substances for the hop plant itself. Most of the plant secondary metabolites originally serve for protection of the plant against pathogens and herbivores. The selected metabolites are not an exception. The purpose of this work was to summarize the published data about the biological importance of selected hop secondary metabolites and the effects they have on other organisms than plants, with an emphasis on humans.
Vliv technologie zpracováni na senzorickou jakost chmelových výhonků
Komárková, Natálie
The diploma thesis “Impact of technology of manufactory to sensory quality of hop sprouts” was made according to requests from company Chuť Moravy s.r.o., which uses young hop sprouts in its manufacturing processes. Due to unsatisfying sensory quality of the product of young hop sprouts, the technology of manufacture was subject of this investigation. Eighteen variants of manufacturing processes have been suggested, varying in term of picking, kind of species of hop Žatecký poloraný červeňák, soaking (during night) or not soaking of the plant, suffusion by warm or cold pickle and quick or slow cooling. These processes were carried out in the second half of April 2018 and during November the same year the samples were tested. The results of sensory analysis of pasteurized hop sprouts show statistically significant differences (p < 0,05) among individual manufacturing processes. The best-rated process was: pasteurization on 18. 4. 2018, plant before cutting, Osvalds clone No 72, planted in 2014, sample soaked, cold pickle, quick cooling (process 1) and slow cooling (process 2).
Pharmacologically active compounds in hops
Pýchová, Kateřina ; Cvrčková, Fatima (advisor) ; Mašková, Petra (referee)
The hop plant (Humulus lupulus) is used not only in brewing but also in phytopharmacology and phytotherapy. Among the isolated or chemically produced substances used for healing are xanthohumol, 8-prenylnaringenine and α and β-bitter acids. Nowadays, a lot of attention is paid to their effect on humans - especially to their anticancer activity. But there is a lack of information about the importance of these substances for the hop plant itself. Most of the plant secondary metabolites originally serve for protection of the plant against pathogens and herbivores. The selected metabolites are not an exception. The purpose of this work was to summarize the published data about the biological importance of selected hop secondary metabolites and the effects they have on other organisms than plants, with an emphasis on humans.
Antimicrobial activity of extract from GRAS plant species agains oral pathogenic microorganisms
Pilná, Jindřiška ; Kokoška, Ladislav (advisor) ; Jaroslav, Jaroslav (referee)
Microbial oral diseases such as caries and periodontitis are among the most frequent human infections. Conventional chemical antiseptics used for their treatment and prevention often produce adverse side-effects, which restrict their long-term use. Although plants are considered as perspective sources of novel antimicrobial compounds, little is still known about their inhibitory properties against oral pathogens and about their safety while used on a daily basis. The objective of this study was to investigate in vitro growth-inhibitory effects of ethanol Generally Recognised as Safe (GRAS) plant and supercritical CO2 hop extracts on planktonic cultures of cariogenic, periodontal and candidal human pathogens, namely Aggregatibacter actinomycetemcomitans, Bifidobacterium dentium, B. longum, Candida albicans, Eikenella corrodens, Fusobacterium nucleatum subsp. vincentii, Lactobacillus salivarius subsp. salivarius, Porphyromonas gingivalis, Streptococcus mutans, S. salivarius subsp. salivarius and S. sobrinus using the broth microdilution method. The findings showed that ethanol extracts of all 109 GRAS plant species inhibited the growth of at least one microorganism under study with minimum inhibitory concentration (MIC) equal or lower than 4096 ug/mL. However, only six of them possessed very interesting antiseptic potential against the oral pathogens with MIC < 100 ug/mL. Additionally, three GRAS plant species showed good inhibitory activity with MIC = 128 ug/mL. As far as the particular results are concerned, the best antiseptic effect was observed for both Humulus lupulus CO2 supercritical and ethanol extracts that inhibited the growth of all microorganisms at MICs higher or equal to 8 ug/mL and MICs higher or equal to 16 ug/mL, respectively. Hence, the CO2 supercritical extraction proved to be superior for extraction of active constituents of H. lupulus. Further, the ethanol extracts of Capsicum annuum and C. frutescens showed significant antiseptic potential against S. sobrinus and S. salivarius (MICs from 64 to 128 ug/mL). The oral streptococci were also inhibited by Zanthoxylum clava-herculis (MIC higher or equal to 64 ug/mL), Helichrysum angustifolium and Myristica fragrans (MIC higher or equal to 128 ug/mL) which further showed the antimicrobial activity against F. nucleatum (MIC = 64 ug/mL). Interesting inhibitory effects exhibited an extract of Punica granatum against C. albicans (MIC = 128 ug/mL) and F. nucleatum (MIC = 64 ug/mL). Moreover, the growth of F. nucleatum was inhibited by extracts of Pimenta officinalis and Thea sinensis (MIC = 128 ug/mL). The chemical analysis of the CO2 supercritical H. lupulus extracts revealed that alpha and beta bitter acids represented the two major groups of constituents. Cohumulone was the predominant compound of the alpha acids, whereas colupulone was the prevalent constituent of the beta acids. Our results suggest that the six GRAS plant species, namely C. annuum, C. frutescens, H. lupulus, M. fragrans, P. granatum and Z. clava-herculis have good potential to become new safe antiseptic agents that might be used for incorporation into oral care products such as toothpastes and mouthrinses.
Variabilita obsahu silic ve chmelových šišticích
Křížová, Alena
This thesis deals with the variability of hop oils in the hop cones. Hops is the most important raw material for the production of beer and hop oils are the most important group of compounds responsible for the aroma of hops and thus the beer. Essential oils are applied in commercial quality assessment of cone hops for beer production. Essential oils have also hop buffer and antibacterial effects and pharmacology are used for suppressing agitation, restlessness and insomnia. Essential oils are complex mixtures of hundreds of natural compounds of different chemical composition. They represent a mixture of carbon compounds, oxygen compounds and sulfur compounds. The content of hop oils in the hop cones depends on the genetic characteristics of the variety, growing area, the average temperature, rainfall, and other conditions cultivation. This work was performed by steam distillation determination of hop oils. The determination was carried out on samples from 2012 and 2013, the essential oil content was profitable in 2012. Highest value of the hop oils was measured in a variety of Premiant from Tršice growing region (837 micro liters.100g-1). The lowest value then the variety Saaz classical form of the Saaz hop-growing area (220 mocro liters.100g-1).
Structure-function analysis of selected hop (Humulus lupulus L.) regulatory factors
FÜSSY, Zoltán
This work concentrated on isolation of novel hop transcription factors from bHLH, bZIP, MYB, and WRKY families involved in the regulation of lupulin flavonoid pathways, followed by their structural and functional analysis. Structural analyses included bioinformatic approaches to elucidate gene organization, domain structure of the putative protein products, and potential post-translational modifications. I performed site-directed mutagenesis to disclose the role of phosphorylation sites in HlbZIP1A stability. Further, this work determined protein-DNA interactions for obtained TFs, giving support to the binding of MYB-bHLH-WDR complexes to the promoter of chalcone synthase H1, a key enzyme of the lupulin flavonoid pathways. Employing bioinformatic approaches, quantitative RT-PCR and transient co-expression, I pointed out chalcone synthase H1 as a regulatory crossroads in the metabolic (flavonoid) responses during hop stunt viroid pathogenesis.

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