|
| |
|
|
Assessment of chosen aromatic compounds in foods
Ascherová, Adriana ; Buňka, František (referee) ; Vítová, Eva (advisor)
This diploma thesis is focused on aromatic substances occurring in food. The theoretical part describes their characteristics, the use of fragrances of plant origin for flavoring of food and points to their possible negative effects on the human organism. Twenty six potentially allergenic fragrances are thus identified in European legislation and an overview of their physical properties, occurrence and use is also processed in this work.The aim of the experimental part was to develop and validate a method for assessment of fragrances using headspace solid phase microextraction combined with gas chromatography (HS-SPME-GC-FID). The following parameters have been validated : repeatability, linearity, limits of detection (LOD) and limits of quantification (LOQ). The HS-SPME-GC-FID method was finally applied to selected samples of foods commonly available on the market.
|
|
|
Solution design of dual food quality problem through Blockchain technology
Kopec, Martin ; Luhan, Jan (referee) ; Novák, Lukáš (advisor)
The goal of this diploma thesis is to propose a system based on blockchain technology that is dealing with dual food quality problem in countries of the EU. The theore- tical part of the thesis explains basic principles of blockchain technology, provides an analysis of the dual food quality problem, EU market and the current blockchain implementations in food industry. The practical part focuses on the solution design of such a system itself.
|
|
|
Assessment of chosen aromatic compounds in foods
Škopová, Jitka ; Buňka, František (referee) ; Vítová, Eva (advisor)
The thesis deals with the issue of potentially allergenic aroma compounds in food. Aroma compounds suitable for food flavouring are mainly of plant origin. These aroma compounds and their mixtures have a lot of positive and negative effects on human organism. Although the aroma compounds are not among main groups of allergens, several studies indicate a potential risk of allergenic effects of some aroma compounds. The theoretic part of this thesis focuses on aroma compounds of plant origin and gives an overview of 26 the most important fragrance allergens according to the European cosmetic legislation. The aim of the experimental part was to verify the selectivity and appropriateness of the currently used methodology of headspace solid-phase microextraction and gas chromatography-flame ionization detection (HS-SPME-GC-FID) for determination of selected allergenic aromatic active compounds. Secondly, it is to use a proven method for a wide spectrum of real food products.
|
|
|
Isolation of bacterial DNA from foods using magnetic carriers
Bubeníková, Lucia ; Horák, Daniel (referee) ; Španová, Alena (advisor)
The aim of the work was the selective isolation of bacterial DNA with help of magnetic carriers covered by streptavidine (PGMA-NH2-STV, MPG® Streptavidin). Conditions of functionalisation of carriers using two biotinylated probes were optimized: the amount of carrier, the amount of probe, binding of biotinyled probe to streptavidine. Purified DNA Lactobacillus was used for hybridization. DNA binding to the probe (DNA/DNA hybridization) and nospecific adsorption of DNA to the carrier were tested. Target DNA eluted from the carrier was identified using PCR with primers R16-1 and LbLMA1-rev and with primers P_eub and F_eub. The amount of probe bound to the carrier was estimated using UV spectrophotometry. It was estimated that biotinyled probe can be used for functionalisation in concentration 5 pmol/µl added to the carrier in the ration carrier : probe 1:1. It was shown that nonspecific DNA adsorption to the MPG® Streptavidin is significantly lower than to the carrier PGMA-NH2-STV.Using DNA/DNA hybridization and the MPG® Streptavidin, DNA from pure culture Lactobacillus was isolated. Procedure was applicated for DNA isolation from milk products.
|
|
|
Assessment of aromatic compounds of plant origin in foods
Jelínková, Monika ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
The aroma compounds suitable for food flavouring are mainly of plant origin. It is necessary to take into account the possible allergic effects of some of them. The theoretic part of this thesis is focused on aroma compounds and their biological effects. It also describes methods useful for their isolation and analysis with a nearer intent on the methods used in this thesis - solid phase microextraction and gas chromatography. The aim of the experimental part was to establish, optimise and validate the method for determination of allergic aroma compounds chosen and subsequently to enable its using in wide spectrum of food and other products.
|
|
|
Optimalisation of a new micromethod of DNA isolation from foods
Surá, Tereza ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
The thesis were focused on the optimalization of micromethod for isolation of DNA in quality for polymerase chain reaction (PCR) using magnetic microparticles from plant food products. There were chosen a red beetroot (fresh, frozen, dried and sterilized) for the analysis and food products containing red beetroot. Different approaches of processing of homogenates were compared and optimized. The homogenates were prepared in lysis buffer with cetyltrimethylammonium bromide (CTAB) with different amounts of NaCl with or without addition of organic extraction agents chloroform-octanol and isopropanol. Microisolation of DNA was performed using magnetic particles P(GMA). The concentration of NaCl and polyethylene glycol (PEG) 6000 in separation mixtures was tested. The influence on quantity and purity of isolated DNA was compared and the optimum amounts of NaCl in CTAB buffer and optimal concentration of PEG 6000 in separation mixtures were compared. The optimized separation mixture for the DNA isolation from red beetroot was applied to food products containing red beetroot. Amplifiability of DNA was tested in conventional PCR using specific primers for plant DNA. PCR products of length 700 bp were detected by agarose gel electrophoresis.
|
|
| |
|
| |
|
|
Analysis of pesticides in the environment using the QuEChERS method
Vašinková, Alena ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This thesis focuses on pesticides in the environment, more specifically in cereals. Pesticides were monitored in various samples of cereals (barley, rye, oats, and wheat) within the thesis. The monitored substances were isolated in selected samples and concentrated using the QUECHERS method. Gas and liquid chromatography were used to determine pesticides. The theoretical part consists of the common types of pesticides, divided by the ease with which these substances into food and their impact on humans and environment. It also mentions current health protection legislation and environmental legislation.
|
guest ::
