|
|
Testing of primers for real-time PCR-HRM analysis of fruit products containing one fruit species
Boháčová, Barbora ; Dzurendová, Simona (referee) ; Fialová, Lenka (advisor)
Determining the authenticity of fruit products, which are often counterfeited by substituting part of a more expensive fruit with a cheaper but botanically similar fruit, is a current topic in the food industry. A prime example is the dilution of apricot products with peach puree. This study focuses on testing specific primers AGS18 and PdCass to reveal the true proportion of apricot content in model products mixed with peach puree using PCR analysis followed by HRM analysis. Testing of these primers for authenticity determination revealed limited utility of AGS18 primers due to the formation of small amount or no specific products during reactions with fruit DNA. PdCass primers required PCR condition optimization, but subsequently, specific DNA sequences from fruit leaves could be amplified in sufficient quantities. PCR analysis of DNA from model products with PdCass primers provided specific products in samples with apricot content of 70% or less. HRM analysis of samples and calculation of GCP did not distinguish purees with 0%, 10%, and 30% apricot content. However, purees with 50% and 70% apricot content exhibited significantly different melting curves compared to other samples.
|
|
|
Determination of athenticity of plant foods by molecular techniques
Plášková, Anna ; Mikulíková, Renata (referee) ; Němcová, Andrea (advisor)
The aim of presented diploma thesis was to determination of authenticity of fruit baby foods for early infant feeding using molecular methods. In the experimental part, isolation kit was used for isolation of plant DNA from fruits (strawberry, apricot, raspberry, apple) and from six commercial fruit products for children. Isolated DNA was characterized and verified using PCR methods with primers specific for plant rDNA (ITS2). Specific primer pairs were designed to amplify DNA for the detection of one fruit species. Primer specificity was assessed with four fruit species. A mixture of fruit puree from the two fruits was used to determine the sensitivity of the multiplex PCR assay. Six commercial fruit products were evaluated to verify the applicability of the multiplex PCR assay. The methodology of molecular detection of fruit DNA by qPCR and multiplex qPCR (duplex) includes approaches, which enable to detect two fruits (strawberry-raspberry, apricot-apple) in one reaction and thus reduces time and money requirements.
|
|
|
Analysis of authenticity of some food products with fruit component by molecular and instrumental techniques
Pecháček, Michal ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This master’s thesis was focused on determining the authenticity of some food products with fruit component by molecular and instrumental techniques. The thesis was divided into theoretical and practical part. The theoretical part of the work was focused on food adulteration, methods of determining the food authenticity, analysed types or technologies of production of individual food products, which were analysed in this work. This part was also focused on molecular and instrumental techniques, which are currently used to determine the food authenticity. The practical part of the thesis was divided into molecular and instrumental part. Within the molecular part, DNA isolation was performed using the EliGene Plant DNA Isolation kit. Inhibitors such as polysaccharides seemed to be the biggest problem during the DNA isolation. Therefore, an isolation method using pectinase incubation was performed. The isolated DNA was subsequently subjected to PCR and the resulting PCR products were analysed by a melting curve analysis. This method was used for ITS2 primers, which were used for the plant DNA detection. In the case of species-specific primers BAS1 and Pa3LTP that were used for the peach and apricot detection, high resolution melting (HRM) analysis was performed. During HRM, the focus was on the melting temperature of the specific PCR products. The melting temperature of the BAS1 specific product was set at 78,4 °C and at 86,43 °C for the specific product of Pa3LTP primers. Finally, specific PCR products were subjected to agarose gel electrophoresis. In the case of ITS2 primers, which served to verify the amplifiability of plant DNA, a band of 500 bp was detected. In the case of species-specific primers BAS1 and Pa3LTP, bands from 100 to 150 bp were detected. In the instrumental part of this thesis the HPLC/PDA analysis of the phenolic compounds was performed. The most suitable procedure for the analysis of phenolic substances was the purification procedure using ethanol without further concentration At the end of the work, the individual methods were compared with each other. At the same time, the influence of the matrix on the overall determination of food authenticity was monitored. While molecular techniques could be used to determine the food authenticity by determining the presence of specific DNA, instrumental techniques would be more suitable for detecting food adulteration and detecting specific substances.
|
|
|
Hodnotenie odrôd marhúľ při dozrievaní na strome
Baričič, Michal
The theme of the thesis was to evaluate the varieties of apricots (Prunus armeniaca) ripened on the tree. Following three varieties of apricots have been evaluated: 'Leskora', 'Betinka' and 'Marlen', following quality criteria of the fruit have been monitored: skin firmness, soluble solids content in the fruit and titratable acidity. Monitoring has been performed in three stages of maturity and repeated after seven days storage at 20 ° C. The results of individual observations were evaluated by maturity index. Changes of the organoleptic parameters we monitored after the harvest, and repeated after seven days storage at 20 °C. We assessed firmness and taste of the fruit pulp. The objective pursued was to assess the suitability of selected varieties for storage by keeping the desired sensoric parameters. Based on the results, we can recommend as the most suitable for the storage harvesting stage - green harvesting. According to the index of maturity and organoleptic characteristics showed the best results variety 'Betinka' - unripe fruits, in all evaluated criteria after seven days storing in temperature 20 °C.
|
|
| |
|
| |
|
|
Vliv zralosti ovoce na kvalitu kompotů
Hrazdírová, Barbora
In this thesis was described the sort of fruit, its material composition, the processing of canning and health risks associated with using materials of poor quality. The practical experiment was made with two varieties of apricots (Leskora, Tomcot) which were harvested at three different stages of maturity. The fresh fruit was determined by the weight of the cores and the fruit, width, height and the thickness of the fruit,the shape index, the proportion of core, color, penetrometric stress, the content of organic acids and the content of soluble solids. Apricot compotes, which were made from fruits, were analyzed by the sensorial evaluation. There was the evaluation by the color, appearance, aroma, texture, taste and general impression. The compotes were laboratory determined by soluble solids content and organic acid content again. There was found the type Tomcot preserves even after the cann processing its solid consistency and is suitable for producing apricot compotes.
|
|
| |
|
|
Cultivation of stone fruits in the conditions of occurrence of the causal agents of cork necrosis and premature death of apricots and peaches in production orchards
Pánková, Iveta ; Krejzar, Václav ; Krejzarová, Radka
The methodology monitors the vegetation season in the orchards of stone fruits with regard to the possible influence of performed agrotechnical measurements on the occurrence of the pests, especially bacterial causal agents from the complex Pseudomonas syringae (Ps), Ps. pv. syringae and Ps. pv. morsprunorum races 1. and 3. Regulation of bacterial pathogens is becoming increasingly difficult due to the current possibilities of fruit tree protection, the range of cultivated genotypes and the complex life cycle of pathogens. Manifestations of the disease vary in individual growing seasons depending on the weather. However, the effects and severity of the disease are cumulative. Caring for the health of the tree begins with the production of nursery sprouts and must continue throughout the life of the tree. The methodology describes the individual standard agrotechnical measurements in production orchards in the context of the pathogen life cycle. Based on the results of the project, possible labor and economically acceptable modifications of agricultural practices including timing are proposed in order to reduce the inoculum of cork necrosis agents and reduce economic losses due to premature death of apricot trees.
Fulltext:  PDF
|
|
|
Analysis of authenticity of some food products with fruit component by molecular and instrumental techniques
Pecháček, Michal ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
This master’s thesis was focused on determining the authenticity of some food products with fruit component by molecular and instrumental techniques. The thesis was divided into theoretical and practical part. The theoretical part of the work was focused on food adulteration, methods of determining the food authenticity, analysed types or technologies of production of individual food products, which were analysed in this work. This part was also focused on molecular and instrumental techniques, which are currently used to determine the food authenticity. The practical part of the thesis was divided into molecular and instrumental part. Within the molecular part, DNA isolation was performed using the EliGene Plant DNA Isolation kit. Inhibitors such as polysaccharides seemed to be the biggest problem during the DNA isolation. Therefore, an isolation method using pectinase incubation was performed. The isolated DNA was subsequently subjected to PCR and the resulting PCR products were analysed by a melting curve analysis. This method was used for ITS2 primers, which were used for the plant DNA detection. In the case of species-specific primers BAS1 and Pa3LTP that were used for the peach and apricot detection, high resolution melting (HRM) analysis was performed. During HRM, the focus was on the melting temperature of the specific PCR products. The melting temperature of the BAS1 specific product was set at 78,4 °C and at 86,43 °C for the specific product of Pa3LTP primers. Finally, specific PCR products were subjected to agarose gel electrophoresis. In the case of ITS2 primers, which served to verify the amplifiability of plant DNA, a band of 500 bp was detected. In the case of species-specific primers BAS1 and Pa3LTP, bands from 100 to 150 bp were detected. In the instrumental part of this thesis the HPLC/PDA analysis of the phenolic compounds was performed. The most suitable procedure for the analysis of phenolic substances was the purification procedure using ethanol without further concentration At the end of the work, the individual methods were compared with each other. At the same time, the influence of the matrix on the overall determination of food authenticity was monitored. While molecular techniques could be used to determine the food authenticity by determining the presence of specific DNA, instrumental techniques would be more suitable for detecting food adulteration and detecting specific substances.
|
guest ::
