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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.
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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.
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Determination of selected red fruit species in plant-based food using multiplex PCR and instrumental methods
Vybíralová, Natálie ; Langová, Denisa (referee) ; Fialová, Lenka (advisor)
In many cases food is becoming the subject of adulteration, including fruit products that contain raspberries, strawberries and blueberries. This bachelor thesis is focused on the detection of strawberries, rapsberries and blueberries in model and commercial baby food products using multiplex PCR and HLPC. The theoretical part of this thesis is focused on composition of red fruits, their importance in human nutrition and especially about isolation of DNA from plant material. The aim of the experimental part of work was the analysis of selected commercial and model mixtures fruit purees containg raspeberries, strawberries and blueberries using instrumental and molecular biological methods. The results of these metods are compared. Commercial purees were bought in retail grocery shop. Model mixtures of these purees were prepared in our laboratory. DNA was isolated from fruit purees after and it’s amplifiability was comfirmed, it was successfully used in multiplex PCR to confirm the presence of raspberries, strawberries and blueberries in fruit purees. In the instrumental part, certain phenolic substences which are specific to red fruits were detected by HPLC in model and commercial mixtures.
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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.
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Determination of selected red fruit species in plant-based food using multiplex PCR and instrumental methods
Vybíralová, Natálie ; Langová, Denisa (referee) ; Fialová, Lenka (advisor)
In many cases food is becoming the subject of adulteration, including fruit products that contain raspberries, strawberries and blueberries. This bachelor thesis is focused on the detection of strawberries, rapsberries and blueberries in model and commercial baby food products using multiplex PCR and HLPC. The theoretical part of this thesis is focused on composition of red fruits, their importance in human nutrition and especially about isolation of DNA from plant material. The aim of the experimental part of work was the analysis of selected commercial and model mixtures fruit purees containg raspeberries, strawberries and blueberries using instrumental and molecular biological methods. The results of these metods are compared. Commercial purees were bought in retail grocery shop. Model mixtures of these purees were prepared in our laboratory. DNA was isolated from fruit purees after and it’s amplifiability was comfirmed, it was successfully used in multiplex PCR to confirm the presence of raspberries, strawberries and blueberries in fruit purees. In the instrumental part, certain phenolic substences which are specific to red fruits were detected by HPLC in model and commercial mixtures.
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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.
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Authenticity of food on the Czech market
LÍBALOVÁ, Renata
The Thesis acquaints consumers with Czech and European legislation regarding food quality and safety. There are also described in detail the supervisory autorities for food authenticity operating in Czech Republic and related terms such as food quality and safety. The following is a pivotal part dedicated to the food authenticity, which describes the problem of food adulteration, including the reasons and methods of food adulteration. The practical part contains the results of inspections of food by SZPI for the year 2015. The analysis of the data is based on the website "Potraviny na pranýři". Another part relates to the evaluation of questionnaire, which focuses on consumers's relationship to authenticity and adulteration of food on the Czech market. The practical part is concludes by the evaluation of set hypotheses.
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