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Analysis of autenthicity of food products with fruit component
Prachárová, Adriana ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The aim of this thesis was to determine the authenticity of fruit food for infants using molecular and instrumental methods. In the experimental part, plant DNA isolations from fruit leaves (peaches, apricots, plums and apples) and bananas were performed. Further, DNA was isolated also from five commercial products, and from model mixtures that were prepared in terms of content identical to the commercial mixtures. The isolated DNA was characterized and verified by qPCR with plant DNA-specific ITS2 primers. Three triple primer pairs were selected, and their specificity was evaluated when performing multiplex PCR. This method makes it possible to detect more types of fruit in one reaction, reducing the economic and time requirements for detection. As none of the selected primer pairs were sufficiently specific for the apricot, the evidence from the plum and peach was further realized using duplex PCR. High resolution melting curve analysis was used for better DNA type recognition. Subsequently, agarose gel electrophoresis was performed to analyse the fragment lengths. Furthermore, experiments have been made to identify some specific phenolic substances in commercial and model fruit mixtures by HPLC. Since phenolic substances are degradable under unsuitable storage conditions, the presence of individual compounds was not detected by this method.
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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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|
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Analysis of autenthicity of food products with fruit component
Prachárová, Adriana ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The aim of this thesis was to determine the authenticity of fruit food for infants using molecular and instrumental methods. In the experimental part, plant DNA isolations from fruit leaves (peaches, apricots, plums and apples) and bananas were performed. Further, DNA was isolated also from five commercial products, and from model mixtures that were prepared in terms of content identical to the commercial mixtures. The isolated DNA was characterized and verified by qPCR with plant DNA-specific ITS2 primers. Three triple primer pairs were selected, and their specificity was evaluated when performing multiplex PCR. This method makes it possible to detect more types of fruit in one reaction, reducing the economic and time requirements for detection. As none of the selected primer pairs were sufficiently specific for the apricot, the evidence from the plum and peach was further realized using duplex PCR. High resolution melting curve analysis was used for better DNA type recognition. Subsequently, agarose gel electrophoresis was performed to analyse the fragment lengths. Furthermore, experiments have been made to identify some specific phenolic substances in commercial and model fruit mixtures by HPLC. Since phenolic substances are degradable under unsuitable storage conditions, the presence of individual compounds was not detected by this method.
|
|
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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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