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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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Study of the authenticity of spices and condiments
Štursa, Václav ; Golian, Jozef (referee) ; Urík, Martin (referee) ; Diviš, Pavel (advisor)
This disertation deals with geographical authentification of different types of spices and spice preparations. Investigated spice species were garlic (Allium sativum), ground pepper (Capsicum anuum), and dried carrot (Daucus carota). Theoretical part of the disertation describes main qualitative parameters of the examined species and production technology, means of food adulteration and statistic methods used in chemometrics. The aim of this dissertation was to verify the hypothesis whether it is possible to use targeted analytical techniques commonly used in quality control of spices and condiments, and statistical processing of measured data to distinguish samples of spices and condiments of different geographical origin. The use of non-targeted analysis was also investigated. Samples of garlic and ground pepper were used for targeted analysis. The examined parameters were dry matter and moisture of the sample, ash content, total phenolic content according to Folin-Ciocaulteu, carbohydrate content, alliin concentration, total nitrogen content, total color pigment (ASTA), pH of aqueous extract, total fat content, and concentration of selected elements (Ca, Cu, Fe, K, Mn, Mg, Na, P, Zn). The instrumental techniques used were molecular absorption spectrometry, inductively coupled plasma optical emission spectrometry and high performance liquid chromatography. The obtained data were statistically processed by analysis of variance (ANOVA) and principal component analysis (PCA). Using statistical analysis significant differences between samples that came from more distant areas were found. However, samples from closer areas could not be distinguished. The researched hypothesis could not be unequivocally confirmed or refuted. Metabolic fingerprint of carrot samples was determined using non-targeted analysis. Metabolic analysis was performed using the tandem LC-TOF-MS technique. The data were processed by recursive peak extraction (BRE) and subsequently uvaluated with PCA. The samples were divided into clusters according to their origin. Targeted and non-targeted techniques have great potential in verifying the geographical authenticity of different types of spices. However, the main condition is consistent and sufficient sampling, guaranteed information on the origin of the sample and obtaining a sufficient amount of input data for statistical analysis.
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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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Study of the authenticity of spices and condiments
Štursa, Václav ; Golian, Jozef (referee) ; Urík, Martin (referee) ; Diviš, Pavel (advisor)
This disertation deals with geographical authentification of different types of spices and spice preparations. Investigated spice species were garlic (Allium sativum), ground pepper (Capsicum anuum), and dried carrot (Daucus carota). Theoretical part of the disertation describes main qualitative parameters of the examined species and production technology, means of food adulteration and statistic methods used in chemometrics. The aim of this dissertation was to verify the hypothesis whether it is possible to use targeted analytical techniques commonly used in quality control of spices and condiments, and statistical processing of measured data to distinguish samples of spices and condiments of different geographical origin. The use of non-targeted analysis was also investigated. Samples of garlic and ground pepper were used for targeted analysis. The examined parameters were dry matter and moisture of the sample, ash content, total phenolic content according to Folin-Ciocaulteu, carbohydrate content, alliin concentration, total nitrogen content, total color pigment (ASTA), pH of aqueous extract, total fat content, and concentration of selected elements (Ca, Cu, Fe, K, Mn, Mg, Na, P, Zn). The instrumental techniques used were molecular absorption spectrometry, inductively coupled plasma optical emission spectrometry and high performance liquid chromatography. The obtained data were statistically processed by analysis of variance (ANOVA) and principal component analysis (PCA). Using statistical analysis significant differences between samples that came from more distant areas were found. However, samples from closer areas could not be distinguished. The researched hypothesis could not be unequivocally confirmed or refuted. Metabolic fingerprint of carrot samples was determined using non-targeted analysis. Metabolic analysis was performed using the tandem LC-TOF-MS technique. The data were processed by recursive peak extraction (BRE) and subsequently uvaluated with PCA. The samples were divided into clusters according to their origin. Targeted and non-targeted techniques have great potential in verifying the geographical authenticity of different types of spices. However, the main condition is consistent and sufficient sampling, guaranteed information on the origin of the sample and obtaining a sufficient amount of input data for statistical analysis.
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