In the present dissertation thesis quality of plum cultivars were investigated in three successive experiments included measurement of ethylene, CO2, ethanol, acetaldehyde, firmness of the fruits and determination of volatile aromatic compounds by SPME/GC/MS Two plum fruit varieties (Stanley and Valjevka) were stored in prepared gas mixtures (FAN: 0,6 % O2 a 1 % CO2, CA: 1 % O2 a 10 % CO2, RA: 21% O2 a 0,03 % CO2) for 70 days. In terms of the 20th, 40th and 60th day followed shelf life for 10 days at 20 °C. Firmness of the skin was different for both varieties and the softening increased in the variety Valjevka. Softening of fruits significantly decreased in FAN and CA. Skin firmness of fruits stored in normal oxygen atmosphere was lower for about 0,59 MPa (Stanley) and 0,67 MPa (Valjevka) at the end of storage. Fruits stored in CA atmosphere were firm, with unbrowning flesh and there was no browning in stem area, too. The results showed that the variety 'Valjevka' has a high capacity (1705 mg/l) to produce ethanol.There was no microbial damage in 'Stanley' stored in CA and FAN at the end of the storage, in RA were 13,19 %. The highest microbial attack was observed in Valjevka stored in RA 41,85 %. Seventy-one volatile compounds were sampled by head space SPME in two plum fruit varieties (Stanley and Valjevka). Using PCA analysis 13 compounds are sufficient for distinguishing ripening of fruits variety Stanley treated by tree storage atmospheres ((Z)-hex-3-en-1-ol, 2-methyl butan-1-ol, (Z)-3-octen-1-ol, 2-heptanol, heptanal, (Z)-3-hexenal, (E)-2-decenal, n-octanal, ethyl acetate, (E)-2-hexenyl acetate, a-terpineol, b-cyclocitral, b-ionone) and 11 compounds for 'Valjevka' (2-octanol, n-octanal, (E)-2-hexenyl acetate, b-cyclocitral, b-ionone, (Z)-3-octen-1-ol, 2-methyl-1-pentanol, (Z)-3-hexenal, n-hexanal, ethyl benzoate a butyl 2-methylbutyrate). The fruits of 13 plum cultivars were analysed at two different stages of maturity: first when they were ready for picking according to conventional commercial criteria, and again after seven days of maturation during shelf life. In the period of over-ripening SSC increased, and no differences were found in relation to the cultivar. The fruits in this period were physiologically in a phase of reduced intensity of respiration, while production of ethylene increased and was associated with the earliness of the cultivar. Cultivars with a short vegetation period produce more ethylene while late-maturing cultivars have a low potential for ethylene production. Based on post-harvest changes in the tested quality factors, the late-ripening plum cultivars (cv.) Jojo, Topend, President, Tophit and Elena have higher storage potential. A high significant negative correlation was detected between levels of skin firmness and ethylene production. 69 of volatiles were determined by GC/MS/SPME. There are eight compounds (oct-1-en-3-ol, p-menth-1-en-4-ol-R, n-hexan-1-ol, n-pentan-1-ol, ethylhexan-1-ol, g-nonanolaktone, g-kaprolaktone and g-oktalaktone) which taken together can be used to distinguished the two different stages of maturity. The fruits of cv. 'Tophit' were untreated or treated with 1-MCP for 24 h at 20 °C and then kept at 1 °C for 50 days in the atmosphere CA (2 % O2 a 7 % CO2) and RA. Plums were evaluated after 10, 30, 50 days of storage at 1 °C followed by shelf life storage for 7 days. The effect of cold and 1-MCP treatment resulted in significant inhibition of ethylene production, respiration rate and retention of flesh firmness after transfer to room temperature. Sixty-four volatile compounds were sampled by head space SPME and identified by GC-MS, from which (E)-2-hexenal, (Z)-hex-3-en-1-ol, butyl-2-methylbutyrate and limonen were significant.

No description available.

La qualità delle fave di cacao disponibili in commercio, che rappresentano la principale materia prima per la produzione di cioccolato, dipende da diversi fattori inclusi: il tipo di piantagione, le pratiche agricole ed il processo di post raccolta. Tra queste; fermentazione ed essicazzione sono generalmente considerate le più rilevanti, dal momento in cui, durante queste fasi, vengono formati e fissati i precursori degli aromi del cacao. Inoltre, esse rappresentano un step cruciale durante il quale possono verificarsi contaminazioni da parte dei funghi filamentosi. La fermentazione è caratterizzata da una successione ben definita di lieviti, batteri lattici e batteri acetici, a tal fine, lo scopo del presente lavoro di tesi è stato quello di esplorare e descrivere in modo completo le comunità batteriche e fungine coinvolte nella fermentazione delle fave di cacao e valutare se l’origine geografica ed il metodo di fermentazione potessero influenzare la loro composizione. Per ottenere tali risultati il gene 16s rRNA è stato usato come marker per descrivere la comunità batterica totale mediante High Throughput Sequencing (HTS), dimostrando come tale approccio abbia la capacità di evidenziare la totalità delle comunità batteriche a livello di specie. In un secondo approccio l’Internal Transcribed Spacer 1 (ITS1) ed il dominio D1/D2 della sub unità maggiore dell’RNA ribosomiale (26s rRNA) sono stati selezionati per descrivere la popolazione fungina. I risultati hanno evidenziato come le due regioni abbiano la capacità di descrivere la composizione generale delle popolazioni, sebbene il dominio D1/D2 sia stato in grado di analizzare più nel dettaglio la composizione. Infine gli stessi campioni sottoposti all’analisi mediante HTS sono stati analizzati mediante SPME-GC-MS per evidenziare i principali composti aromatici formatisi durante il processo di post raccolta. Complessivamente i risultati indicano chiaramente che l’approccio mediante HTS ha le potenzialità per fornire una dettagliata visione d’insieme delle comunità batteriche e fungine presenti durante le fasi di post raccolta delle fave di cacao, inoltre le analisi statistiche hanno evidenziato come l’ITS1 ed i composti volatili possano essere utilizzati per la tracciabilità geografica. / The quality of commercial cocoa beans, the principal raw material for chocolate production, depends on several factors including type of plantations, the agricultural practices and the post-harvest processing. Among these, fermentation and drying are generally considered the most relevant, since during these phases cocoa flavors precursors are formed and fixed. Furthermore, they represent crucial steps during which filamentous fungi contamination might occur. Fermentation is characterized by a well-defined succession of yeasts, lactic acid bacteria and acetic acid bacteria, so that, the aim of the described studies was to explore total bacterial and fungal communities involved in cocoa bean fermentation and to evaluate if geographical origin and fermentation method might affect their composition. To achieve these results, 16s rRNA gene was used as marker to assess the total bacterial community by using High Throughput Sequencing (HTS), indicating that this approach has the ability to provide a comprehensive view of the cocoa bean microbiota at the species level. In a second approach, Internal Transcribed Spacer 1 (ITS1) and the D1/D2 domain of the Large subunit (LSU) of the nuclear ribosomal RNA (26S rRNA) were screened to assess the total fungal community. Results revealed the ability of these two genomic regions to describe reliably the general composition, even if D1/D2domain was able to go deeper into the fungal composition resulting in a higher resolution. In the last approach the same samples subjected to HTS investigation were analyzed through SPME-GC-MS in order to underline the principal key-aroma compounds formed during the post-harvest processing. Overall, results point out clearly that HTS approach has the ability to provide a comprehensive view of the total bacterial and fungal communities, and statistical analyses have shown how analyses of ITS1 sequences and volatile compounds might be useful for the geographical traceability of the processed cocoa beans samples.

Le méconium constitue les premières selles du nourrisson. Cette matrice complexe est analysée dans le cadre du projet « PENEW » (Pregnancy Environment and NEWborn malformations) afin de déterminer si le degré d'exposition fœtale aux xénobiotiques joue un rôle dans la survenue de malformations congénitales. Le but de cette étude était le développement analytique pour la détection et la quantification dans le méconium d’une quarantaine de composés de familles différentes (composés organiques volatils, pesticides, éthers de glycol et les métabolites associés). Trois techniques analytiques différentes et une préparation d’échantillon spécifiques ont été développées pour la détection et la quantification de ces composés dans le méconium. L’application des ces méthodes à 246 échantillons de méconium a montré une exposition fœtale à plusieurs des substances recherchées. / Meconium is the earliest stool of newborns. This complex matrix was analyzed through the "PENEW" project (Pregnancy and Newborn malformations Environment) to determine if the degree of fetal exposure to xenobiotics has an influence in the occurrence of birth defects. The objective of this thesis was developed analytical methods for the detection and quantification of several different families of compounds (volatile organic compounds, pesticides, glycol ethers and their metabolites) in meconium. Three different analytical methods and a specific sample preparation have been developed for the detection and quantification of these compounds in the meconium. The application of these methods to 246 meconium samples showed a fetal exposure to several target compounds.

This master's thesis deals with the analysis of biochar extracts by separation methods. All analyzed biochar was produced from waterworks sludge by microwave pyrolysis. The aim of the thesis is the optimization of the sample preparation method and its analysis in a laboratory environment. With the ever-growing world population, the problem of a sustainable economy in both agriculture and waste management is becoming increasingly urgent. This fact has led most countries to consider promoting the so-called Circular Economy. The use of sewage sludge as a feedstock for biochar production is perfectly in line with this strategy. So far, however, the short term and the long term benefits and risks of using biochar have not been sufficiently described. Potentially hazardous organic substances were extracted from the biochar extracts by three techniques: liquid-liquid extraction, solid-phase extraction, and solid- phase micro-extraction. The obtained samples were analyzed using the GS-MS/TOF method. The individual methods were compared. Several biochar samples from WWTP Brno and WWTP Drahovice were selected and analyzed to verify the suitability of the selected sample analysis method.

All-purpose wheat flour is a useful long-term storage commodity, but is subject to off-odor formation. Although flour stored in a low oxygen atmosphere should inhibit rancid odor formation, it elicits consumer complaints about odor. The purpose of this study was to examine off-odor development in all-purpose wheat flour during ambient and elevated storage by determining the effect of low oxygen atmosphere and enrichment-bleaching on quality as measured by, free fatty acids (FFA), flour descriptive sensory analysis, conjugated dienes, headspace volatiles, bread consumer sensory analysis, color, loaf volume, and vitamin analysis. Enriched, bleached (EB) and unenriched, unbleached (UU) flour was stored in a low and normal oxygen atmosphere in no. 10 cans at 22, 30, and 40°C for 24 weeks. Moisture remained constant throughout the study. Headspace oxygen was < 0.1% in flour stored in a low oxygen atmosphere and decreased in flour stored in a normal oxygen atmosphere. FFA increased with storage time and temperature. The "fresh flour" descriptive aroma of flour decreased during storage and decreased more rapidly in a low oxygen atmosphere. The "cardboard/stale" aroma increased in flour stored in a normal oxygen atmosphere. The "acid-metallic" aroma increased in flour stored in a low oxygen atmosphere and was determined to be the off-odor from consumer complaints. Conjugated dienes and volatiles generally increased more rapidly in flour stored in a normal oxygen atmosphere and in EB flour, suggesting that the acid-metallic odor did not result from lipid oxidation. Bread consumer sensory analysis identified EB flour stored in a normal oxygen atmosphere to have the lowest acceptance scores for aroma, overall acceptability, and flavor. The acid-metallic odor dissipated within 24 hours when the container was opened and was not detrimental to consumer acceptance of bread made from the flour. Oxygen absorbers prevented the darkening of flour but not the reddening or yellowing. A low oxygen atmosphere resulted in higher bread loaf volumes. Vitamin degradation is not a concern under normal storage conditions. Bleaching appears to increase flour oxidative rancidity more than enrichment. Although storage at a low oxygen atmosphere results in an off-odor present in newly opened cans, it gave higher quality flour and bread. A low oxygen atmosphere should continue to be used in flour stored long-term, and consumers should be made aware that the off-odor present in cans of flour dissipates after opening.

O Brasil apresenta grande potencial para a exploração da apicultura, dado ao seu vasto território e flora diversificada, o que permite diferentes variedades de méis com propriedades únicas. O estado do Paraná é um dos maiores produtores de méis do país e o investimento em produção que atenda aos mercados mais exigentes estimulou a produção do mel orgânico. O conhecimento desde a antiguidade sobre os efeitos benéficos à saúde pelo mel vem estimulando a pesquisa deste alimento nobre. Assim, este trabalho teve por objetivo estudar méis orgânicos brasileiros certificados (MO) para a caracterização do perfil fenólico, volátil, além da avaliação da capacidade de sequestro das espécies reativas de oxigênio e nitrogênio. Os méis foram coletados nos apiários de apicultores com certificação orgânica de dois municípios do sul do Paraná, General Carneiro e Turvo-PR. Nos ensaios foram utilizados extratos fenólicos dos méis, obtidos por meio da utilização da resina Amberlite® XAD®2, bem como méis brutos in natura. Os extratos apresentaram conteúdo de compostos fenólicos significativo, sendo o melato (MO5), de General Carneiro, o de maior teor (117,68± 4,40 mg EAG/g). Para as análises de sequestro das espécies reativas de oxigênio e nitrogênio, os extratos fenólicos foram sempre superiores aos méis brutos in natura. Os extratos fenólicos, de maneira geral, apresentaram alta capacidade de sequestro para o radical peroxila (ROOo), ácido hipocloroso (HOCl) e óxido nítrico (NOo). Em relação aos melatos, o extrato MO7 apresentou alta capacidade para o sequestro do HOCl (EC50= 4,83 ± 0,13 ?g/mL), enquanto que o MO5 foi melhor para o sequestro do NOo (EC50=2,16 ± 0,18 ?g/mL). Pelo método HPLC-ABTS on-line foi possível identificar e quantificar a contribuição para a atividade antioxidante do ácido ferúlico no extrato (MO1) e do flavonoide kanferol na amostra (MO4). O ácido ascórbico foi identificado e quantificado por HPLC somente nos melatos (MO3, MO5 e MO7). Pela técnica de LC-MS/MS foram identificados a presença dos seguintes compostos fenólicos: ácido caféico, rutina e hesperidina em todos os extratos. A análise de compostos voláteis por SPME-CG/EM mostrou a presença de dois compostos, encontrados apenas nos melatos, que foram o terpineno-4-ol, que possui ação antifúngica, antiparasitológica e anti-inflamatória; e o 3,4-dimetil-1-deceno, podendo assim serem utilizados como marcadores químicos destes méis. O conhecimento da composição química destes méis, bem como a composição fenólica bioativa, contribui para o fornecimento de antioxidantes naturais para a dieta, atenuando assim os efeitos negativos dos radicais livres / Brazil has a great potential to explore beekeeping due to its vast territory and diversified flora, what allows different varieties of honeys with unique characteristics. Parana state is one of the largest honey producers and the investment in production that meets the most demanding markets stimulated the organic honey production. The knowledge since early in history regarding the beneficial health effects promoted by honey is stimulating the scientific research of this noble food. Thus, this paper aimed to study certified Brazilian organic honeys (MO) in order to determine the phenolic and volatile profiles, and also the evaluation of radical scavenging capacity against Nitrogen and Oxygen Reactive Species (RNS and ROS, respectively). The honeys were collected from apiaries from beekeepers with the organic certification from two municipalities of southern Parana, General Carneiro and Turvo, PR. In the essays, phenolic extracts were obtained from honeys by using Amberlite® XAD®2 resin, as well as crude in natura honeys. The extracts showed a significant content in phenolic compounds, with honeydew (MO5), from General Carneiro, showing the highest content (117,68 ± 4,40 mg AGE/g). For the analyzes to determine the radical scavenging capacity against RNS and ROS, the phenolic extracts always showed up superior results in comparison to crude in natura honeys. Phenolic extracts showed, in general, great capacity to scavenge peroxyl radical (ROOo), hypochlorous acid (HOCl) and nitric oxide (NOo). In relation to honeydews MO7 extract showed the highest capacity to scavenge HOCl (IC50= 4,83 ± 0,13 ?g/mL) while MO5 was the sample with better capacity to scavenge NOo (IC50=2,16 ± 0,18 ?g/mL). By using HPLC-ABTS on-line method it was possible to identify and to quantify the ferulic acid in MO1 extract, a compound with an important contribution to the antioxidant activity of this sample, as well as the flavonoid kaempferol in MO4 sample. Ascorbic acid was identified and quantified by HPLC only in the honeydew samples (MO3, MO5 and MO7). The analyzes developed by LC-MS/MS techniques indicated the presence of the phenolic compounds caffeic acid, rutin and hesperidin in all the extracts. The analysis of volatile substances developed by SPME-GC/MS promoted the identification of two compounds found only in the honeydew samples. The compounds were the terpinen-4-ol, which has antifungal, antiparasitological and anti-inflammatory activities; and 3,4-dimethyl-1-decene. Both compounds can be used as chemical markers of these honeys. The knowledge of the chemical composition of the studied honeys, as well as their bioactive phenolic composition, contributes to supply natural antioxidants to human diet, thus attenuating the negative effects of free radicals

O Brasil apresenta grande potencial para a exploração da apicultura, dado ao seu vasto território e flora diversificada, o que permite diferentes variedades de méis com propriedades únicas. O estado do Paraná é um dos maiores produtores de méis do país e o investimento em produção que atenda aos mercados mais exigentes estimulou a produção do mel orgânico. O conhecimento desde a antiguidade sobre os efeitos benéficos à saúde pelo mel vem estimulando a pesquisa deste alimento nobre. Assim, este trabalho teve por objetivo estudar méis orgânicos brasileiros certificados (MO) para a caracterização do perfil fenólico, volátil, além da avaliação da capacidade de sequestro das espécies reativas de oxigênio e nitrogênio. Os méis foram coletados nos apiários de apicultores com certificação orgânica de dois municípios do sul do Paraná, General Carneiro e Turvo-PR. Nos ensaios foram utilizados extratos fenólicos dos méis, obtidos por meio da utilização da resina Amberlite® XAD®2, bem como méis brutos in natura. Os extratos apresentaram conteúdo de compostos fenólicos significativo, sendo o melato (MO5), de General Carneiro, o de maior teor (117,68± 4,40 mg EAG/g). Para as análises de sequestro das espécies reativas de oxigênio e nitrogênio, os extratos fenólicos foram sempre superiores aos méis brutos in natura. Os extratos fenólicos, de maneira geral, apresentaram alta capacidade de sequestro para o radical peroxila (ROOo), ácido hipocloroso (HOCl) e óxido nítrico (NOo). Em relação aos melatos, o extrato MO7 apresentou alta capacidade para o sequestro do HOCl (EC50= 4,83 ± 0,13 ?g/mL), enquanto que o MO5 foi melhor para o sequestro do NOo (EC50=2,16 ± 0,18 ?g/mL). Pelo método HPLC-ABTS on-line foi possível identificar e quantificar a contribuição para a atividade antioxidante do ácido ferúlico no extrato (MO1) e do flavonoide kanferol na amostra (MO4). O ácido ascórbico foi identificado e quantificado por HPLC somente nos melatos (MO3, MO5 e MO7). Pela técnica de LC-MS/MS foram identificados a presença dos seguintes compostos fenólicos: ácido caféico, rutina e hesperidina em todos os extratos. A análise de compostos voláteis por SPME-CG/EM mostrou a presença de dois compostos, encontrados apenas nos melatos, que foram o terpineno-4-ol, que possui ação antifúngica, antiparasitológica e anti-inflamatória; e o 3,4-dimetil-1-deceno, podendo assim serem utilizados como marcadores químicos destes méis. O conhecimento da composição química destes méis, bem como a composição fenólica bioativa, contribui para o fornecimento de antioxidantes naturais para a dieta, atenuando assim os efeitos negativos dos radicais livres / Brazil has a great potential to explore beekeeping due to its vast territory and diversified flora, what allows different varieties of honeys with unique characteristics. Parana state is one of the largest honey producers and the investment in production that meets the most demanding markets stimulated the organic honey production. The knowledge since early in history regarding the beneficial health effects promoted by honey is stimulating the scientific research of this noble food. Thus, this paper aimed to study certified Brazilian organic honeys (MO) in order to determine the phenolic and volatile profiles, and also the evaluation of radical scavenging capacity against Nitrogen and Oxygen Reactive Species (RNS and ROS, respectively). The honeys were collected from apiaries from beekeepers with the organic certification from two municipalities of southern Parana, General Carneiro and Turvo, PR. In the essays, phenolic extracts were obtained from honeys by using Amberlite® XAD®2 resin, as well as crude in natura honeys. The extracts showed a significant content in phenolic compounds, with honeydew (MO5), from General Carneiro, showing the highest content (117,68 ± 4,40 mg AGE/g). For the analyzes to determine the radical scavenging capacity against RNS and ROS, the phenolic extracts always showed up superior results in comparison to crude in natura honeys. Phenolic extracts showed, in general, great capacity to scavenge peroxyl radical (ROOo), hypochlorous acid (HOCl) and nitric oxide (NOo). In relation to honeydews MO7 extract showed the highest capacity to scavenge HOCl (IC50= 4,83 ± 0,13 ?g/mL) while MO5 was the sample with better capacity to scavenge NOo (IC50=2,16 ± 0,18 ?g/mL). By using HPLC-ABTS on-line method it was possible to identify and to quantify the ferulic acid in MO1 extract, a compound with an important contribution to the antioxidant activity of this sample, as well as the flavonoid kaempferol in MO4 sample. Ascorbic acid was identified and quantified by HPLC only in the honeydew samples (MO3, MO5 and MO7). The analyzes developed by LC-MS/MS techniques indicated the presence of the phenolic compounds caffeic acid, rutin and hesperidin in all the extracts. The analysis of volatile substances developed by SPME-GC/MS promoted the identification of two compounds found only in the honeydew samples. The compounds were the terpinen-4-ol, which has antifungal, antiparasitological and anti-inflammatory activities; and 3,4-dimethyl-1-decene. Both compounds can be used as chemical markers of these honeys. The knowledge of the chemical composition of the studied honeys, as well as their bioactive phenolic composition, contributes to supply natural antioxidants to human diet, thus attenuating the negative effects of free radicals