The aim of the work was identification of aroma active compounds in Moravský bochník cheese type, than discuss their changes during ripening and consider influence of aplication different rates of microbial cultures on number of volatile compounds. SPME-GC-MS was used for identification of volatile compounds. In total, 148 of volatile compounds were identified and 82 of them are considered as aroma active compounds. Three microbial cultures (their combination with predominant thermophilic or mesophilic culture) were used for making samples. The influence of predominant thermophilic/mesophilic culture on number of volatile compounds was not proved. From the point of view of sensory quality, combinations with predominant mesophilic culture proved to be more successful. During ripening, the number of identified compounds was reduced in all the combinations of cultures studied. The optimal time for ripening seems to be three months.

The diploma thesis will be focuses on the isolation of fragrances of natural origin by steam vapor distillation, ultrasonic extraction, microwave extraction and pressure solvent extraction. The extracts were characterized by GCxGC/TOF-MS. To study the surface structure of the leaf by SEM, a sample of the medulla medical was selected. Photos were taken before and after extraction.

No description available.

6 Abstract This thesis focuses on the identification and quantification of volatile metabolites in the exhaled breath that might be used as possible biomarkers of Gastroesophageal Reflux Disease. Animal tissue samples were exposed to conditions simulating the gastric environment to identify specific volatile compounds that would be chosen for real-time quantification in exhaled breath of GERD patients and healthy controls using selected ion flow tube mass spectrometry. Solid phase microextraction, was used in combination with gas chromatography mass spectrometry, for qualitative analyses of the headspace of these samples. Only acetic acid was significantly elevated and so it has been elected for the quantitative analysis in the breath of the patients. The median concentration of acetic acid measured by SIFT-MS in the exhaled breath of twenty-two GERD patients was found to be higher (85 ppbv) in comparison to the control group (31 ppbv). The results show that breath acetic acid could be valuable marker for GERD diagnosis and monitoring.

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.

D-γ-tocotrienol (G-T3) chiefly present in palm oil has stolen the spotlight as a promising radiation protective agent for the treatment of acute radiation syndrome (ARS). Although G-T3 is a promising counteracting agent discovered, the separation and purification from its matrix are painstaking. These have limited its characterization, derivatization, and biomedical application. In this study, we developed chromatographic and distillation methods to enhance the purity and synthesis of G-T3 derivatives. Exactly 8% ethyl acetate (EA) in hexanes used in TLC resulted in right spots separation. Two gradient column chromatographic methods were examined using solvent mixtures of EA/hexanes and EA/petroleum ether (PE), respectively. We verified that a gradient elution with EA in PE led to the maximum purity (≥95%) based on the NMR and GC-MS outcomes. Also, G-T3 was stable in an emulsion to some extent, and some soluble G-T3 derivatives were synthesized, and their structure was confirmed

No description available.

NR 20140805

Allt eftersom problemen med fossila ämnen blir mer tydliga dras industrins uppmärksamhet till trä som en förnybar råvara och energikälla. I Sverige finns stora resurser av barrträd, vilket har betytt mycket för landets ekonomi och kommer förmodligen att göra det i framtiden också. Ett stort problem vid nyplantering av barrträd är dock angrepp av skadeinsekter, som kan leda till att så mycket som 40 % av trädplantorna dör inom ett år. Nyligen har ett ämne som förekommer i barrträd, metyljasmonat, uppmärksammats för sina skyddande effekter. Då det är naturligt och helt bionedbrytbart har det föreslagits som ett miljövänligt alternativ till traditionella pesticider. För kommersialisering och vidare utveckling bör dock ämnets påverkan på trädet undersökas.  Vi undersökte sammansättningen av aminosyror i barken hos behandlade och obehandlade plantor med kapillärelektrofores. Metoden som användes visade sig dock ha dålig reproducerbarhet, vilket gjorde resultaten opålitliga. De tydde på att metyljasmonatbehandlingen inte ändrade sammansättningen dramatiskt, men det krävs en mer robust metod för att dra säkra slutsatser. Vi undersökte även förekomst och mängd av terpener i barkproverna med GC-MS. Fem stycken terpener karakteriserades: 3-karen, D-limonen, β-fellandren, geranyl linalool och thunbergol. Metoden visade god reproducerbarhet och tillförlitlighet, men mer data behövdes för att kunna dra slutsatser med statistisk säkerhet. Samtliga prover visade sig innehålla mätbara halter av 3-karen, β-fellandren och thunbergol. Resultaten antyder att koncentrationen av terpener överlag ökade efter metyljasmonatbehandling och detta var särskilt tydligt för β-fellandren. Det fanns anledning att tro att genetiska faktorer påverkade resultatet av behandlingen, då vissa kloner svarade starkare på behandlingen än andra.

No description available.