In this diploma thesis I dealt with developing of separation technique LC-MS for determination of thaumatin. I dealt with isolation and determination of thaumatin in model food sample.

Das Ziel dieser Arbeit ist es biobasierte, bioabbaubare Biokunststoffe mit einfacher Prozesstechnik zu desintegrieren und für anaerobe Mikroorganismen verfügbar zu machen. Mittels der Ergebnisse der Untersuchungen soll nachgewiesen werden, dass eine anaerobe Verwertung der desintegrierten Biokunststoffe bzw. der generierten Flüssigkeiten möglich ist. Außerdem soll ermittelt werden, welches energetische Potenzial dabei freigesetzt wird. Im Rahmen einer Wirtschaftlichkeitsbetrachtung wird die Implementierung einer Desintegrationsstufe in einer Vergärungsanlage bewertet. Zu Beginn der Untersuchungen wird festgestellt, dass eine anaerobe Verwertung im mesophilen und im thermophilen Bereich nur unzureichend realisierbar ist. In den anschließenden Untersuchungen werden Maßnahmen zur Beschleunigung der Desintegration von zertifizierten bioabbaubaren Biokunststoffen untersucht. Nachdem ein Nachweis der Desintegration verschiedener Biokunststoffe erbracht und aus-reichend hohe Gehalte gelöster Organik nachgewiesen werden, erfolgt im Anschluss die anaerobe Verwertung der erzeugten Flüssigkeiten in einer mesophilen, kontinuierlichen Vergärung. Die Gärtests geben Aufschluss über die Vergärbarkeit, das Biogaspotenzial, die Biogasqualität und die Abbaugrade der desintegrierten Biokunststoffe. Der höchste Abbaugrad (71,3 %) wird bei der Untersuchung der Flüssigkeiten der Ecovio®-Biobeutel erreicht. Der Abbau der Activia®-Becher (39,6 %) verlief weniger effizient und wird durch hohe Gehalte organischer Säuren und Verdünnungseffekte beeinflusst. Die real erzeugten Biogaspotenziale schwanken zwischen 0,1 lN CH4/g CSB und 0,23 lN CH4/g CSB. Die Biogasqualität während der Versuche ist sehr gut. Die Verhältnisse von CH4 zu CO2 liegen überwiegend zwischen 50:50 und 60:40. Der Nachweis der energetischen Nutzbarmachung der desintegrierten Biokunststoffe für den mikrobiellen Umsatz bzw. zur Biogasbildung wird erbracht. Die Implementierung einer Desintegrationsstufe in eine bestehende Vergärungsanlage wird im Hinblick auf die Wirtschaftlichkeit bewertet. Die Implementierung ist technisch realisierbar. Die Kosten der Implementierung übersteigen die Erlöse um ein Vielfaches. Auch bei längeren Betrachtungszeiträumen kann kein Gewinn erwirtschaftet werden.

Protein is essential in one's diet because it is an important component in many organs and tissues throughout the body. Athletes ingest protein in order to stimulate protein synthesis and increase lean muscle mass. In order to assist with obtaining adequate amounts of protein, athletes and bodybuilders purchase supplemental protein in the form of protein powders. Protein metabolism and digestion play key roles in this because if the protein is not metabolized or digested effectively, then those who are wishing to gain fat free mass will not be successful. A high quality protein will be digested, metabolized, and directed towards lean tissue accretion more efficiently than a lower quality protein. In order to be a high quality protein, it must contain the essential amino acids. Fortunately, whey protein is a high quality protein because it contains an abundant supply of the essential amino acids. Whey protein is a high quality protein; hence, many athletes and physically active individuals purchase whey protein supplements. Some individuals do not care about taste and overcome awful protein powder taste, while others value a good tasting whey protein. After extensive research, it appears that scientific taste tests on protein supplements are lacking. The purpose of this study was to test some of the most popular protein supplements (Muscle Milk, BSN, Nesquik Vanilla Milk and Optimum Nutrition) and discover which one tasted the best. In this study, there were 94 males and 68 females. The results showed that there was a difference in initial taste and after taste in protein supplements among a male and female population. The difference among the drinks was statistically significant. The findings showed that both genders thought BSN and Muscle Milk were close to "neither good nor bad" while Nesquick Milk was rated as "good" and Optimum was "bad." The initial taste ratings were BSN (mean=4.05; SD=1.7), Muscle Milk (mean=4.6; SD=1.8), Nesquick Milk (mean=5.4; SD=1.2), and Optimum Nutrition (mean=3.1; SD=1.6). This research study showed that there was a statistically significant difference in taste among protein drinks, but the results do not answer as to why that is. Future research would need to be conducted in order to find the answer as to why there is a difference in initial and after taste.

Digestive proteolysis in termites has not been studied yet. In this diploma thesis, proteolytic enzymes of the digestive tract of two significant pest species Reticulitermes santonensis and Coptotermes formosanus (Rhinotermitidae) were analyzed. Proteases were identified and quantified in gut compartments using a panel of specific substrates and inhibitors. Major proteases were localized in the midgut and were classified as endogenous serine proteases of trypsin type. Minor cysteine proteases were detected in the paunch and were most likely produced by symbionts. The trypsin protease from R. santonensis was chromatographically isolated and its N-terminal sequence was identified. The physiological importance of the digestive trypsin proteases was demonstrated using selective inhibitors tested in vivo with C. formosanus. Based on the analysis of proteases from additional 12 termite species, a general scheme of digestive proteolysis in the order Isoptera was proposed. (In Czech)

No description available.

No description available.

Metals are essential nutrients for plant health, but not all metals are necessary and can sometimes be harmful towards plants depending on factors such as species, elemental composition in the soil and concentration of a metal. Iron (Fe), which is one of the most abundant metals in the earth’s crust is also one the most important nutrients for plant growth, as it is responsible for metabolism. Lead (Pb) has been widely outspoken to be a harmful pollutant to plants and has been shown in studies to have an impact on a plant’s physiology and morphology. The aim of this study is to analyze whether Pb and Fe influence the metal content of Garden cress (Lepidium sativum). A solution of Pb with the following concentrations; 2.4 g/L, 1.2 g/L, 0.48 g/L, 0.24 g/L, 0.12 g/L, 0.048 g/L and 0.024 g/L were used. Another solution of Fe with the following concentrations; 0.56 g/L, 0.28 g/L, 0.11 g/L, 0.056 g/L, 0.028 g/L, 0.011 g/L and 0.0056 g/L were also used. Then a combined solution of both Pb- and Fe solution were mixed with a volume ratio of 1:1 corresponding to the following concentrations of lead and iron, respectively; 0.024/0.0056 g/L, 0.048/0.0112 g/L, 0.12/0.028 g/L, 0.24/0.056 g/L, 0.48/0.112 g/L, 1.2/0.28 g/L were used. A total of 29 different metal contents were analyzed, which include; Aluminum (Al), silver (Ag), Barium (Ba), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Cobalt (Co), Copper (Cu), Fe, gallium (Ga), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), Molybdenum (Mo), sodium (Na), nickel (Ni), Pb, rubidium (Rb), selenium (Se), strontium (Sr), tellurium (Te), thallium (Tl), uranium (U), vanadium (V), zinc (Zn). Before initial analysis, microwave plasma atomic emission spectrometry (MP-AES) was applied with a test sample to evaluate if the acidified digestion method used with nitric acid and hydrogen peroxide was successful enough to be used for the original experiment. It was successful, so the cress samples underwent the same digestion method and were analyzed with inductive coupled plasma mass spectrometry (ICP-MS). The results showed that Pb overall decreased most metal contents, while Fe seemed to generally maintain a constant metal content of most metals. Fe fed cress seemed to grow the healthiest in appearance compared to Pb fed cress which grew the worst. Mixed solution Pb and Fe cress fed grew worse than Fe fed cress, but better than Pb fed cress. The growth quality was the worst with Pb fed and the best for controlled water fed cress. For mixed Pb and Fe solution fed cress the plants seemed to share similar qualities of both Pb- and Fe solution fed cress, with better growth capabilities than Pb fed cress, but worse than Fe fed cress. The high dilution factor during the sample preparation led to the fact that some trace and ultra-trace elements could not be determined, since their contents were below LOD or LOQ. Adapting the sample preparation procedure to these low concentrations would be a further improvement.

Prefabricated baby food is under strict EU legislation by Commission Regulation (EC) 1881/2006 Setting maximum levels for certain contaminants in foodstuffs regarding the maximum allowed content of potentially harmful elements. For potentially toxic trace elements the regulated maximum content is regulated for lead, cadmium, mercury, inorganic tin, inorganic arsenic, cesium, copper and manganese. The Swedish national food agency (Livsmedelsverket) conducts chemical analyses of the regulated elements by full microwave acid digestion followed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis. In this study a simple artificial in vitro digestion method was developed using a commercially available enzyme supplement and optimized to determine the bio-accessible amount of eight potentially harmful metal trace elements that are associated with modern electronics (lithium, vanadium, cobalt, nickel, arsenic, selenium, cadmium and lead) in five prefabricated baby meals from the Swedish market by well-established manufacturers. The results were compared to the total mass content as well as the regulated limits and toxicological literature data. The samples had analyte dry mass contents that were extractable by the developed in vitro method that ranged from 0.0314 μg g-1 to 0.0691 μg g-1 for lithium, 9.42*10-5 μg g-1 to 0.0152 μg g-1 for vanadium, 6.61*10-3 μg g-1 to 30.9*10-3 μg g-1 for cobalt, 0.0599 μg g-1 to 0.194 μg g-1 for nickel, 4.54*10-4 μg g-1 to 0.0431 μg g-1 for arsenic, 8.87*10-4 μg g-1 to 9.85*10-3 μg g-1 for cadmium and 1.24*10-3 μg g-1 to 0.0232 μg g-1 for lead. Selenium was not detected in any of the samples. None of the samples were found to contain toxic levels of any of the quantified elements. Comparisons and paired t-tests of recoveries between the in vitro digestion and control procedures consisting of digestion solutions that exclude either enzymes, pH adjustment or both suggested that lithium, cobalt and cadmium were protein bound and that the digestion enzymes used had a statistically significant effected on the recovery. With further optimization and more extensive comparison to reference data the method could potentially be established as a simple and affordable alternative to more elaborate methods for screening or small scale analysis of the bio-accessible fraction of metal trace elements in food.

Sewage sludge is widely used as an important source for biogas production through digestion. Developing the high performance processes has a significant goal in order to promote energy efficiency and reduce the cost sewage sludge treatment. The problem of sewage sludge disposal is becoming top one which almost cost 50 % of running fee for a municipal wastewater treatment plant. This paper basically introduces three methods to improve the conventional digestion. However, they enhance the conventional digestion from different aspects. For examples, Two-phase anaerobic digestion enables to exhibit the merit of thermophilic anaerobic digestion and avoid the weak points of conventional digestion regarding odor problem. In two-phase anaerobic digestion, the acid and methane producing stages are separated. Extended solids retention time is an approach to separate the hydraulic retention time and solids retention time in an anaerobic digester by using recycle thickening. This method could benefit further de-composing the organics and increase methane formation. Dewaterability is the final step of anaerobic digestion process. Enhancing this part of process is an efficient way to increase the solid content of sludge that would reduce the transportation costs. In a nutshell, no matter on saving cost or energy perspectives, these three methods all promote biogas production efficiency up to a better performance, but various requirement of energy and cost are demanded. The paper displays and compares the advantages and disadvantages among three methods. There is no certain answer to which method is the best one; however, they can be chose to enhance digestion in different condition.

Sewage sludge is treated with the biological process of anaerobic digestion in which organic material of a substrate is degraded by microorganisms in the absence of oxygen. The result of this degradation is biogas, a mixture mainly of methane and carbon dioxide. Biochemical Methane Potential tests are used to provide a measure of the anaerobic degradability of a given substrate. This study aims to determine the methane potential in Sjöstadsverket’s sludge this will moreover determine the viability of recycling the digested sludge back into the anaerobic system for further digestion. Batch digestion tests were performed in both Sjöstadsverket’s (S1) and Henriksdal’s (H2) sludge, for a reliable comparison. An inoculum to substrate ratio of 2:1 based on VS content was used and BMP tests presented results that S1 and H2 in the 20 days of incubation produced 0.29 NLCH4/gVS and 0.33 NLCH4/gVS respectively. A second experiment considering the same amount of substrate (200ml) and inoculum (200ml) for each sample, showed that Control S1 had a higher methane potential than Control H2, 0.31 NL/gVS and 0.29 NL/gVS respectively. All the samples containing Sjöstadsverket’s inoculum presented a higher volume of total accumulated gas (measured in Normal Liters), however methane potentials are low. Results demonstrated that methane production in samples S1 and Control S1 was originating from the grams of VS in the inoculum itself after depletion of all the soluble organic material in the substrate. This suggested that Sjöstadsverket’s sludge can endure a higher organic load rate and that the digested sludge still has potential to produce biogas, hence the recycling of this can enhance the biogas production in the digestion system.