TY - JOUR A1 - Tillich, Ulrich M. A1 - Wolter, Nick A1 - Schulze, Katja A1 - Kramer, Dan A1 - Brödel, Oliver A1 - Frohme, Marcus T1 - High-throughput cultivation and screening platform for unicellular phototrophs JF - BMC Microbiology N2 - In this work we describe and test high-throughput methods with the model organism Synechocystis sp. PCC6803. The required technical automation for these processes was achieved with a Tecan Freedom Evo 200 pipetting robot. The cultivation was performed in 2.2 ml deepwell microtiter plates within a cultivation chamber outfitted with programmable shaking conditions, variable illumination, variable temperature, and an adjustable CO2 atmosphere. Each microtiter-well within the chamber functions as a separate cultivation vessel with reproducible conditions. The automated measurement of various parameters such as growth, full absorption spectrum, chlorophyll concentration, MALDI-TOF-MS, as well as a novel vitality measurement protocol, have already been established and can be monitored during cultivation. Measurement of growth parameters can be used as inputs for the system to allow for periodic automatic dilutions and therefore a semi-continuous cultivation of hundreds of cultures in parallel. The system also allows the automatic generation of mid and long term backups of cultures to repeat experiments or to retrieve strains of interest. KW - cyanobacteria KW - synechocystis KW - HTS KW - high throughput KW - automated cultivation Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-6007 SN - 1471-2180 VL - 14 IS - 239 ER - TY - JOUR A1 - Kipkorir, R. A1 - Muhoho, S. A1 - Muliro, P. A1 - Mugendi, Beatrice A1 - Frohme, Marcus A1 - Brödel, Oliver T1 - Effects of Coffee Processing Technologies on Aroma Profiles and Sensory Quality of Ruiru 11 and SL 28 Kenyan Coffee Varieties JF - Asian Journal of Agriculture and Food Sciences N2 - The study aimed at comparing the effects of three coffee processing methods on aroma profiles and sensory quality of Ruiru 11 and SL 28 coffee varieties. The processing methods varied on stages of processing and method of mucilage removal. The green coffee beans obtained from the three processing methods were graded and roasted, ground and analyzed for the aroma profiles and sensory quality. Headspace Solid phase Microextraction fibre (SPME) technique were used for the extraction of aroma compounds from coffee samples and characterization of the compounds with use of gas chromatography mass spectrometry (GC-MS). Sensory quality were analyzed by an expert panelist. Various volatile aroma compounds were identified in roasted coffee and classified into their chemical classes involving furans, ketones, pyrazines ketones pyridines, pyrroles and acids. The intensity of aroma compounds were compared in terms of their peak areas and variations were noted between the processing methods with the ecopulper showing higher levels of pyrazines such as 2-methylpyrazine, 2-ethyl-6-methylpyrazine, and wet pulper showing higher levels of furans such as furfuryl formate and furfuryl alcohol, acetate. The hand pulper was high in the level of acids and esters such as acetic acid and propanoic acid, ethyl ester. Similar aroma compounds were identified in headspace of Ruiru 11 and SL 28 and there were variations in the intensities of aroma groups such as pyrroles and pyridines. It was concluded that the eco-pulper and hand pulper methods gives better aroma quality than the wet pulper while SL 28 variety gives higher sensory quality than Ruiru 11. KW - coffee KW - processing KW - aroma KW - sensory quality Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-6482 UR - https://ajouronline.com/index.php/AJAFS/article/view/2551 SN - 2321-1571 VL - 3 IS - 2 SP - 178 EP - 188 ER - TY - JOUR A1 - Kinuthia, Chuaga A1 - Frohme, Marcus A1 - Brödel, Oliver A1 - Mugendi, Beatrice T1 - LCMS Analysis of Biochemical Composition in Different Kenyan Coffee Classifications JF - Food Science and Quality Management N2 - Kenyan coffee is classified by defects after grading by the ‘Devonshire method.’ The method involves classification of the coffee beans into different classes based on the raw and roasted coffees and cup quality, with class one being the best and ten the poorest. In this study, the relationship between classification of the coffee and the content of sucrose, trigonelline, caffeine and chlorogenic acids was determined by simultaneous LC-MS analysis. By using the sensory variables the class 3 coffee portrayed the best quality, followed by class 4 and 5 which were placed further distinctively from the other classes (6, 7, 8 and 9). The class 3 coffee had a high percent of non-defective beans with 94.31% and class 9 had a high defect count at 79.53% hence the defective beans increased with decrease in coffee class. The caffeine concentration in green coffee for class 3 coffee was significantly different from the rest of the coffees at 1.23 ± 0.00g/100g. A higher content of trigonelline levels was observed as the quality of the green coffee decreased in classes 6, 7 and 8. The highest level of sucrose in green coffee beans was observed in class 3 coffee and the lowest in the class 9. Lower content of chlorogenic acids were observed among the high quality coffees i.e. class 3, 4 and 5 with class 3 having the lowest while a higher content was observed among the lower quality coffees i.e. classes 6, 7 and 9 with class 6 having a higher content was it significantly different in class 6 compared to 7 and 9?. Quantities of different chemical components among the classes are clear indicators that the classification method used on the Kenyan coffees brings out the differences in coffee quality based on the analysis of the green and the roasted coffees. KW - biochemical composition KW - coffee classification KW - LCMS Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-10185 UR - http://iiste.org/Journals/index.php/FSQM/article/view/39645 SN - 2225-0557 VL - 69 SP - 44 EP - 52 ER - TY - JOUR A1 - Praia, Ana Beatriz A1 - Herkenhoff, Marcos Edgar A1 - Brödel, Oliver A1 - Frohme, Marcus A1 - Saad, Susana Marta Isay T1 - Sour Beer with Lacticaseibacillus paracasei subsp. paracasei F19: Feasibility and Influence of Supplementation with Spondias mombin L. Juice and/or By-Product JF - Foods N2 - This study aimed to evaluate the probiotic strain Lacticaseibacillus (L.) paracasei subsp. paracasei F19 (F19) with the yeast Saccharomyces cerevisiae US-05 (US-05), using Spondias mombin L. (‘taperebá’ or ‘cajá’) juice and by-product, in four sour-type beer formulations: control, with bagasse, juice, and juice and bagasse. The viability of F19 was evaluated by pour-plating and PMA-qPCR. Fermentability, in addition to physicochemical and sensory parameters, and aroma and flavor, were evaluated during brewery by using Headspace Solid-Phase Microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS). F19 was successful in fermenting bagasse in a MRS medium (9.28 log CFU/mL in 24 h) but had a low viability in hopped wort, growing better in formulations without bagasse or juice. No difference between formulations was observed regarding sensory acceptability, and the HS-SPME/GC-MS revealed different flavors and aroma compounds. In conclusion, the production of a potential probiotic sour beer with F19 and US-05 is feasible regarding probiotic viability. However, S. mombin, as juice or bagasse, threatened probiotic survival. Different flavors and aroma compounds were detected, whereas no difference between formulations was found regarding sensory acceptability. The moderate alcohol content achieved is important for bacterial survival and for the development of a probiotic beer with health claims. KW - sour beer KW - probiotics KW - co-fermentation KW - fruit by-product Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16852 SN - 2304-8158 VL - 11 IS - 24 PB - MDPI ER - TY - GEN A1 - Gering, Vanessa A1 - Kober, Liane A1 - Brödel, Oliver A1 - Koskei, Richard A1 - Mugendi, Beatrice A1 - Frohme, Marcus T1 - LC-MS/MS als Methode zur Detektion und Quantifizierung der Inhaltsstoffe in Kaffee T2 - Wissenschaftliche Beiträge 2017 N2 - Kaffee ist das wohl populärste Heißgetränk weltweit. Zwei botanische Arten sind für den Weltmarkt von Bedeutung und unterscheiden sich bezüglich ihres Anbaugebietes und der Inhaltsstoffe. Kaffee enthält über 850 bisher identifizierte Aromastoffe, welche den Geschmack bilden. Außerdem haben die Prozessierung der geernteten Kirsche bis zur Bohne, das Röstprofil und das Aufbrühen einen großen Einfluss darauf. In dieser Arbeit wurde die Auswirkung der Prozessierungsmethode auf ausgewählte Inhaltsstoffe mit Hilfe der Flüsssig-Chromatographie-Tandem-Massenspektroskopie (LC-MS/MS) untersucht. Dafür wurden drei Prozessierungsmethoden, die unterschiedlich viel Wasser für das Ablösen des Fruchtfleisches von den Kaffeekirschen benötigen, und zwei Kultursorten miteinander verglichen. Die Ergebnisse zeigten einen geringfügig höheren Gehalt der zwei wichtigsten Inhaltsstoffe Koffein und Chlorogensäure in den Bohnen, bei deren Prozessierung im Eco-Pulper-Verfahren weniger Wasser eingesetzt wurde. Bis auf einen verringerten Gehalt an Saccharose wurde für weitere wichtige Inhaltsstoffe (Acrylamid, Niacin, Zitronensäure und Vanillin) kein signifikanter Unterschied bei höherem Wassereinsatz gefunden. Insofern man die untersuchten Inhaltsstoffe als Qualitätsmarker betrachtet, ist im Vergleich zu den anderen Prozessierungsmethoden das Eco-Pulper-Verfahren die beste Wahl, insbesondere da es als wassersparende Methode einen entscheidenden Beitrag zur Nachhaltigkeit des Kaffeeanbaus leistet. N2 - Coffee is the most popular soft drink in the world. Two botanical species of coffee are important for the world market and differ not only in their area of cultivation but also their components. Coffee contains more than 850 aromatic compounds which constitute its taste and flavour. Also, the method selected for the processing from the harvested cherry to the bean, the roasting profile, and the method of brewing are relevant. In this work, liquid chromatography tandem-mass-spectroscopy (LC-MS/MS) is used to investigate how the processing method influences selected aromatic compounds. Thus, three different processing methods differing in the amount of water needed for separating the coffee beans from the cherries, and two cultivars were compared. The results showed slightly higher concentrations of the caffeine and chlorogenic acid components in coffee processed with less water (the eco-pulper method). Apart from a reduced sucrose concentration, we found no significant difference in other important compounds (acrylamide, niacin, citric acid and vanillin) when plenty of water was used. Taking the investigated compounds as quality markers, the eco-pulper method is the best choice among the processing methods, especially since it conserves water, which could therefore significantly contribute to a sustainable cultivation of coffee. Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9362 SN - 0949-8214 VL - 21 SP - 7 EP - 12 ER - TY - JOUR A1 - Herkenhoff, Marcos Edgar A1 - Bovolenta, Luiz A. A1 - Brödel, Oliver A1 - dos Santos, Lucilene D. A1 - de Oliveira, Arthur C. A1 - Chuffa, Luiz G.A. A1 - Ribeiro, Amanda O. A1 - Lupi, Luiz A. A1 - Dias, Marco A.D. A1 - Hilsdorf, Alexandre W.S. A1 - Frohme, Marcus A1 - Pinhal, Danillo T1 - Variant expression signatures of microRNAs and protein related to growth in a crossbreed between two strains of Nile tilapia (Oreochromis niloticus) JF - Genomics N2 - Nile tilapia (Oreochromis niloticus) is a species of worldwide importance for aquaculture. A crossbred lineage was developed through introgressive backcross breeding techniques and combines the high growth performance of the Chitralada (CHIT) lwith attractive reddish color of the Red Stirling (REDS) strains. Since the crossbreed has an unknown genetically improved background, the objective of this work was to characterize expression signatures that portray the advantageous phenotype of the crossbreeds. We characterized the microRNA transcriptome by high throughput sequencing (RNA-seq) and the proteome through mass spectrometry (ESI-Q-TOF-MS) and applied bioinformatics for the comparative analysis of such molecular data on the three strains. Crossbreed expressed a distinct set of miRNAs and proteins compared to the parents. They comprised several microRNAs regulate traits of economic interest. Proteomic profiles revealed differences between parental and crossbreed in expression of proteins associated with glycolisis. Distinctive miRNA and protein signatures contribute to the phenotype of crossbreed. KW - Nile tilapia KW - growth KW - RNA-seq KW - miRNA KW - ESI-Q-TOF KW - proteome Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15571 SN - 0888-7543 VL - 113 IS - 6 SP - 4303 EP - 4312 PB - Elsevier ER - TY - JOUR A1 - Bauer, Joachim A1 - Fursenko, Oksana A1 - Heinrich, Friedhelm A1 - Gutke, Marko A1 - Kornejew, Eckhart A1 - Brödel, Oliver A1 - Dietzel, Birgit A1 - Kaltenbach, Alexander A1 - Burkhardt, Martin A1 - Edling, Matthias A1 - Steglich, Patrick A1 - Herzog, Michael A1 - Schrader, Sigurd T1 - Determination of optical constants and scattering properties of transparent polymers for use in optoelectronics JF - Optical Materials Express N2 - Knowledge of optical constants, i.e. refractive index n and extinction coefficient k, and light scattering properties of optical polymers are required to optimize micro-optics for light-emitting diodes in terms of efficiency, color properties and light distribution. We present here a model-based diagnostic approach to determine the optical properties of polymers, which should be particularly useful in the development of plastics for optical applications. Optical constants and scattering coefficients were obtained from transmission and reflection measurements in a wavelength range from UV to NIR taking into account scattering effects due to rough surfaces and volume inhomogeneity. Based on the models for the dielectric function, the molecular optical transition energies Eg, critical point energies, Urbach energies and exciton transition energies were determined. Rayleigh and Mie scattering model and van de Hulst's anomalous diffraction theory were applied to characterize scattering due to volume inhomogeneities. Scalar diffraction theory was applied to account for surface roughness scattering. Atomic force microscopy with nanomechanical characterization was used to characterize domains in size and shape and to assign optical scattering to a suitable morphological model. The combined optical and mechanical characterization help to improve the qualification of new polymer materials for optical applications. KW - diffraction theory KW - light property KW - optical constant KW - optical material KW - optical property KW - scattering theory Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15666 VL - 12 IS - 1 SP - 204 EP - 224 PB - Optica Publishing Group ER -