Kinetic modeling of U.V. disinfection of water

The response of pure cultures of Escherichia coli, Candida parapsilosis, and bacterial virus f2 to ultraviolet light radiation was studied in a batch reactor and in a completely mixed, flow-through annular reactor. Two kinetic models were tested as to their ability to scale between batch results and flow-through reactor results. Using the respective best-fit kinetic parameters for each model from batch data, the response of the organisms in the flow-through reactor could be predicted by using either multi-target kinetics or series-event kinetics. The series-event model was judged to be superior to multi-target kinetics because it better represents the known mechanism of u.v. inactivation than does multi-target kinetics. Since two different models can be used to describe the data, the simple agreement between experimental data and model predictions does not necessarily prove that either model is mechanistically correct.     

Zur Spezifität des Kakaoaromas

Specificity of Cocoa Aroma Aroma precursors in crude cocoa from Ghana were separated into substance classes and their significance in aroma formation was examined. Coaction of a peptide, which was isolated and characterized for the first time, is especially necessary for the specific reaction which occurs via a side path of Maillard-reaction. Furthermore, aroma formation in other varieties of cocoa was studied on the basis of precursors. From chemical viewpoint the 310 aroma components known so far were classified and compared with other food aromas in order to obtain information on the specific components.     

Bildung eines Pyridon-Derivates aus Maltose und Lactose XII. Untersuchungen zur Maillard-Reaktion

Zusammenfassung Maltose und Lactose reagieren mit Methylammoniumacetat in heißer, wäßriger Lösung rasch unter Bräunung. Aus dem Gemisch der flüchtigen Produkte ist 1,2-Dimethyl-3-hydroxy-pyridon-(4) ( ) in verhältnismäßig großer Menge isolierbar. Auch Maltol ( ) und Isomaltol ( ) lassen sich mit Methylammoniumacetat zu dem Pyridon 5 umsetzen. Aus Isomaltol und Glycin erhält man 1-Carboxymethyl-3-hydroxy-2-methyl-pyridon-(4) (9).

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Formation of pyridone derivates from maltose and lactoseXII. Investigations on the Maillard-Reaction

Summary Maltose and lactose react with methylammoniumacetate in a hot aqueous solution giving a dark brown mixture of products. 1,2-dimethyl-3-hydroxy-4-pyridone ( ) can be isolated from the volatile compounds. Maltol and Isomaltol can be converted into the pyridone with methylammoniumacetate. 1-Carboxymethyl-3-hydroxy-2-methyl-4-pyridone is obtained from isomaltol and glycine.

     

Nachweis von 2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-on in Lebensmitteln

2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-on (1) wurde in verschiedenen erhitzten Lebensmitteln nachgewiesen. Es bildet sich beim Kochen von Karotten, Zwiebeln, Tomaten und Kohl sowie beim Erhitzen von Fleisch.1 entsteht auch bei der Karamellisierung von Mono- und Disacchariden; es findet sich daher in Karamelbonbons, gebrannten Mandeln und Brotkruste. Die Bildung wird durch primäre Amine, Aminosäuren und Eiweiß katalysiert.     

Influence of digit grouping on memory for telephone numbers.

4distinct patterns of 60 7-digit numbers were compared for accuracy of dialing by 96 college students. The patterns consisted of the following number of digits separated by hyphens: 3-4, 1-3-3, 2-2-3, and 1-2-2-2. A memory drum was used for presentation of the digits and a telephone for dialing. The tapes for the memory drums contained 4 lists of the same digits, the lists differing in the pattern for each set of digits and in the sequence of the patterns. Data analyzed in a 4 X 4 X 4 design for repeated measurement showed the 3-4 pattern, the pattern in current usage, to be superior to the others (p