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

Zusammenfassung 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.

---

Proof of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-on in foods

Summary 2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-on is proved in various cooked food products. It is formed when carrots, onions, tomatoes, cabbage and meat are heated. It is also present in caramelized mono- and disaccharides, in caramel sweets and bread crusts. The formation of this compound is due to the catalytic effect of primary amines, amino acids and protein.

     

Market power in California electricity markets

As the electricity industry in California undergoes a process of fundamental restructuring, important new products and markets will be created while others will lose significance. In this paper, we undertake an initial survey of the products and markets that will be prominent in the emerging new electricity industry. We describe approaches to analyzing the prospects for, and the impacts of, market power abuse in these various product markets. The key product markets that are discussed include those for spot electrical energy, for pool-based and physical power contracts, and for reliability services such as load balancing and spinning reserve. Structural measures of market power, such as the Hirschman-Herfindahl Index (HHI), have certain general shortcomings that are exacerbated when applied to restructured electricity markets. Fortunately, the direct estimation of competitive equilibria, such as a Cournot oligopoly equilibrium, appears to be more feasible for this industry than is generally the case.     

Search for a protein kinase specific for treponin T

A specific to troponin T (as compared to f1 histone) proteinkinase is isolated using affinity chromatography on Sepharose 4B with covalently bound dephosphorylated troponin T. Homogeneous proteinkinase has a molecular weight of 175.000 and phosphorylates troponin T at a rate exceeding that of histone phosphorylation, while crude proteinkinase preparation has troponin T phosphorylation rate 15--20 times as low as that of histone phosphorylation. The enzyme isolated is capable of phosphorylating troponin T, but not troponin I, in the whole troponin complex.