Lipid oxidation in potato chips

Qualitative and quantitative analyses of volatile compounds in fresh and aged potato chips and unused fresh and aged frying oils showed that oxidation of oils was mainly responsible for volatile compound changes in potato chips during storage. The lipid oxidation of potato chips was determined by measuring the peroxide value of potato chips and the amount of volatile compounds and oxygen content in the headspace of potato chip bottles by gas chromatography. The correlation coefficients between volatile compounds and oxygen content, volatile compounds and peroxide value, and peroxide values and oxygen content were -0.93, 0.95 and -0.93, respectively. These high correlation coefficients indicated that volatile compound changes in potato chips during storage were mainly due to the oxidation of oil. The lipid oxidation of potato chips during storage can be studied by measuring oxygen content and the amount of volatile flavor compounds in the headspace. The potato chips produced in oil containing an antioxidant tertiarybutyl hydroquinone (TBHQ) had better oxidation stability than the chips fried in oil without TBHQ.     

Mapping of the trifunctional fatty acid synthetase gene FAS2 on chromosome XVI of Saccharomyces cerevisiae

The trifunctional FAS2 gene encoding subunit alpha of the Saccharomyces cerevisiae fatty acid synthetase complex was mapped on the left arm of chromosome XVI 24 centimorgans proximal to GAL4 and 39 centimorgans distal to PEP4 relative to the centromere. Mapping was achieved by three independent methods: meiotic co-segregation of FAS2 and ARO7 in recombination-deficient spo11-mutants: tetrad analysis of crosses between FAS2, GAL4 and PEP4; and Southern hybridization of purified FAS2 DNA with individual yeast chromosomes separated by pulsed-field gel electrophoresis.     

Mitteilungen der Schweizer Informatik Gesellschaft 3/2006

Ohne Zusammenfassung     

Realization of dot DFB lasers

Dot lasers with first-, second- and third-order gain coupled distributed feedback (DFB) gratings have been realized by low damage dry etching in combination with wet chemical etching and epitaxial over-growth. This technique allows above room temperature (RT) operation of dot DFB lasers with dot diameters down to 85 nm. The laser spectra show the expected emission of gain coupled DFB lasers. Threshold current densities between 1.1 kA/cm/sup 2/ and 2.6 kA/cm/sup 2/ could be obtained depending on size of the active region. An improvement in T/sub 0/ could be demonstrated comparing 0-D/1-D/2-D lasers on the same wafer. Based on the dot grating geometry improvement of the side mode suppression ratio (SMSR) was observed for broad-area dot DFB lasers.     

Drosophila coracle, a member of the protein 4.1 superfamily, has essential structural functions in the septate junctions and developmental functions in embryonic and adult epithelial cells

Although extensively studied biochemically, members of the Protein 4. 1 superfamily have not been as well characterized genetically. Studies of coracle, a Drosophila Protein 4.1 homologue, provide an opportunity to examine the genetic functions of this gene family. coracle was originally identified as a dominant suppressor of EgfrElp, a hypermorphic form of the Drosophila Epidermal growth factor receptor gene. In this article, we present a phenotypic analysis of coracle, one of the first for a member of the Protein 4. 1 superfamily. Screens for new coracle alleles confirm the null coracle phenotype of embryonic lethality and failure in dorsal closure, and they identify additional defects in the embryonic epidermis and salivary glands. Hypomorphic coracle alleles reveal functions in many imaginal tissues. Analysis of coracle mutant cells indicates that Coracle is a necessary structural component of the septate junction required for the maintenance of the transepithelial barrier but is not necessary for apical-basal polarity, epithelial integrity, or cytoskeletal integrity. In addition, coracle phenotypes suggest a specific role in cell signaling events. Finally, complementation analysis provides information regarding the functional organization of Coracle and possibly other Protein 4.1 superfamily members. These studies provide insights into a range of in vivo functions for coracle in developing embryos and adults.     

Low molecular weight carbohydrates from leguminous seeds; a new disaccharide: Galactopinitol

Twelve mature leguminous seed crops were extracted with 70% ethanol, and their low molecular weight carbohydrates estimated by gas chromatography. Pinitol (3-O-methyl-D-chiro-inositol) and three isomers of a new disaccharide, α-D-galactopyranosyl-pinitol, for which the name galactopinitol is proposed, were isolated from soya beans (Glycine max). Pinitol and galactopinitol were also identified in chick peas (Cicer arietinum L.), lentils (Lens esculenta) and beans (Phaseolus vulgaris L.). Their amounts ranged from 0.2 to 0.9% and 0.03 to 0.8% of dry weight respectively. The possible role of galactopinitol in biosynthesis of the sugars of the raffinose family and in flatulence is discussed.     

High-Temperature Oxidation and Smelt Deposit Corrosion of Ni-Cr-Ti Arc-Sprayed Coatings

High Cr content Ni-Cr-Ti arc-sprayed coatings have been extensively applied to mitigate corrosion in black liquor recovery boilers in the pulp and paper industry. In a previous article, the effects of key spray parameters on the coating’s microstructure and its composition were investigated. Three coating microstructures were selected from that previous study to produce a dense, oxidized coating (coating A), a porous, low oxide content coating (coating B), and an optimized coating (coating C) for corrosion testing. Isothermal oxidation trials were performed in air at 550 and 900 °C for 30 days. Additional trials were performed under industrial smelt deposits at 400 and 800 °C for 30 days. The effect of the variation in coating microstructure on the oxidation and smelt’s corrosion response was investigated through the characterization of the surface corrosion products, and the internal coating microstructural developments with time at high temperature. The effect of long-term, high-temperature exposure on the interaction between the coating and substrate was characterized, and the mechanism of interdiffusion was discussed.