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Paste Samples (paste + sample)

Distribution by Scientific Domains
Chemistry75%

Selected Abstracts

Molecular detection of marine bacterial populations on beaches contaminated by the Nakhodka tanker oil-spill accident

ENVIRONMENTAL MICROBIOLOGY, Issue 4 2001
Yuki Kasai
In January 1997, the tanker Nakhodka sank in the Japan Sea, and more than 5000 tons of heavy oil leaked. The released oil contaminated more than 500 km of the coastline, and some still remained even by June 1999. To investigate the long-term influence of the Nakhodka oil spill on marine bacterial populations, sea water and residual oil were sampled from the oil-contaminated zones 10, 18, 22 and 29 months after the accident, and the bacterial populations in these samples were analysed by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments. The dominant DGGE bands were sequenced, and the sequences were compared with those in DNA sequence libraries. Most of the bacteria in the sea water samples were classified as the Cytophaga,Flavobacterium,Bacteroides phylum, ,- Proteobacteria or cyanobacteria. The bacteria detected in the oil paste samples were different from those detected in the sea water samples; they were types related to hydrocarbon degraders, exemplified by strains closely related to Sphingomonas subarctica and Alcanivorax borkumensis. The sizes of the major bacterial populations in the oil paste samples ranged from 3.4 × 105 to 1.6 × 106 bacteria per gram of oil paste, these low numbers explaining the slow rate of natural attenuation. [source]

Phase composition depth profiles using spatially resolved energy dispersive X-ray diffraction

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2004
Andrew C. Jupe
Spatially resolved energy dispersive X-ray diffraction, using high-energy synchrotron radiation (,35,80,keV), was used nondestructively to obtain phase composition profiles along the radii of cylindrical cement paste samples to characterize the progress of the chemical changes associated with sulfate attack on the cement. Phase distributions were acquired to depths of ,4,mm below the specimen surface with sufficient spatial resolution to discern features less than 200,µm thick. The experimental and data analysis methods employed to obtain quantitative composition profiles are described. The spatial resolution that could be achieved is illustrated using data obtained from copper cylinders with a thin zinc coating. The measurements demonstrate that this approach is useful for nondestructively visualizing the sometimes complex transformations that take place during sulfate attack on cement-based materials. These transformations can be spatially related to microstructure as seen by computed microtomography. [source]

QUALITY AND CONSUMER ACCEPTANCE OF AKARA (FRIED COWPEA PASTE) PROCESSED FROM WET- AND DRY-MILLED COWPEA (VIGNA UNGUICULATA) MEAL WITH SPECIFIED PARTICLE SIZE DISTRIBUTION

JOURNAL OF FOOD QUALITY, Issue 3 2007
MELISSA A. VANCHINA
ABSTRACT Direct quality indicators of cowpea paste and akara produced from traditionally wet-milled peas, and hammer-milled (dry-milled) and freeze-dried (wet-milled) meals were examined in this study. Both meal samples studied were formulated to consist of 65% medium-sized particles and 35% large particles by weight. Particle volume mean diameters (µm) of the three paste samples were not significantly different from one another at the various stages during akara production. Scanning electron micrographs of akara crumb were converted to threshold images and analyzed. There was no significant difference in the amount of air found in the akara samples. Akara produced from both meals was found acceptable by sensory panelists with no significant difference in any of the attributes or overall liking among the three samples. [source]

Evaluation of heat and oxidative damage during storage of processed tomato products.

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2002

Abstract The evolution of heat damage during storage of tomato pulp, puree and paste was studied by accelerated aging tests. Heat damage indices,5-hydroxymethyl-2-furfural (HMF), furosine and colour changes (,E),were evaluated for tomato products stored at 30, 40 and 50,°C for up to 90 days. Furosine and ,E values increased following pseudo-zero-order kinetics, and the higher the solid content of the products, the higher were the rate constant values. HMF formation followed pseudo-first-order kinetics in tomato pulp and pseudo-zero-order kinetics in puree and paste samples. Data show that heat damage reactions in tomato products proceed even at room temperature, and the kinetic model provided can be used to predict changes occurring during shelf-life. © 2002 Society of Chemical Industry [source]