Detection Of Discoloration Research Articles

Detection of discoloration in diesel fuel based on gas chromatographic fingerprints.

In the countries of the European Community, diesel fuel samples are spiked with Solvent Yellow 124 and either Solvent Red 19 or Solvent Red 164. Their presence at a given concentration indicates the specific tax rate and determines the usage of fuel. The removal of these so-called excise duty components, which is known as fuel “laundering”, is an illegal action that causes a substantial loss in a government’s budget. The aim of our study was to prove that genuine diesel fuel samples and their counterfeit variants (obtained from a simulated sorption process) can be differentiated by using their gas chromatographic fingerprints that are registered with a flame ionization detector. To achieve this aim, a discriminant partial least squares analysis, PLS-DA, for the genuine and counterfeit oil fingerprints after a baseline correction and the alignment of peaks was constructed and validated. Uninformative variables elimination (UVE), variable importance in projection (VIP), and selectivity ratio (SR), which were coupled with a bootstrap procedure, were adapted in PLS-DA in order to limit the possibility of model overfitting. Several major chemical components within the regions that are relevant to the discriminant problem were suggested as being the most influential. We also found that the bootstrap variants of UVE-PLS-DA and SR-PLS-DA have excellent predictive abilities for a limited number of gas chromatographic features, 14 and 16, respectively. This conclusion was also supported by the unitary values that were obtained for the area under the receiver operating curve (AUC) independently for the model and test sets.

Detection of discoloration in thermally processed blue crab meat

This study objectively and quantifiably examined the effect of a series of factors on blue crab meat discoloration. Factors explored include heating process, animal harvest location, and position of meat within a container. A Spectrogard colorimeter was used to collect visual reflectance spectra between 380 and 720 nm. Meat degree of coloration was characterised objectively and rapidly by using lightness (L), red–green (a) and yellow–blue (b) colour values. Results showed that meat became darker with increasing heating process; crab harvest location had significant effect on the lightness of the flesh; and meat that is located in the bottom of a can was darker than that in the top. This study will serve as a baseline for the development of a coloration quality control system. © 1999 Society of Chemical Industry

Detection of discoloration in thermally processed blue crab meat

Detection of discoloration in thermally processed blue crab meat

Field and laboratory guide to tree pathology

Concepts and Techniques for Understanding, Identifying, And Controlling Tree Diseases: Tree Biology. Sterile Technique. Diagnostic Techniques. Preservation of Diseased Specimens and Pathogens. Models. Symptomatology. General Control Strategies. Diseases Caused By Infectious Agents: Fungi. Foliage Diseases. Vascular Wilt Diseases. Canker Diseases. Rust Diseases. Root Diseases. Discoloration and Decay in Living Trees. Bacterial Diseases. Vascular Bacterial Diseases. Virus Diseases. Nematode Diseases, Diseases Caused By Parasitic Seed Plants. Diseases Caused By Noninfectious Agents: Temperature Extremes. Moisture Extremes. Nutrient Abnormalities. People Pressure Diseases. Field and Laboratory Exercises: Symptoms and Signs. Collection and Identification of Powdery Mildews. Disease Sample Collection. Isolations of Vascular Wilt Pathogens. Detection of Starch Reserves in Trees. Koch's Postulates. Extraction of Nematodes from Soil and Roots. Observations of Mycorrhizae. Development of Crown Gall. Appraisal of Shade Trees. Detection of Hazard Trees. Effects of Salt on Tree Seedlings. Detection of Discoloration and Decay in Wood. Glossary. Index. Figure Captions.