Chemical and Instrumental Analyses of Warmed-Over Flavor in Beef

Raw, freshly cooked, stored and recooked beef muscle samples were assessed by chemical, instrumental and sensory methods of analyses for flavor quality, with particular emphasis on warmed-over flavor (WOF). The character notes used by a trained sensory panel to describe WOF were cardboardy, rancid, stale, and metallic. Samples analyzed by direct gas chromatography utilizing either packed or fused silica capillary columns showed that compounds usually associated with lipid oxidation reactions could be used as marker compounds to follow the development of WOF. Of the many compounds that appeared to be markers, hexanal and 2,3-octanedione as well as total volatiles showed a highly significant degree of correlation when compared to sensory scores and 2-thiobar bituric acid (TBA) numbers. Many of the volatile compounds that were identified in WOF meat samples were also found in the distillates prepared for the TBA reaction.     

Characterization by Nuclear and Spectrophotometric Analysis of Near-Surface Modifications of Glass Implanted with Heavy Ions

A soda-lime-silica glass was irradiated by different heavy ion (N, Ne, Ar, and Kr) with energies chosen in order to obtain the same penetration depth. The near-surface sodium depletion layer, characterized by nuclear analysis and infrared reflectance spectrophotometry (IRRS), is deeper than the implanted-ion range and grows with increasing incident-ion mass at the same dose and current density. By using reflectance spectrophotometry in the solar range, the formation of a near-surface perturbed layer having a modified refractive index as compared to the bulk and a thickness comparable to the sodium depletion layer was confirmed.     

SOLUBLE PEROXIDASE ACTIVITY IN PURPLE, GREEN AND WHITE EGGPLANTS

Soluble peroxidase activity extracted from purple, green and white eggplants (Solanum melongena L.) was measured spectrophotometrically. Activity was significantly higher in the white variety than in the other two. The isozyme patterns were compared by polyacrylamide gel electrophoresis. The purple and green had 3 major isozyme bands between 0.8 and 0.9 Rf while the white contained 2. Only the white and purple cultivars contained bands between 0.06 and 0.3 and 0.6 and 0.7 Rf.     

The anthocyanins of sunflower

The extraction process of red pigments from the husks of a cultivar of sunflower has been studied. It has been shown that a fraction containing circa 80% of the starting pigments could be obtained by grinding. Best extractions were obtained with distilled water-organic solvent mixtures of intermediate polarity values. The extraction yields are strongly influenced by the pH and the solvent/powder ratio and reach the maximum after about 2 hr.
The experimental data showed that the greater part of the pigments, readily precipitable by acidification to pH 2.0, are bonded to a macromolecule, probably of protein nature, as confirmed by electrophoresis.     

Vibrio cholerae in Marine Foods and Environmental Waters: A Literature Review

Seafoods have been implicated in a number of cholera outbreaks in the United States and abroad. The incidence of Vibrio cholerue in the environment may be attributed to its extended survival in seawater or to short- or long-term carriers. Strains of V. cholerue which do not agglutinate in 0 group 1 antiserum (NAG) have been associated with a number of gastroenteritis, septicemia, and meningoencephalitis cases in recent years, and genetic studies illustrate a close relationship between the deoxyribonucleic acid (DNA) of NAG and V. cholerae. The ability of NAGS to elicit responses in toxigenicity testing systems similar to those caused by V. cholerae has also been demonstrated. The incidence of NAGS and V. cholerue in U.S. coastal waters and seafoods, their survival, and the conditions that promote genetic changes and increase NAG virulence must be fully evaluated to determine the public health significance of these organisms. These studies are needed to reevaluate the effectiveness of the National Shellfish Sanitation Program (NSSP) growing area standards and criteria so that consumers may be protected against shellfish-associated vibrio diseases.     

Fibroblast growth and polymorphonuclear granulocyte activation in the presence of a new biologically active sol–gel glass

The search for chemical devices to be used in clinical orthopaedics must find substances that are biocompatible and do not elicit inflammatory responses in vivo. To this end, a new form of glass has been prepared, composed of 8.1% CaO, 2.9% P2O5, 6.7% N2O5 and 82.3% SiO2, using sol–gel procedures. In order to evaluate the in vitro biocompatibility of this glass, the proliferation of cultured murine fibroblasts and the activation of human polymorphonuclear leukocytes has been studied. The performance of the sol–gel glass has been compared with that of a biocompatible non-resorbable soda–lime glass. Unlike the soda–lime glass, the sol–gel glass neither caused the inhibition of fibroblast growth nor elicited a marked inflammatory response by polymorphonuclear leukocytes, as demonstrated by chemiluminescence assay for reactive oxygen metabolites.     

Timetabling through Constrained Heuristic Search and Genetic Algorithms

Hybrid genetic algorithms are presented that use constrained heuristic search and genetic techniques for the timetabling problem (TP). The TP is an NP-hard problem for which a general polynomial time deterministic algorithm is not known. The paper describes the classification of constraints and the constraint ordering to obtain the minimization of backtracking and the maximization of parallelism. The school timetabling problem is discussed in detail as a case study. The genetic algorithm approach is particularly well suited to this kind of problem, since there exists an easy way to assess a good timetable, but not a well structured automatic technique for constructing it. So, a population of timetables is created that evolves toward the best solution. The evaluation function and the genetic operators are well separated from the domain-specific parts, such as the knowledge of the problem and the heuristics, i.e. from the timetable builder. The present paper illustrates an approach based on the hybridization of constrained heuristic search with novel genetic algorithm techniques. It compares favourably with known programs to solve decision problems under logic constraints. The cost of the new algorithm and the quality of the solutions obtained in significant experiments are reported.     

Characterization and Utilization of Ocean Quahog (Arctica islandica) Clam Juice as a Liquid and Dehydrated Flavoring Agent

Ocean quahog (Arctica islandica) juice produced from mechanical shucking operations was vacuum evaporated, freeze-dried, or spray-dried for use as a natural clam flavoring agent. The flavorings were judged‘equal or superior to several commercially available flavors when used in prepared dishes. Gas chromatographic profiles indicated high volatile concentrations in the effluent from the heat shocking and first washing process. Almost no volatiles were present in successive washings. The use of dextrins was not required since the natural chloride salts of potassium and sodium aided in obtaining powders of acceptable quality.     

Anthocyanins of Sunflower (Helianthus annuus)

The presence of anthocyanins in the achenes of some varieties of sunflower was ascertained for the first time. The two major pigments were identified as Pn-3-divanillylsambubioside and Cy-3-vanillylsambubioside. For two other pigments present in smaller quantities, a tentative identification awaiting confirmation was made and the constituents were identified. Traces were found of five other pigments for which chromatographic data are presented.