Analysis of bread flour constituents

Summary Organic compounds present in minute quantities are responsible for bread flavor profile. Organic acids, alcohols, esters and carbonyl compounds have been identified and estimated, quantitatively, by use of paper, column and vapor-phase chromatography. Because of the minute quantities of most organic flavor constituents, some system of extraction and concentration must be employed for successful analysis. Separation into classes and concentration is best accomplished by formation of derivatives. Developing solvents, carrier system, and techniques of chromatography must be carefully selected for each group of compounds. Success in the analysis of bread flavor constituents has been significant in recent years because of the development of chromatography techniques.

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Zusammenfassung Die Geschmackseigenschaften von Brot werden durch in sehr geringen Mengen vorhandene organische Verbindungen bedingt. Mittels Papier-, Säulen- und Gaschromatographie wurden organische Säuren, Alkohole, Ester und Karbonylverbindungen ermittelt und mengenmäßig bestimmt. Die äußerst geringen Mengen der Mehrzahl der organischen Geschmackskomponenten können nur mit einer Methode, die Extraktion und Konzentration umfaßt, erfolgreich analysiert werden. Diese Trennung in Gruppen und Konzentration wird am besten über die Bildung von Sekundärverbindungen erreicht. Hierbei muß für jede Gruppe von Komponenten eine sehr sorgfältige Auswahl der Entwicklungslösungen, der Vektorsysteme und der chromatographischen Technik getroffen werden. Die bedeutenden Fortschritte der chromatographischen Techniken der letzten Jahre sind der Grund für die Erfolge auf dem Gebiete der Analyse der Geschmackskomponenten von Brot.

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Résumé Des composés organiques, présents en très faible quantités, régissent le profil de saveur du pain. Des acides organiques, des alcools, des esters et des composés carbonyliques ont été identifiés, et évalués, quantitativement par chromatographie sur papier, sur colonne, et en phase vapeur. Du fait des faibles quantités de la plupart des composants organiques de saveur, un système d'extraction et de concentration doit être utilisé pour réussir les analyses. La séparation en classes et la concentration peut être obtenue de façon la meilleure par formation de dérivés. Les solvants de développement, les systèmes vecteurs, et les techniques de chromatographie, doivent être soigneusement selectionnés pour chaque groupe de composants. Les réussites dans le domaine de l'analyse des composants de la saveur du pain ont été significatives ces dernières années, du fait du développement des techniques chromatographiques,

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with 4 figs.

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Contribution no. 424, Department of Flour and Feed Milling Industries, Kansas State Agricultural Experiment Station, Manhattan, Kansas, U.S.A.     

Experiments with Cyperus rotundus L. III. Seasonal variations in growth

Nutgrass tubers were planted in pots on thirteen occasions at 4-weekly intervals, and growth and development followed by sampling at 5-day intervals from 10 to 45 days after planting. Growth rates, final shoot numbers, dry weights and rhizome lengths, and new tuber production were highest in plantings made 1 and 29 March and 26 April. Correlation coefficients suggested that mean daylength during growth was a major factor influencing growth and development, but mean temperature appeared to be important in determining new tuber size and the proportion of dry-matter as new tubers. Shoot number appears to be a reliable guide to rhizome and tuber production.     

Tetanus in the Horse: A Review of 20 Cases (1970 to 1990)

The case records of 20 horses with tetanus referred to the Ontario Veterinary College-Veterinary Teaching Hospital between 1970 and 1990 were reviewed. The fatality rate was 75%. There was a strong association with previous vaccination and survival ( P = .03). Most of the animals had been injured an average of 9 days (range 2 to 21 days) prior to development of clinical signs. Hyperesthesia and prolapse of the third eyelid were the most common clinical signs. Treatment regimens varied during hospitalization; however, all horses received parenteral penicillin, tranquilizers, tetanus toxoid, and antitoxin. Five of the nonsurviving animals were given intrathecal tetanus antitoxin. One animal had seizures as a complication of intrathecal treatment. The prognosis was best for horses that (1) had been vaccinated prior to the injury, (2) responded to the phenothiazine tranquilizers, and (3) did not rapidly (over 24 to 48 hours) become recumbent. Considering the species susceptibility, potential for contaminated wounds, and the increased survival of vaccinated horses, yearly revaccination is recommended.     

钾、磷与肉种鸡猝死综合症

现代肉种鸡生产中 ,为预防猝死综合症( Sudden death syndrom,SDS)所需要的磷与钾量远高于其他生产过程所需量。建议 2 0～ 2 8周龄肉种鸡日粮至少应含钾 0 .65 % ,可消化磷0 .40 %。在过去 1年中 ,许多营养学家就肉种鸡的磷需要量作过综述。 Reddy( 2 0 0 1 )指出 ,0 .1 %的非植酸磷能保持肉种鸡最大生产性能和种蛋最大孵化率 ,而要维持最大骨骼强度 ,这个数字应为0 .2 %或 0 .3%。Wilson建议用非植酸磷代替植酸磷。 SDS多发于成年肉种鸡群中 ,尤其是那些大型肉种鸡品系 ,目前 ,大型肉种鸡约占世界肉鸡市场的 5 0 %。 SDS在 2 0世纪 8…     

Mitral Stenosis in 15 Dogs

Mitral stenosis was diagnosed in 15 young to middle-aged dogs. There were 5 Newfoundlands and 4 bull terriers affected, suggesting a breed predisposition for this disorder. Clinical signs included cough, dyspnea, exercise intolerance, and syncope. Soft left apical diastolic murmurs were heard only in 4 dogs, whereas 8 dogs had systolic murmurs characteristic of mitral regurgitation. Left atrial enlargement was the most prominent radiographic feature. Left-sided congestive heart failure was detected by radiographs in 11 dogs within 1 year of diagnosis. Electrocardiographic abnormalities varied among dogs and included atrial and ventricular enlargement, as well as atrial and ventricular arrhythmias. Abnormalities on M-mode and two-dimensional echocardiograms included abnormal diastolic motion of the mitral valve characterized by decreased leaflet separation, valve doming, concordant motion of the parietal mitral valve leaflet, and a decreased E-to-F slope. Increased mitral valve inflow velocities and prolonged pressure half-times were detected by Doppler echocardiography. Cardiac catheterization, performed in 8 dogs, documented a diastolic pressure gradient between the left atrial, pulmonary capillary wedge, or pulmonary artery diastolic pressures and the left ventricular diastolic pressure. Necropsy showed mitral stenosis caused by thickened, fused mitral valve leaflets in 5 dogs and a supramitral ring in another dog. The outcome in affected dogs was poor; 9 of 15 dogs were euthanatized or died by 2 1/2 years of age.     

A method to detect rabbit neutrophil phagocytosis of Pasteurella multocida

A method was developed to detect neutrophil phagocytosis of bacteria by determining whether neutrophil-associated bacteria were intra- or extracellular. Neutrophils were treated with 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate hydrochloride to inhibit degranulation and, consequently, killing of bacteria. Treated neutrophils and opsonized Pasteurella multocida were combined. Following phagocytosis, the suspensions were centrifuged and the pellets were washed to remove non-cell-associated bacteria. The pellets were resuspended and heparin was added to prevent further phagocytosis. Samples were removed, and the number of viable bacteria was determined by a dilution and plate count technique. Streptomycin, an antibiotic that is poorly taken up by neutrophils, was added to kill extracellular bacteria, and the suspensions were incubated for 20 minutes at 37 C, and samples were removed again and bacterial numbers were determined. Percentage killing of bacteria by streptomycin was calculated. Phagocytosed bacteria were protected from the bactericidal action of streptomycin.     

Green-light supplementation for enhanced lettuce growth under red- and blue-light-emitting diodes

Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.     

Evidence for occurrence of an organophosphate-resistant type of acetylcholinesterase in strains of sea lice (Lepeophtheirus salmonis Krøyer)

Acetylcholinesterase (AChE) is the target of a major pesticide family, the organophosphates, which were extensively used as control agents of sea lice on farmed salmonids in the early 1990s. From the mid‐1990s the organophosphates dichlorvos and azamethiphos were seriously compromised by the development of resistance. AChE insensitive to organophosphate chemotherapeutants has been identified as a major resistance mechanism in numerous arthropod species, and in this study, target‐site resistance was confirmed in the crustacean Lepeophtheirus salmonis Krøyer isolated from several fish‐farming areas in Norway and Canada. A bimolecular rate assay demonstrated the presence of two AChE enzymes with different sensitivities towards azamethiphos, one that was rapidly inactivated and one that was very slowly inactivated. To our knowledge this is the first report of target‐site resistance towards organophosphates in a third class of arthropods, the Crustacea. Copyright © 2004 Society of Chemical Industry