Nucleation of branches in elastomeric polypropylene

The formation of a crosshatched morphology during crystallization of an isotactic polypropylene with low crystallinity is studied in detail. Here, a lamella seems to grow through another nearly perpendicular lamella that was crystallized before. The crystallization was observed with in situ scanning force microscopy with a temporal resolution of 3 min per image. After crystallization the volume structure was imaged by nanotomography. A detailed scheme for the nucleation of branches is proposed.     

Untersuchungen zum Transfer pharmakologisch wirksamer Substanzen aus der Nutztierhaltung in Porree und Weißkohl

Investigation on the transfer of pharmacologically active substances used in animal husbandry into leek and cabbage. The potential of leek and cabbage for uptake of highly prescribed veterinary drugs (antibiotics) was tested in hydroponically grown plants. For this purpose the antibiotics sulfadiazine (SFD), enrofloxacine (ENR), tetracycline (TC), chlortetracycline (CTC) and monensine (MON) were chosen. A further aim was to gain data on the situation of vegetables grown in agricultural practise with regard to antibiotic residues. The evident effects of the antibiotics on plants grown hydroponically (each antibiotic was administered at 5 μmol/l nutrient solution) were greatly different: With regard to leek there were no visible effects (MON, SFD), a weak bleaching of the younger leaf sections (CTC), and strong effects of ENR. The (phytotoxic) effects of antibiotics on cabbage were much more distinct. CTC caused a yellowing of the plant vasculature in cabbage. MON induced lesions on some leaves and finally led to leaf wilting. With administration of ENR a nearly complete bleaching of young leaves was observed. Using LC-MS/MS-methods (low-resolution and high-resolution MS) the administered antibiotics, as well as conversion products and metabolites, were separately identified and quantified in various organs of leek (roots, young and old sections of leaves) and cabbage (roots, stalks, young and old leaves). Depending on the type of antibiotic, vegetable species, and plant organ, the detected concentrations of antibiotic residues comprised several orders of magnitude ranging from μg/kg to mg/kg of fresh weight (fw). The highest concentrations of antibiotics were found in roots of both vegetable species: CTC and TC were detected at approximately 10 mg/kg fw in cabbage roots and at approximately 20 mg/kg fw in leek roots and ENR was determined at approximately 12 mg/kg fw in cabbage roots. Low amounts of ENR were metabolised to ciprofloxacine (CIP). ENR occurred at similar concentrations of approximately 7 mg/kg fw in roots and old leaves of cabbage, indicating a high transport rate of this antibiotic in the cabbage plant. In stalks, young and old leaves of cabbage and in young and old leaf sections of leek all administered antibiotics were detected. Within these antibiotics, ENR and CTC and their conversion products, e. g. demeclocycline (DMC) and TC, occurred at the highest concentrations. SFD and MON were found in considerably lower concentrations (<100 μg/kg fw). The results of our experiments in hydroponic cultures, using defined concentrations of antibiotics in the nutrient solution, evidently demonstrate that cabbage and leek have a very high potential for uptake of a number of veterinary antibiotic drugs, especially for tetracycline and ENR.     

Germin-like protein Cit s 1 and profilin Cit s 2 are major allergens in orange (Citrus sinensis) fruits

Oranges are clinically relevant allergenic foods. To date, orange allergens have not been characterized in detail. The study is aimed at analyzing the sensitization profile in orange-sensitized subjects with and without clinical allergy, and to identify orange allergens. Fifty-six sensitized subjects with self-reported reactions to orange were grouped into reactors (anaphylaxis or multiple episodes of immediate reactions and/or positive challenge tests) and non-reactors (negative open food challenge tests). Allergens were characterized by IgE immunoblotting, N-terminal sequencing, IgE-inhibition assays, and mediator release assays were performed to determine the allergenic potency of orange profilin. Of 56 subjects, 23 were classified as orange allergic showing mainly an oral allergy syndrome. Of 23 subjects classified as orange allergic, 22 were sensitized to profilin, Cit s 2. In patients with mono-sensitization to profilin in vitro histamine releases up to 75% from basophils were induced using orange extract and purified plant profilins. Of the allergic patients 78% were sensitized to germin-like protein, Cit s 1. Both allergens showed retained IgE reactivity in heat-processed orange juice. Interestingly, subjects with and without clinical allergy showed a comparable sensitization profile. Profilin and germin-like proteins are major orange allergens. The potential clinical relevance of orange profilin was indicated by its strong capacity to release histamine from basophils. However, a predominant sensitization to both allergens in subjects without symptoms also indicates a high frequency of clinically insignificant sensitization.     

Magnetic Behaviour of O2 Confined in Nanopores

The static susceptibility of solid oxygen condensed into nanoporous matrices is measured as a function of temperature and pore diameter. The drastic changes of the qualitative behaviour are interpreted as a cross-over from three- to one-dimensional behaviour.     

Prevalence of Yersinia enterocolitica in fattening pigs

The prevalence of pathogenic Yersinia enterocolitica in pig herds was monitored during six trials (at four different farrow-to-finisher farms). Samples were taken throughout the whole rearing period from birth of the piglets to the final fattening stage, and different samples were taken from these pigs during the slaughter process. Environmental samples also were evaluated to identify potential sources of on-farm infection. Y. enterocolitica was isolated using irgasan-ticarcillin-potassium chlorate broth enrichment and cefsulodin-irgasan-novobiocin agar culture. Colonies were identified using bio- and serotyping methods and by PCR assay. Pathogenic Y. enterocolitica were not isolated from fecal samples from piglets and weaners. The only fecal samples positive for Y. enterocolitica were obtained during the fattening stage. The prevalence of Y. enterocolitica in fattening pig herds ranged between 0 and 65.4%. Y. enterocolitica isolates were detected at the abattoir in 38.4% of the tonsils, in 3.8% of the ileocecal lymph nodes, on 0.3% of the carcass surfaces before chilling, and on 0% of the carcass surfaces after chilling. Almost all isolates belonged to bioserotype 4/O:3. Only one strain was identified as O:9. All isolates contained the ail gene. The yopT gene was found in 99.1% of the farm isolates but in only 76.6% of the isolates found at the abattoir from the corresponding carcasses. Although a direct link between porcine isolates and human infection has not been demonstrated, the similarity of the bioserotypes in infected pigs and humans and the presence of virulence factors in porcine isolates should encourage further studies to determine the risk of transmission of Y. enterocolitica to humans from pigs and pork products.     

Improved mapping of in-mouth creaminess of semi-solid dairy products by combining rheology,particle size,and tribology data

The effects of fat, protein, and casein to whey protein ratio on lubricating properties of stirred yogurt were determined and the relation of those to the sensory properties graininess, viscosity, and creaminess was assessed. Results demonstrated decreased friction effects with increasing fat and protein level, and decreasing proportion of whey protein. The predictive ability of in-mouth viscosity (r² = 0.91) and in-mouth creaminess (r² = 0.97) could be improved by combined assessments of rheological, particle size, and tribological characteristics. Graininess was not affected by friction data. To this end, the applicability of generated models has been tested. This study depicts a better understanding of the key drivers for creaminess and enables food manufacturers to develop fat-reduced dairy products without compromise on sensory properties.     

Water quality and taste sensitivity for basic tastes and metallic sensation

The aim of the study was to investigate the influence of water quality on taste sensitivity for basic tastes and metallic sensation. To familiarize subjects with sensory analysis, they were asked to recognize tastes, distinguish between different concentrations of basic tastes, and realize their own taste sensitivity. The International Standard ISO 3972 describes a set of tests to measure taste sensitivity. A “neutral, tasteless, still and odourless water, preferably of known hardness” is recommended for preparing the dilutions and for rinsing the mouth. The standard also recommends a series of dilutions for acid (citric acid), bitter (caffeine), salty (sodium chloride), sweet (sucrose), umami (monosodium glutamate) and metallic (iron(II)sulfate). The question arises if water quality affects taste sensitivity.MethodsTwenty-three female subjects (mean age: 22), who were recruited at the University of Applied Sciences Hamburg, Faculty of Life Sciences, were tested. Deionized water, spring water and tap water were used for taste dilutions. In each experiment, subjects were initially familiarized with the basic tastes.ResultsIn comparison to taste thresholds in spring water, the recognition thresholds are higher using tap water, and lower using deionized water. When using deionized water, sour was detected by all subjects at the lowest concentrations. Iron(II)sulfate could best be matched to metallic sensation in deionized water. Results indicate that taste sensitivity is influenced by water quality.     

Correlations of ingredients with sensory attributes in green beans and peas under different storage conditions

The total ascorbic acid contents and the antioxidant capacity in green beans and in peas were measured during deep-frozen storage and compared to storage at 4 °C and 20 °C. In green beans only, the flavonols quercetin and kaempferol were measured. The results were correlated with sensory attributes which were evaluated at the same storage stages. The total ascorbic acid content is a good parameter for the storage time of both vegetables and showed, for peas, a positive correlation with the attribute “sweet taste” and a negative correlation with the attribute “musty” odour. The total ascorbic acid content of green beans was positively correlated with a “squeaky” texture and negatively with a “musty” taste. The flavonol content and the antioxidant capacity were more stable during the storage process and showed less correlation with sensory attributes.     

Sensorische Beurteilung des Bittergeschmacks von Amarogentin und Austauschm?glichkeiten gegen Chinin in Erfrischungsgetr?nken

Zusammenfassung In der vorliegenden Arbeit wurde mit Hilfe sensorischer Beurteilung der Einfluß von Saccharose, Anhydrocitronensäure und Limettearoma auf die Bitternote von Amarogentin, einem natürlichen Bitterstoff der Enzianwurzel, im Hinblick auf Austauschmöglichkeiten gegen Chinin in Erfrischungsgetränken, untersucht. Um die Austauschmöglichkeiten von Chinin durch Amarogentin beurteilen zu können, wurden die unterschiedlichen Bitterverläufe von Amarogentin und Chinin sensorisch beurteilt. Die Versuche ergaben, daß identische Bitternoten für Amarogentin und Chinin nicht zu erreichen waren. Darüber hinaus erwies sich Amarogentin gegenüber Konzentrationsänderungen von Citronensäure und Saccharose im Vergleich zu Chinin als wesentlich empfindlicher. Änderungen der Amarogentin-Konzentration hingegen hatten kaum Auswirkungen auf die Bitternote. Für Chinin ergaben sich ausschließlich Änderungen in der Intensität, nicht in der Bitternote. Amarogentin zeichnete sich durch eine abgerundete und reine Bitternote ohne störenden Nachgeschmack aus.

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Sensory evaluation of the bitter taste of amarogentin and the feasibility of its exchange for quinine in soft drinks1. Influence of sucrose and anhydrous citric acid

Summary The influence of sucrose, anhydrous citric acid and lemon flavour on the bitter taste of amarogentin, a natural bitter-tasting component of gentian root, has been investigated. The investigation, based on sensory evaluation, is aimed at evaluating the possibility of exchanging amarogentin for quinine in soft drinks. To do this the different states of bitter taste of quinine and amarogentin had to be noted in a particular way. The tests showed the possibility of obtaining identical bitter tastes from quinine and amarogentin. Additionally, amarogentin proved to be much more sensitive to changes in concentration of anhydrous citric acid and sucrose than quinine. In contrast, different amarogentin concentrations did not produce remarkable effects on the bitter taste. With quinine, the sensory tests showed a change in intensity of the bitter taste with concentration. Amarogentin produced a well-rounded and pure bitter taste without any after-taste which could impair the quality.

     

Untersuchungen zur passivierenden Wirkung organischer Oxydationsmittel auf Eisen in neutralen und schwach sauren Lösungen. 2. Mitteilung: Aromatische Nitroverbindungen

Investigation into the passivation effect of organic oxidizing agents on the corrosion of iron in neutral weakly acid solutions. 2nd communication: Aromatic nitrocompounds The present communication is con cerned with the corrosion inhibiting properties of aromatic nitro compounds on iron in the neutral range. Nitrobenzenes (m-nitroaniline, p-chloronitrobenzene, M-nitrobenzoic acid, ethylester, p-nitrobenzaldehyde, p-nitrobenzonitrile) in concentrations between 0,25 · 10^?2 and 0.5 · 1^?2 Mole/litre act as stimulators in airsaturated 20% methanol of pH 6.8. Their combination with a 20% methanolic boric acid/borate solution of pH 6.8 – which, as such, only maintains passivity, yields passivating systems. From these examples as well as from others involving known inhibitors it appears highly probable that the prassivation of iron by corrosion inhibiting addition in the neutral range, too, requires a communication of oxidizing and non-oxidizing agents (combination principle )able to lower the critical passivation current density.