Utilisation of free and protein-bound methionine sulphoxide by the chicken

The biological availability of free and protein-bound methionine sulphoxide (MSO) was examined in nine growth experiments with chickens. The source of protein-bound MSO was fish meals oxidised with hydrogen peroxide. Bound MSO in oxidised fish meals was equally well utilised by the chicken as was bound methionine in unoxidised fish meals when the meals were the sole protein sources in the diet. When used as supplements to a low-methionine diet, oxidised fish meals were slightly less well utilised than L -methionine and unoxidised meals at the highest supplementation levels. At a low level there was no difference. Free L -MSO was less well utilised than free L -methionine when added to a soya bean meal diet and when used in purified diets. In the latter cystine was found to improve the utilisation of MSO. High levels of MSO were found in muscle extracts of chickens even when no MSO was present in their diet.     

Conducting Domain Walls in Lithium Niobate Single Crystals

Ferroic materials play an increasingly important role in novel (nano)electronic devices. Recently, research on domain walls (DWs) receives a big boost by the discovery of DW conductivity (DWC) in BiFeO₃ and Pb(Zr_xTi_1‐x)O₃ ferroic thin films. Here, it is demonstrated that DWC is not restricted to thin films, but equally applies to millimeter‐thick wide‐bandgap, ferroic single crystals, such as LiNbO₃. In this material transport along DWs can be switched by super‐bandgap illumination and tuned by engineering the tilting angle of DWs with respect to the polar axis. The results are consistently obtained using conductive atomic force microscopy to locally map the DWC and macroscopic contacts, thereby in addition investigating the temperature dependence, DW transport activation energies, and relaxation behavior.     

Multifunctional Magnetic Optical Sensor Particles with Tunable Sizes for Monitoring Metabolic Parameters and as a Basis for Nanotherapeutics

Magnetic optical sensor particles with multifunctional cores and shells are synthesized via a facile nanoprecipitation method and the subsequent modification of the particle shell. The hydrophobic particle core includes optical oxygen indicators, a light harvesting system, photosensitizers, and magnetic nanoparticles. Further functionalities are introduced by modifying the shell with enzymes, antibodies, multiple layers of polyelectrolytes, stimuli‐responsive polymers, and luminescent indicator dyes. The hydrodynamic diameter is tunable by varying different precipitation parameters.     

Bioactivity and metabolism of trans-resveratrol orally administered to Wistar rats

The purpose of this study was to investigate the implications of selected chemopreventive parameters and metabolic conversion of resveratrol in vivo. In two 8-week long feeding experiments with rats, a low-resveratrol diet containing 50 mg resveratrol per kg body weight (bw) and day and a high-resveratrol diet with 300 mg per kg bw and day were administered. For chemopreventive evaluation selected phase I and phase II enzymes of the biotransformation system, the total antioxidant activity, and the vitamin E status of the animals were determined. The level of resveratrol and its metabolites in the feces, urine, plasma, liver, and kidneys was identified and quantitated by high-performance liquid chromatography-diode array detection (HPLC-DAD) using synthesized resveratrol conjugate standards. Feeding of different dosages of resveratrol revealed no effect on the different chemopreventive parameters, except for the total antioxidant activity, which was elevated in plasma by 19% after feeding 50 mg resveratrol per kg bw and day. The formation of trans-resveratrol-3-sulfate, trans-resveratrol-4'-sulfate, trans-resveratrol-3,5-disulfate, trans-resveratrol-3,4'-disulfate, trans-resveratrol-3,4',5-trisulfate, trans-resveratrol-3-O-beta-D-glucuronide, and resveratrol aglycone was detected by HPLC analysis, depending on the biological material. Total resveratrol recovery in urine and feces of rats fed on 50 mg resveratrol per kg bw and day was 15% and 13%, respectively. For rats fed the higher dosage of 300 mg resveratrol per kg bw and day recovery was 54% and 17%, respectively. This is the first study performed with synthesized standards of relevant resveratrol conjugates. The lack of effect on the chemopreventive parameters is probably due to the formation of various resveratrol conjugates reducing its bioavailability in the rat.     

Particle Size of Whole Meal Rye Bread does not Affect the Digestibility of Macro-Nutrients and Non-Starch Polysaccharides and the Energy Value of Dietary Fibre in Humans

The effect of particle size of whole meal rye bread on the apparent digestibility of macro-nutrients, non-starch polysaccharides (NSP) and energy, the energy value of rye NSP and on faecal weight was studied in balance experiments in seven young women. The whole meal breads were prepared from one single batch of rye milled to two different particle sizes (coarse bread: 50% of particles >2 mm, 90% >1 mm; fine bread: 86% of particles <0·5 mm, 58% <0·2 mm). Two diets containing either coarse (350 g day⁻¹) or fine (377 g day⁻¹) whole meal bread and a low fibre control diet were consumed for 3 weeks each in a 3×3 cross-over design. Relative to the low fibre control diet, digestibility of protein, NSP and energy was significantly lower for the diets containing the whole meal breads. Digestibility of fat was the same for all diets. Partial digestible energy value for each g of NSP from coarse and fine whole meal rye bread was calculated to be −3±7 and 1±5 kJ, respectively. There were no differences between coarse and fine whole meal rye bread in the effects on the parameters measured with the exception on faecal wet weight, which was higher for the coarse bread diet.     

Comparison of the relative quantities of aroma compounds found in fresh apricot (Prunus armeniaca) from six different varieties

Summary The volatile components of fresh apricot (Prunus armeniaca) were isolated by vacuum distillation and fractionated on a silica gel column. Analysis by gaschromatography coupled with mass spectrometry led to the identification of 82 compounds, 60 of which were found for the first time in this fruit. Six varieties, cultivated in the south of France were compared for their firmness, acidity, sweetness and for their content of 56 volatile components. Precoce de Tyrinthe was the least aromatic variety, but produced fruits very early in the season. Palsteyn gave acidic but rather aromatic fruits. Moniqui possessed large but perishable fruits with flowery aroma due to the presence of terpenic ketones. Rouge du Roussillon contained all the identified volatile compounds and possessed a pleasant aroma. Polonais contained many C₆-compounds with herbaceous notes and Bergeron was rich in lactones but poor in terpenic alcohols.

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Über die Gehalte an Aromakomponenten von sechs Aprikosensorten (Prunus armeniaca)

Zusammenfassung Die flüchtigen Aromastoffe von Aprikosen (Prunus armeniaca) wurden durch Vakuumdestillation und anschließende chromatographische Vortrennung und Kieselgel isoliert. Mit kombinierter gaschromatographischer Analyse wurden 82 Komponenten, davon 60 zum ersten Mal, identifiziert. Die Gehalte an Zucker, Säuren und 56 Aromakomponenten von 6 französischen Aprikosensorten wurden miteinander verglichen. Die Sorte Precoce de Tyrinthe ist wenig aromatisch aber frühreif, die Sorte Moniqui trägt große Früchte mit einem Blumenaroma von Ketonen, während Rouge du Roussillon viele Komponenten und das angenehmste Aroma besitzt. Die Sorte Polonais zeichnet sich durch den höchsten Gehalt an C₆-Komponenten und ein krautartiges Aroma aus. Die Sorte Bergeron ist reich an Lactonen, jedoch arm an Terpenalkoholen.

     

Use of the selective agar medium CREAD for monitoring the level of airborne spoilage moulds in cheese production

It was investigated if a selective medium for common cheese spoiling moulds (CREAD) could give more relevant information than a general mould medium in hygienic air-sampling in cheese factories. A total of 126 air-samples were taken in six Nordic cheese factories using the general mould medium DG18 and CREAD. The level and genera of air-borne mould was determined. Identification to species-level was performed for a selection of samples. In five cheese factories the mycobiota was dominated by Penicillium spp. and in one cheese factory by Cladosporium spp. The concentration of air-borne moulds varied between the cheese factories ranging from 1 to 270 cfu/m3 on DG18 with a median value of 17. The number of mould colonies was in general lower at CREAD. Identification indicated that CREAD supported growth of common spoilage moulds for cheese, such as Penicillium palitans and P. commune. The mycobiota on DG18 also consisted of moulds not commonly associated with spoilage of cheese, such as Cladosporium spp., P. brevicompactum and P. chrysogenum. Contamination of cheese with mould is periodically a problem in production of semi-hard cheese and the level of air-borne mould is therefore routinely monitored in cheese factories. A clear correlation between the total number of moulds in air and mould growth on products is not always found. The conclusion from the investigation is that it is recommended to use a selective medium for cheese spoilage moulds, such as CREAD in hygienic monitoring.