An enzymic method for differentiating thawed and fresh fish fillets

The specific activities of the lysosomal enzymes α-glucosidase and β-N-acetylglucosaminidase were determined in press juices and extracts from fresh and frozen/thawed fillets of cod, saithe, red fish and haddock. For each of the two enzymes it was found that the press juice/extract activity ratio increased following the freezing/thawing process (six to nine times for αglucosidase and three to five times for β-N-acetylglucosaminidase).     

The photoinduced charge transfer mechanism in aligned and unaligned carbon nanotubes

Using time-resolved reflectivity measurements on unaligned and aligned bundled single-wall carbon nanotubes with a pump energy of 1.55 eV, quasi-resonant with the second Van Hove singularity of semiconducting tubes, a positive sign of the transient reflectivity is detected in unaligned nanotubes. In contrast a negative sign is detected in aligned nanotubes. This discovery addresses a long-standing question showing that in unaligned nanotubes the stronger intertube interactions favor the formation of short-lived free charge carriers in semiconducting tubes. A detailed analysis of the transient reflectivity spectral response shows that the free carriers in the photo-excited state of semiconducting tubes move towards metallic tubes in about 400 fs.     

New insights into the thermal desorption of the 2LiNH2 + KBH4 + LiH mixture

In situ two-dimensional synchrotron X-ray powder diffraction investigation combined with Rietveld method data analysis were performed in order to yield a complete and quantitative phases structure evolution of the polycrystalline mixture 2LiNH₂ + KBH₄ + LiH during H₂ desorption. While a first-principles, purely thermodynamics approach of the system predicted a single dehydrogenation step reaction at relatively low temperatures, it is assessed experimentally that the reaction occurs in two steps with first the formation of Li₂NH at ca. 230 °C due to the reaction between LiNH₂ and LiH plus hydrogen and ammonia evolution, followed by an additional reaction of the resulting phases with KBH₄ at 360 °C, which releases hydrogen and leads to the formation of the monoclinic and tetragonal Li₃BN₂ polymorphs. Besides pointing out possible limits of a purely thermodynamics approach inevitably relying exact knowledge of experimental quantities, it is concluded that before assuming it viable for on-board vehicle use, additional stoichiometries may be worth of investigation in order to assess any existence of lower hydrogen desorption temperature of such system.     

Recovery and concentration of phenolic compounds in blood orange juice by membrane operations

Cross-flow ultrafiltration (UF) and osmotic distillation (OD) were implemented on laboratory scale to obtain formulations of interest for food and/or pharmaceutical industry starting from the blood orange juice produced in the Calabria region. The freshly squeezed juice, after a depectinization step, was submitted to an UF process in order to recover natural antioxidants, such as hydroxycinnamic acids, hydroxybenzoic acids, flavanones, flavan-3-ols, and anthocyanins. The UF permeate, with an initial total soluble solids (TSS) content of 10.5°Brix, was concentrated by OD up to a final concentration of 61.4°Brix.     

Simultaneous determination of type A,B and D trichothecenes and their occurrence in cereals and cereal products

A sensitive LC–MS/MS method for the simultaneous determination of type A, B and D trichothecenes in cereals is presented. The limits of detection ranged between 0.1 and 0.7 µg kg^?1 for all analytes. The method was applied to 289 representatively drawn samples of wheat, rye and oat products. Ninety-four percent of the wheat samples (n = 130), 95% of the rye samples (n = 61) and 100% of the oat samples (n = 98) were contaminated with the type A trichothecenes T-2 and HT-2 toxin. Median levels of T-2/HT-2 (sum of the toxins) were 0.91, 0.53 and 8.2 µg kg^?1, respectively. Highest levels were found in wheat bran (24 µg kg^?1), rye kernels (3.1 µg kg^?1) and oat flakes (85 µg kg^?1). All wheat and rye samples and 75% of the oat samples were contaminated with the type B trichothecene deoxynivalenol. Median levels of this toxin were 23, 15 and 0.53 µg kg^?1, respectively. Highest levels were found in wheat bran (1160 µg kg^?1), rye kernels (288 µg kg^?1) and oat flakes (55 µg kg^?1). The type B trichothecene nivalenol was detected in 67% of the wheat samples, in 3% of the rye samples and in 24% of the oat samples with highest levels in wheat bran (96 µg kg^?1), rye kernels (1.8 µg kg^?1) and in oat flakes (17 µg kg^?1), respectively. Levels of other type A and B trichothecenes played a minor role, although the rates of contamination were often high. Neither macrocyclic type D trichothecenes (satratoxin G and H, verrucarin A, roridin A) nor diacetylverrucarol and verrucarol (type A trichothecenes), were detected in any of the samples.     

Modeling the performance of coated LPG tanks engulfed in fires

The improvement of passive fire protection of storage vessels is a key factor to enhance safety among the LPG distribution chain. A thermal and mechanical model based on finite elements simulations was developed to assess the behaviour of full size tanks used for LPG storage and transportation in fire engulfment scenarios. The model was validated by experimental results. A specific analysis of the performance of four different reference coating materials was then carried out, also defining specific key performance indicators (KPIs) to assess design safety margins in near-miss simulations. The results confirmed the wide influence of coating application on the expected vessel time to failure due to fire engulfment. A quite different performance of the alternative coating materials was evidenced. General correlations were developed among the vessel time to failure and the effective coating thickness in full engulfment scenarios, providing a preliminary assessment of the coating thickness required to prevent tank rupture for a given time lapse. The KPIs defined allowed the assessment of the available safety margins in the reference scenarios analyzed and of the robustness of thermal protection design.     

Symposium review: The importance of the ruminal epithelial barrier for a healthy and productive cow

The stratified squamous ruminal epithelium is the main site for absorption of key nutrients (e.g., short-chain fatty acids; SCFA) and electrolytes (e.g., sodium and magnesium). The absorptive function has to be highly selective to prevent simultaneous entry of microbes and toxins from the rumen into the blood. As such, epithelial absorption is primarily transcellular, whereas the paracellular pathway appears rather tightly sealed. A network of tight junction (claudin-1, claudin-4, and occludin) and tight junction-associated proteins (e.g., zonula occludens) accomplishes the latter. When microbial fermentation activity is high such as with highly fermentable diets, rumen epithelial functions are often challenged by acidity, high osmolarity, toxins (e.g., endotoxin and histamine), and immune mediators (inflammatory mediators and cytokines) released during local and systemic inflammation. Epithelial damage by low pH in combination with high luminal SCFA concentrations is not immediately reversible and may initially aggravate upon return to physiological pH. In contrast, barrier opening upon hyperosmolarity is acutely transient. The initial insults set by luminal acidity and SCFA and the increasing concentrations of microbial-associated molecular patterns such as lipopolysaccharides are key factors that trigger inflammation not only in the rumen but also in the hindgut (cecum and colon), which reach out to the liver and other organs, causing systemic inflammation. Low feed intake during parturition, transportation, heat stress, or disease is the second most relevant challenge for the ruminal epithelial barrier. The barrier opening is usually only transient and quickly restored upon refeeding. Due to a rapid, dose-dependent, and prolonged decrease in absorption capacity for SCFA, however, any feed restriction increases the odds for postrestriction subacute ruminal acidosis. Inflammation due to acidosis can be alleviated by supplemental thiamine, yeasts, and plant bioactive (phytogenic) compounds. Butyrate is used in weaning calves to support ruminal barrier development; however, excess butyrate may promote hyperkeratosis, parakeratosis, and epithelial injury in the fully developed rumen of adult cows. Further research is needed to enhance the understanding of the various factors that counteract barrier impairment and help barrier restoration during acidogenic feeding, especially when concurring with unavoidable periods of feed restriction.     

Sensorische Analyse, Malat- und Saccharosegehalt und Fruchtfleischfestigkeit verschiedener Apfelsorten

Zusammenfassung Neben einer ausführlichen sensorischen Beurteilung der Frühsorte Jamba, der mittelspäten Sorten Holsteiner Cox und Roter Holsteiner Cox sowie der späten Sorte Gloster wurden parallel dazu der Malat- und Saccharosegehalt und die Fruchtfleischfestigkeit bestimmt. Die Korrelation dieser chemisch-physikalischen Parameter mit der Bewertung des Geschmacks und der Fruchtfleischstruktur sollte die Frage klären, ob eine Qualitätsaussage unter Umgehung der sensorischen Beurteilung möglich ist. Durch Vergleich ergab sich, daß für alle untersuchten Sorten der Malat- und/oder Saccharosegehalt wenig über die geschmacklichen Qualität der Früchte aussagt. Engere Beziehungen traten zwischen den Parametern sensorische Fruchtfleischbewertung und Festigkeit auf, wo bei einem Festigkeitswert von 5–5,3 kp/cm² und mehr das entsprechende senorische Urteil nicht schlechter als mittelmäßig ausfiel.

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Sensory evaluation, content of malate and sucrose, and fruit firmness of different apple varieties

Summary Parallel to a detailed sensory evaluation of the apple varieties Jamba, Holsteiner Cox, Red Holsteiner Cox and Gloster the content of malate and sucrose and fruit flesh firmness were measured. Comparisons between chemical and physical parameters and the sensory evaluation of taste and fruit flesh structure were performed to see, if apple quality can be determined without sensory assessment. The results for all samples show that content of malate and sucrose means little in relation to fruit taste. Recommendations for an optimum storage period could not be made. There was a closer relationship between sensory fruit flesh assessment and flesh firmness with a firmness of 5–5,3 kp/cm² or higher sensory evaluation was not worse than fair.

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Teil der Dissertation Mast, Kiel 1982     

The State of the Art of Piezo1 Channels in Skeletal Muscle Regeneration

Piezo1 channels are highly mechanically-activated cation channels that can sense and transduce the mechanical stimuli into physiological signals in different tissues including skeletal muscle. In this focused review, we summarize the emerging evidence of Piezo1 channel-mediated effects in the physiology of skeletal muscle, with a particular focus on the role of Piezo1 in controlling myogenic precursor activity and skeletal muscle regeneration and vascularization. The disclosed effects reported by pharmacological activation of Piezo1 channels with the selective agonist Yoda1 indicate a potential impact of Piezo1 channel activity in skeletal muscle regeneration, which is disrupted in various muscular pathological states. All findings reported so far agree with the idea that Piezo1 channels represent a novel, powerful molecular target to develop new therapeutic strategies for preventing or ameliorating skeletal muscle disorders characterized by an impairment of tissue regenerative potential.     

Lipidomic Approaches to Study HDL Metabolism in Patients with Central Obesity Diagnosed with Metabolic Syndrome

The metabolic syndrome (MetS) is a cluster of cardiovascular risk factors characterised by central obesity, atherogenic dyslipidaemia, and changes in the circulating lipidome; the underlying mechanisms that lead to this lipid remodelling have only been partially elucidated. This study used an integrated “omics” approach (untargeted whole serum lipidomics, targeted proteomics, and lipoprotein lipidomics) to study lipoprotein remodelling and HDL composition in subjects with central obesity diagnosed with MetS (vs. controls). Compared with healthy subjects, MetS patients showed higher free fatty acids, diglycerides, phosphatidylcholines, and triglycerides, particularly those enriched in products of de novo lipogenesis. On the other hand, the “lysophosphatidylcholines to phosphatidylcholines” and “cholesteryl ester to free cholesterol” ratios were reduced, pointing to a lower activity of lecithin cholesterol acyltransferase (LCAT) in MetS; LCAT activity (directly measured and predicted by lipidomic ratios) was positively correlated with high-density lipoprotein cholesterol (HDL-C) and negatively correlated with body mass index (BMI) and insulin resistance. Moreover, many phosphatidylcholines and sphingomyelins were significantly lower in the HDL of MetS patients and strongly correlated with BMI and clinical metabolic parameters. These results suggest that MetS is associated with an impairment of phospholipid metabolism in HDL, partially led by LCAT, and associated with obesity and underlying insulin resistance. This study proposes a candidate strategy to use integrated “omics” approaches to gain mechanistic insights into lipoprotein remodelling, thus deepening the knowledge regarding the molecular basis of the association between MetS and atherosclerosis.