Ultrasound-Assisted Extraction and Characterization of Polyphenols from Apple Pomace,Functional Ingredients for Beef Burger Fortification

Currently, there is an increasing interest to valorise agri-food waste containing bioactive compounds with potential health benefits. In this paper, the recovery of functional molecules from apple pomace, the most abundant by-product of the apple processing industry, was carried out by ultrasound-assisted extraction (UAE) on fresh and freeze-dried samples. UAE extract, obtained by double extraction of freeze-dried apple pomace, was subjected to chromatographic and spectrophotometric characterization. It showed good levels of total phenol content, high antioxidant activity, and interesting antioxidant compounds (quercetin derivatives, chlorogenic acid, phloridzin). Subsequently, freeze-dried apple pomace, containing 40.19% of dietary fibre, was used as a fortifying agent for beef burgers (4% and 8%). The results concerning colour and sensory analysis of the fortified products were graded even better than the control (0%). The improved fibre and phenol content, together with the neutral flavour, represent the most interesting characteristics of fortified burgers. The results confirm that UAE was a successful technique for extracting phenol compounds and that the addition of apple pomace represents a valid approach to increase the health properties and palatability of beef burgers, including for consumers who do not like meat.     

The Dysregulation of the Renin–Angiotensin System in COVID-19 Studied by Serum Proteomics: Angiotensinogen Increases with Disease Severity

(1) Background: ACE and CPN serum activity correlated with disease severity in an earlier study of 45 hospitalized COVID-19 patients. The serum protein profile was investigated in the same cohort here to shed more light on the involvement of the renin–angiotensin system (RAS). (2) Methods: High-definition mass spectrometry-based protein expression analysis was performed, followed by multivariate statistical and network analyses. (3) Results: The protein profiles of hospitalized patients (HoP) differed significantly from those of convalescent and healthy probands. Surprisingly, HoP samples separated into six groups according to their protein profiles: group (G) 1 represented the youngest and the least afflicted patients, and G6 the oldest and critically ill patients. At least two major pathophysiological schemes were indicated based on differing involvement of the kallikrein-kinin system (KKS), the RAS and complement activation. The serum angiotensinogen concentration increased with disease severity. (4) Conclusions: The important role of the RAS in the response to COVID-19 infection was substantiated, but other pathways such as the KKS, plasminogen activation and complement activation influence the systemic response to the infection.     

Production of Primary Metabolites by Rhizopus stolonifer,Causal Agent of Almond Hull Rot Disease

Species in the fungal genus Rhizopus are able to convert simple sugars into primary metabolites such as fumaric acid, lactic acid, citric acid, and, to a lesser extent, malic acid in the presence of specific carbon and nitrogen sources. This ability has been linked to plant pathogenicity. Rhizopus stolonifer causes hull rot disease in almonds, symptoms of which have been previously associated with the fungus’s production of fumaric acid. Six isolates of R. stolonifer taken from infected almond hulls were grown in artificial media amended with one of four carbon sources (glucose, fructose, sucrose, and xylose) and two nitrogen sources (asparagine and ammonium sulphate) chosen based on almond hull composition and used in industry. Proton nuclear magnetic resonance (¹H NMR)–based metabolomics identified that R. stolonifer could metabolise glucose, fructose, sucrose, and to a lesser extent xylose, and both nitrogen sources, to produce three metabolites, i.e., fumaric acid, lactic acid, and ethanol, under in vitro conditions. Sugar metabolisation and acid production were significantly influenced by sugar source and isolates, with five isolates depleting glucose most rapidly, followed by fructose, sucrose, and then xylose. The maximum amounts of metabolites were produced when glucose was the carbon source, with fumaric acid produced in higher amounts than lactic acid. Isolate 19A–0069, however, preferred sucrose as the carbon source, and Isolate 19A–0030 produced higher amounts of lactic acid than fumaric acid. This is the first report, to our knowledge, of R. stolonifer producing lactic acid in preference to fumaric acid. Additionally, R. stolonifer isolate 19–0030 was inoculated into Nonpareil almond fruit on trees grown under high– and low–nitrogen and water treatments, and hull compositions of infected and uninfected fruit were analysed using ¹H NMR–based metabolomics. Glucose and asparagine content of uninfected hulls was influenced by the nitrogen and water treatments provided to the trees, being higher in the high–nitrogen and water treatments. In infected hulls, glucose and fructose were significantly reduced but not sucrose or xylose. Large amounts of both fumaric and lactic acid were produced, particularly under high–nitrogen treatments. Moreover, almond shoots placed in dilute solutions of fumaric acid or lactic acid developed leaf symptoms very similar to the ‘strike’ symptoms seen in hull rot disease in the field, suggesting both acids are involved in causing disease.     

Shape-persistent macrocycles: building blocks for complex organic and polymeric architectures

Alkyl- and Oligostyrene substituents were attached to shape-persistent macrocycles based on a phenyl-ethynyl backbone. In good solvents for both the rigid core and the flexible corona no aggregation occurred. Whereas, addition of a solvent that selectively solubilizes the corona induced a solvophobic aggregation. For alkyl substituted rings the experimental data were described by a monomer-dimer equilibrium. In contrast, the oligostyrene substituted rings formed more expanded aggregates which were investigated by scattering and by imaging methods. The superstructures are consequently described as hollow supramolecular cylindrical brushes.     

NMR-Bildgebung und Materialforschung

Magnetic resonance imaging (MRI) is a powerful tool in medical diagnostics. But this technique of nuclear magnetic resonance (NMR) ist also receiving increasing attention in materials science because it is non-invasive and because of the abundance of different contrast parameters which reflect the molecular properties of the samples. For instance, distributions in microscopic molecular re-orientations as well as macroscopic coherent motion can be imaged by appropriate techniques. Applications of both aspects of MRI are reported by examples of images from elastomers, skin, and velocity profiles. In addition, a new method for investigations of surfacenear volume elements of arbitraril shaped samples is shown.     

Surface modification of polypropylene: Hydrophilic finishing with carbohydrates

Conversion of hydrophobic polypropylene surfaces to hydrophilic, water wettable surfaces by adsorption of amphiphilic carbohydrates (“surfactant immobilization”) as well as by covalent bonding of sucrose residues via azid photolysis (“photochemical immobilization”) was investigated. Improvement of surface hydrophilicity was determined by contact angle measurements and application of special test inks for polyolefines.     

Hydrogen autoignition at pressures above the second explosion limit (0.6–4.0 MPa)

The investigation of high-pressure autoignition of combustible mixtures is of importance in providing both practical information in the design of combustion systems and fundamental measurements to verify and develop chemical kinetic models. The autoignition characteristics of hydrogen-oxygen mixtures at low pressures have been explored extensively, whereas few measurements have been made at high pressures. The present measurements extend the range of pressures up to 4 MPa, where few measurements have yet been reported. Using a rapid compression machine equipped with a specially designed piston head, hydrogen autoignition pressure traces were measured at pressures above the second explosion limit (p=0.6–4 MPa, T=950–1050 K). The measured pressure records show a more gradual pressure increase during induction time in this regime than in the low-pressure regime, indicating that the energy release becomes significant at conditions over the second explosion limit. By comparing the measurements and a thermodynamic model which incorporates the heat transfer and energy release, a modified reaction rate constant for H₂O₂+H=HO₂+H₂, one of the most important reactions for hydrogen oxidation at high pressure, and the reaction with the largest uncertainty, is suggested in this work as k₁₇=2.3 . 10¹³exp(−4000/T) cm³/mol-s. The modeled pressure history with the modified reaction rate agrees well with the measured values during the induction period over the range of conditions tested. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 385–406, 1998     

Gastric Cancer Pre-Stage Detection and Early Diagnosis of Gastritis Using Serum Protein Signatures

Background: A gastric cancer (GC) diagnosis relies on histopathology. Endoscopy rates are increasing. Helicobacter pylori infection is a major GC risk factor. In an effort to elucidate abundant blood biomarkers, and potentially reduce the number of diagnostic surgical interventions, we investigated sera and biopsies from a cohort of 219 H. pylori positive and negative patients diagnosed with GC, gastritis, and ulcers. This allowed the comparative investigation of the different gastroduodenal diseases, and the exclusion of protein changes resulting from bacterial infection or inflammation of the gastric mucosa when searching for GC-dependent proteins. Methods: High-definition mass spectrometry-based expression analysis of tryptically digested proteins was performed, followed by multivariate statistical and network analyses for the different disease groups, with respect to H. pylori infection status. Significantly regulated proteins differing more than two-fold between groups were shortlisted, and their role in gastritis and GC discussed. Results: We present data of comparative protein analyses of biopsies and sera from patients suffering from mild to advanced gastritis, ulcers, and early to advanced GC, in conjunction with a wealth of metadata, clinical information, histopathological evaluation, and H. pylori infection status. We used samples from pre-malignant stages to extract prospective serum markers for early-stage GC, and present a 29-protein marker panel containing, amongst others, integrin β-6 and glutathione peroxidase. Furthermore, ten serum markers specific for advanced GC, independent of H. pylori infection, are provided. They include CRP, protein S100A9, and kallistatin. The majority of these proteins were previously discussed in the context of cancer or GC. In addition, we detected hypoalbuminemia and increased fibrinogen serum levels in gastritis. Conclusion: Two protein panels were suggested for the development of multiplex tests for GC serum diagnostics. For most of the elements contained in these panels, individual commercial tests are available. Thus, we envision the design of multi-protein assays, incorporating several to all of the panel members, in order to gain a level of specificity that cannot be achieved by testing a single protein alone. As their development and validation will take time, gastritis diagnosis based on the fibrinogen to albumin serum ratio may be a quick way forward. Its determination at the primary/secondary care level for early diagnosis could significantly reduce the number of referrals to endoscopy. Preventive measures are in high demand. The protein marker panels presented in this work will contribute to improved GC diagnostics, once they have been transferred from a research result to a practical tool.