The Physical and Linear Viscoelastic Properties of Fresh Wet Foams Based on Egg White Proteins and Selected Hydrocolloids

The aim of this work was to evaluate the physicochemical properties of fresh foams based on egg white proteins, xanthan gum and gum Arabic. The distributions of the size of gas bubbles suspended in liquid were determined, as well as density and volume fraction of gas phase of the generated foams. Additionally, the viscoelastic properties in the linear range were measured, and the results were analyzed with the use of the fractional Zener model. It was shown, that foam supplementation with hydrocolloids considerably decreased their volume fraction of gas phase in comparison to pure egg white protein-based foams. Application of gum Arabic did not cause an increase in the size of foam bubbles when compared to pure white egg foam, whereas application of xanthan gum significantly decreased the size of the bubbles. Application of the fractional Zener model allowed to determine the relaxation times, their intensity in analyzed suspensions and also equilibrium module (G(e)). The increase in the concentration of xanthan gum resulted in the prolongation of the relaxation time and increased its intensity. Gum Arabic, when added, weakened the viscoelastic properties of the mixture as a viscoelastic solid

Effect of long-term proton pump inhibitor therapy on complete blood count parameters and selected trace elements : a pilot study

Introduction: Proton pump inhibitors (PPIs) are widely prescribed for several gastrointestinal conditions, often as long-term therapy. The effects of long-term PPI use have not been fully elucidated. Objectives: We aimed to determine the association between long-term PPI use and complete blood count parameters, particularly red blood cell (RBC) count, white blood cell (WBC) count, and hemoglobin concentrations, as well as serum levels of selected micronutrients such as selenium (Se), iron (Fe), copper (Cu), and zinc (Zn). Patients and methods: We enrolled 37 patients on long-term PPI therapy (mean [SD] age, 57.1 [15.4] years) and 30 healthy controls (mean [SD] age, 39.3 [11.8] years). In each group, complete blood count, and serum Fe levels were performed, and serum Cu, Zn, and Se levels were measured using atomic absorption spectrometry. Results: Red blood cell and WBC counts were lower in the PPI group compared with controls (mean [SD], 4.24 [0.55]×106/μl vs 4.7 [0.4]×106/μl; P <0.001 and 6.13 [1.44]×103/μl vs 7.3 [1.28]×103/μl; P <0.001, respectively). Hemoglobin and serum Fe concentrations were also lower in the PPI group (mean [SD], 12.5 [1.8] g/dl vs 14.3 [0.8] g/dl; P <0.001 and 16.3 [5.4] μmol/l vs 23.4 [2.7] μmol/l; P <0.001, respectively). Serum Zn and Cu concentrations were higher in PPI users than in controls. Conclusions: Long-term PPI therapy may reduce RBC and WBC counts as well as hemoglobin levels, leading to iron deficiency. It may also affect concentrations of some micronutrients, although the underlying mechanism of this association is not fully clear

<i>Plantago Ovata</i> Husk: An Investigation of Raw Aqueous Extracts. Osmotic, Hydrodynamic and Complex Rheological Characterisation

The aim of the study was to characterize raw aqueous extracts from Plantago ovata husk in terms of molecular chain mass, osmotic, hydrodynamic, and rheological properties. The raw extracts used in this study have not been yet investigated in the indicated research area. Determination of the molecular weight of the chains present in the extract was performed by gel permeation chromatography (GPC). Osmotic properties were characterized using membrane osmometry. Rheological properties were investigated via classical rotational rheology with normal force measurements, as well as less common but equally important measurements of extensional viscosity. Two types of chains with an average molecular mass of 200 and 1780 kDa were found. The values of the first virial coefficient (B2) indicate the predominance of biopolymer-biopolymer interactions. The hydrodynamic radius established at 25 and 30 °C was 74 and 67 nm, respectively, and lower than at 40 °C (>600 nm). The first critical concentration was determined: c*=0.11 g·dL−1. The dominance of negative normal force values resulting from the formation of a pseudo-gel structure of the heteroxylates was demonstrated. Extensional viscosity measurement results revealed that the studied extracts cannot be treated as simple shear-thinning fluids, as indicated by shear flow, but should be considered as viscoelastic fluids

Pressure Drop Method as a Useful Tool for Detecting Rheological Properties of Non-Newtonian Fluids during Flow

The aim of the research was to develop a pressure drop measuring method dedicated to fluids under real flow through a pipeline. The measurement system is a set of appropriately configured flow meter and pressure sensors installed on the pipeline. The pressure drop values detected on the measuring section are sufficient to clearly determine the rheological properties of the fluid. The measuring system used for the tests consisted of a screw pump, two pressure sensors and an electromagnetic flow meter. The length of the measuring section was 4.12 m, and the internal diameter of the pipeline was 0.026 m. To calibrate of the measuring system a glycerol was used. As a model fluid, a 1% water solution of xanthan gum was used and was subjected to the flow at following shear rate conditions: 5, 11, 17, 23, 29, 35, 41, 47, 53, 59, 65 s−1. The obtained raw experimental data included the pressure drop values and flow rate and they created full information about the fluid behavior during flow. According to the momentum balance equation, the rheological parameters of Ostwald de Waele model were estimated. The estimation procedure was carried out with the help of the Marquardt-Levenberg minimisation method. The same solutions simultaneously were tested with the help of a rotational rheometer. The data obtained from the pressure drop method were consistent with the results obtained from the rotational rheometer. The use of the pressure drop allows to determine the rheological properties of the non-newtonian fluids under the process conditions directly in the pipeline. In addition, it is possible to perform full rheological characteristics based on one flow rate under laminar conditions

Wpływ dodatku gumy ksantanowej i gumy guar na właściwości reologiczne pian wytwarzanych metodą ciągłą

The paper presents the effect of the addition of hydrocolloids – xanthan gum and guar gum – on the rheological properties of ovoalbumin-based food foams, produced by continuous method. The foaming was carried out in a column apparatus with additional aeration equipped with a paddle stirrer. In order to determine the rheological parameters, a hysteresis loop test was carried out. The results of the study were described using the Ostwald-de Waele equation. The effect of the addition of hydrocolloid on the rheological properties of the obtained foams was characterized, and the synergistic effects between the hydrocolloids used were described.Zbadano wpływ dodatku hydrokoloidów – gumy ksantanowej i gumy guar – na właściwości reologiczne wytwarzanych metodą ciągłą pian spożywczych na bazie albuminy jaja kurzego. Spienianie prowadzono w zaopatrzonym w mieszadło łopatkowe aparacie kolumnowym z dodatkowym napowietrzaniem. W celu określenia parametrów reologicznych wykonano test pętli histerezy. Wyniki badań opisano z zastosowaniem równania Ostwalda-de Waele. Scharakteryzowano wpływ dodatku hydrokoloidu na właściwości reologiczne otrzymanych pian oraz opisano efekty synergistyczne użytych hydrokoloidów