scholarly journals Migration of Hop Polyphenols in Beer Technology: Model Solution for Various Hopping Methods

2021 ◽  
pp. 628-638
Author(s):  
Marina Gernet ◽  
Irina Gribkova ◽  
Olga Borisenko ◽  
Maxim Zakharov ◽  
Varvara Zakharova
Keyword(s):  
Formation Rate ◽  
Influence Factors ◽  
Total Content ◽  
Production Method ◽  
Polyphenolic Compounds ◽  
Point Of View ◽  
Yeast Cells ◽  
Colloidal System ◽  
Migration Routes ◽  
Brewing Yeast

Introduction. The research featured the effect of various hopping conditions on the content of polyphenolic compounds associated with the extraction and biotransformation of hop compounds. This mechanism is responsible for uncharacteristic beer flavor in the traditional production method. The research objective was to study the migration routes, influence factors, and changes in the content of hop polyphenols in model experiments in order to reduce various factors in the production process chain. The experiment was important from the point of view of identifying the polyphenols contribution to the beer colloidal system. Study objects and methods. The study involved granulated aromatic hop of Tetnanger variety harvested in 2019, aqueous and 4% aqueous-alcoholic solutions simulating the wort and young beer liquid phase, and brewing yeast Sacharomyces cerevisiae of races Rh (lager) and Nottingham (ale). The work used the generally accepted methods for assessing the content of polyphenolic compounds. Results and discussion. The research established various factors that affected the migration of hop polyphenolic groups. The acidity effect on the polyphenol was established as follows: pH 4.4 contributed to a 12% greater isoxanthohumol accumulation, while pH 5.2 promoted a six times greater accumulation of anthocyanogens than pH 4.4. The total content of polyphenols during boiling was constant and correlated with the phenolic compound in different groups. The conditions of “dry” hopping, simulating the wort clarification in Wirpool, increased the dissolution of anthocyanogens by six times in comparison with kettle hopping, which was associated with the turbulent flow. The isoxanthohumol sorption and formation rate during “dry” hopping was established when modeling the maturation conditions for different temperatures, oxygen levels, and yeast races. A lower temperature (5°C) had a negative effect on the isoxanthohumol sorption. The quercetin content was found to be in the range of 0.9–2.0 mg/dm³ at 5°C and 0.8–4.7 mg/dm³ at 20°C, which determined the temperature effect on extraction during “dry” hopping. The presence of yeast cells in the medium promoted the quercetin accumulation: the quercetin content doubled at 5°C and quadrupled at 20°C compared with the control. The rutin content in the control increased for two days, and minor fluctuations in the content of yeast cells were 5.0 ÷ 7.4 mg/dm3. A comparative analysis of the simple phenolic acids and aldehydes amounts under “dry” hopping conditions showed a greater decrease in their concentration because they were involved in the yeast consumption and biotransformation processes. Conclusion. The research made it possible to establish the phenolic compounds in various groups of migration routes under the conditions of classical (kettle) and “dry” methods of hopping, as well as their dependence on such factors as medium acidity, stirring intensity, temperature, oxygen content, and yeast race. The sorption rates of the polyphenolic compounds were established as follows: absorption of isoxanthohumol was at its highest during the first day of “dry” hopping, and that of rutin – within two days, while quercetin was not absorbed at all. Therefore, an additional fermentation stage can be considered as the most expedient method of “dry” hopping.

Challenges in Hydrate Plug Prevention in Pipelines Seen Over the Lifetime of a Field

2009 ◽  
Author(s):  
Casper Hadsbjerg ◽  
Kristian Krejbjerg
Keyword(s):  
Oil And Gas ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Extended Period ◽  
Oil And Gas Industry ◽  
High Water ◽  
Point Of View ◽  
Field Development ◽  
Hydrate Plug ◽  
Subsea Pipelines

When the oil and gas industry explores subsea resources in remote areas and at high water depths, it is important to have advanced simulation tools available in order to assess the risks associated with these expensive projects. A major issue is whether hydrates will form when the hydrocarbons are transported to shore in subsea pipelines, since the formation of a hydrate plug might shut down a pipeline for an extended period of time, leading to severe losses. The industry practices a conservative approach to hydrate plug prevention, which is the addition of inhibitors to ensure that hydrates cannot form under pipeline pressure and temperature conditions. The addition of inhibitors to subsea pipelines is environmentally unfriendly and also a very costly procedure. Recent efforts has therefore focused on developing models for the hydrate formation rate (hydrate kinetics models), which can help determine how fast hydrates might form a plug in a pipeline, and whether the amount of inhibitor can be reduced without increasing the risk of hydrate plug formation. The main variables determining whether hydrate plugs form in a pipeline are: 1) the ratio of hydrocarbons to water, 2) the composition of the hydrocarbons, 3) the flowrates/flow regimes in the pipeline, 4) the amount of inhibitor in the system. Over the lifetime of a field, all 4 variables will change, and so will the challenge of hydrate plug prevention. This paper will examine the prevention of hydrate plugs in a pipeline, seen from a hydrate kinetics point of view. Different scenarios that can occur over the lifetime of a field will be investigated. Exemplified through a subsea field development, a pipeline simulator that considers hydrate formation in a pipeline is used to carry out a study to shed light on the most important issues to consider as conditions change. The information gained from this study can be used to cut down on inhibitor dosage, or possibly completely remove the need for inhibitor.

scholarly journals Comparison of Morphological, Antidiabetic and Antioxidant Properties of Goji Fruits

2020 ◽  
Vol 24 (1) ◽  
pp. 1-14
Author(s):  
Arleta Kruczek ◽  
Ireneusz Ochmian ◽  
Marcelina Krupa-Małkiewicz ◽  
Sabina Lachowicz
Keyword(s):  
Antioxidant Activity ◽  
Positive Impact ◽  
Antioxidant Properties ◽  
Total Content ◽  
Point Of View ◽  
Bioactive Substances ◽  
Health Promoting ◽  
Berry Fruits ◽  
North Western ◽  
Nitrite Content

AbstractThere is a growing public interest in fruits labeled as „superfood” (functional food). A “superfood” should have a high content of bioactive substances with a positive impact on human health. Seven different cultivars of goji berry fruits (Lycium chinense Mill.) grown in north-western Poland were evaluated for its physicochemical parameters, antidiabetic and antioxidant activity, and polyphenol content. The length of 1-year-old shoots ranged from 36 cm (‘Big Lifeberry’) to 82 cm (‘Korean Big’). Cultivars from the group of Big were characterized by the biggest fruits (17.3-24.2 mm) with the greatest weight of 100 fruits (96.7­122.1 g). ‘Big Lifeberry’ contained high amounts of L-ascorbic acid (408 mg 1000/g) and provitamin A (190 mg 1000/g) and showed high antidiabetic (α-amylase IC50=33.4 mg/mL; α-glucosidase IC50=9.9 mg/mL) and antioxidant activity (ABTS·+ 6.21 and FRAP 5.58 mmol T/100 g). ‘Big Lifeberry’ was also characterized by a high total content of polyphenols (43.64 mg 100/g). Furthermore, the nitrite content in all the cultivars tested was at a relatively low level. Among the examined cultivars, the most attractive one concerning the consumers’ point of view of the size, weight and high content of health-promoting compounds is ‘Big Lifeberry’.

scholarly journals High mass X-ray binaries as progenitors of gravitational wave sources

2018 ◽  
Vol 14 (S346) ◽  
pp. 417-425 ◽  
Author(s):  
Jakub Klencki ◽  
Gijs Nelemans
Keyword(s):  
Mass Transfer ◽  
Massive Star ◽  
Formation Rate ◽  
Point Of View ◽  
High Mass ◽  
Close Binary ◽  
X Ray ◽  
Orbital Periods ◽  
X Ray Binaries ◽  
Hubble Time

AbstractX-ray binaries with black hole (BH) accretors and massive star donors at short orbital periods of a few days can evolve into close binary BH (BBH) systems that merge within the Hubble time. From an observational point of view, upon the Roche-lobe overflow such systems will most likely appear as ultra-luminous X-ray sources (ULXs). To study this connection, we compute the mass transfer phase in systems with BH accretors and massive star donors (M > 15 Mʘ) at various orbital separations and metallicities. In the case of core-hydrogen and core-helium burning donors (cases A and C of mass transfer) we find the typical duration of super-Eddington mass transfer of up to 106 and 105 yr, with rates of 10−6 and 10−5Mʘ yr-1, respectively. Given that roughly 0.5 ULXs are found per unit of star formation rate, we estimate the rate of BBH mergers from stable mass transfer evolution to be at most 10 Gpc−3 yr−1.

scholarly journals Characterization of Simple and Double Yeast Cells Using Dielectrophoretic Force Measurement

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3813 ◽  
Author(s):  
Fernando-Juan García-Diego ◽  
Mario Rubio-Chavarría ◽  
Pedro Beltrán ◽  
Francisco J. Espinós
Keyword(s):  
Electric Fields ◽  
Force Measurement ◽  
Point Of View ◽  
Yeast Cells ◽  
Instrumental Method ◽  
Particle Characterization ◽  
Dielectrophoretic Force ◽  
Cell Velocity ◽  
First Time

Dielectrophoretic force is an electric force experienced by particles subjected to non-uniform electric fields. In recent years, plenty of dielectrophoretic force (DEP) applications have been developed. Most of these works have been centered on particle positioning and manipulation. DEP particle characterization has been left in the background. Likewise, these characterizations have studied the electric properties of particles from a qualitative point of view. This article focuses on the quantitative measurement of cells’ dielectric force, specifically yeast cells. The measures are obtained as the results of a theoretical model and an instrumental method, both of which are developed and described in the present article, based on a dielectrophoretic chamber made of two V-shaped placed electrodes. In this study, 845 cells were measured. For each one, six speeds were taken at different points in its trajectory. Furthermore, the chamber design is repeatable, and this was the first time that measurements of dielectrophoretic force and cell velocity for double yeast cells were accomplished. To validate the results obtained in the present research, the results have been compared with the dielectric properties of yeast cells collected in the pre-existing literature.

scholarly journals Production of highly ionized plasma by micro-dot array irradiation and its application to compact X-ray lasers

2002 ◽  
Vol 20 (1) ◽  
pp. 73-77 ◽  
Author(s):  
NAOHIRO YAMAGUCHI ◽  
CHIEMI FUJIKAWA ◽  
KAZUNOBU OKASAKA ◽  
TAMIO HARA
Keyword(s):  
Spatial Distribution ◽  
Spatial Structure ◽  
Pulse Train ◽  
Production Method ◽  
Point Of View ◽  
Rapid Expansion ◽  
Laser Generation ◽  
Plasma Production ◽  
X Ray ◽  
Laser Gain

A plasma production method using the irradiation of an array of small spots has been investigated from the point of view of soft X-ray laser generation in the recombining plasma scheme pumped by a pulse-train laser. The expansion geometry of highly ionized ions produced by the micro-dot array irradiation method has been measured and compared with that by a simple line irradiation. Spatial distribution of gain coefficients of the Li-like Al ion transition lines have also been measured for both irradiation methods. Highly ionized ions were observed to spread wider in the micro-dot array irradiation method. It is expected that rapid expansion and efficient cooling are achieved in plasmas produced by the micro-dot array irradiation method, which is consistent with the experimental results on the spatial structure of the X-ray laser gain region.

Dynamic Analysis of a Ferromagnetic Colloidal System

1999 ◽  
Vol 13 (14n16) ◽  
pp. 2085-2092 ◽  
Author(s):  
Hisao Morimoto ◽  
Toru Maekawa
Keyword(s):  
Magnetic Field ◽  
Dynamic Analysis ◽  
Brownian Dynamics ◽  
Scaling Law ◽  
Three Dimensional ◽  
Fractal Dimensions ◽  
Point Of View ◽  
Dynamic Scaling ◽  
Colloidal System ◽  
Dimensional System

We studied cluster structures formed in two- and three-dimensional magnetic fluid systems numerically. We developed a Brownian dynamics calculation method in which both the translational and rotational motions of ferromagnetic particles were taken into account. The cluster formations are analysed from the point of view of second order phase transition and the dependence of the cluster size on the temperature and magnetic field is investigated. The fractal dimensions were, respectively, 1.3 and 1.6 for the two- and three-dimensional systems in the absence of a magnetic field. On the other hand, the fractal dimension was very close to 1.0 for both two- and three-dimensional systems when the system was subjected to a magnetic field. The cluster-cluster aggregations are also investigated and the validity of the dynamic scaling law is examined. It has been found that the fractal dimensions obtained by the dynamic analysis coincide with those obtained by the analysis of the cluster structures. The critical exponents were 0.7 and 0.8 in the absence of a magnetic field and in a magnetic field, respectively, in the case of the two-dimensional system, and 1.2 and 0.8 in the case of the three-dimensional system for λ=12 where λ is the ratio of magnetic dipole energy to thermal energy.

scholarly journals Pre-purification of Plantago lanceolata extracts with biologically active compounds using yeast cells

2018 ◽  
Vol 11 (2) ◽  
pp. 163-169
Author(s):  
Vladimír Štefuca ◽  
Lukáš Rada ◽  
Alžbeta Chochulová ◽  
Michal Rosenberg
Keyword(s):  
Mass Transfer ◽  
Plantago Lanceolata ◽  
Packed Bed ◽  
Point Of View ◽  
Production Costs ◽  
Biologically Active ◽  
Effectiveness Factor ◽  
Packed Bed Reactor ◽  
Yeast Cells ◽  
Immobilized Cell

AbstractLeaves of the plantPlantago lanceolatacontain many economically interesting bioactive compounds, among them aucubin and catalpol are the most attractive. However, soluble saccharides passing to water extracts during isolation complicate chromatographic purification of these compounds. Their degradation by microbial cells transforming, for example, glucose, fructose, or sucrose to ethanol could bring important production costs savings and improved final product quality. It has been shown that the best saccharide degradation in extracts is achieved with theSaccharomyces cerevisiaecells. The cells were very active also in their immobilized form and they were able to completely remove glucose from the extract within four hours in a packed bed reactor combined with a stirring system with infinite medium recirculation.A simple mathematical model involving reaction kinetics and mass transfer limitations in the cell particles was proposed for the evaluation of cell effectiveness in their immobilized form in term of effectiveness factor. Values of the effectiveness factor calculated from the model were far below 1, indicating strong mass transfer limitations of the reaction. The model is suitable for optimization of preparation of immobilized cell particles, mainly from the point of view of cell charge in particles.

scholarly journals Functional value of a talgan made from sprouted wheat and barley

2021 ◽  
Vol 83 (1) ◽  
pp. 163-168
Author(s):  
A. V. Sumina ◽  
V. I. Polonskiy ◽  
T. M. Shaldaeva
Keyword(s):  
Total Content ◽  
Barley Grain ◽  
Climatic Conditions ◽  
Point Of View ◽  
Raw Material ◽  
National Product ◽  
Bidistilled Water ◽  
Functional Value ◽  
Germination Process ◽  
The Republic

The aim of this study was to analyze the total content of antioxidants (TCA) at different stages of production of the Khakass national product talgan, made from sprouted wheat and barley. Grain crops were grown on the territory of the Bey district of the Republic of Khakassia, which is characterized by favorable climatic conditions from the point of view of growing grain with an increased content of antioxidants. To determine the TCA value in the grain, two solvents were used – hot bidistilled water and 70% ethanol. The TCA measurement was performed on the device "Color Yauza-01-AA". Among all the grain samples studied, higher values were recorded when using hot bidistilled water as an eluent. It was found that the germination process did not reduce the taste qualities of the grain product. The value of the TCA in talgan, made on the basis of sprouted barley grain, was higher in comparison with wheat by 34%. The effect of increasing the level of TCA in the product in comparison with the initial raw material after the stage of grain germination in wheat and barley, respectively, by 1.5 and 2 times, and after the stages of roasting and grinding by 2 and 2.5 times. The value of FSA in bran exceeded that in the original grain by 44 and 65% for wheat and barley, respectively. Thus, as a result of the research, it was found that regardless of the studied crop (wheat, barley), the process of germination of grain is one of the effective ways to increase the value of TCA in the talgan product made on its basis.

Study on Strengthening Mechanism of Microscale Laser Shock Peening

2010 ◽  
Vol 431-432 ◽  
pp. 221-224
Author(s):  
Yu Jie Fan ◽  
Jian Zhong Zhou ◽  
Shu Huang ◽  
Min Wang ◽  
Yin Bo Zhu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Energy ◽  
Grain Boundary ◽  
Compressive Residual Stress ◽  
Influence Factors ◽  
Strengthening Mechanism ◽  
Point Of View ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

Microscale laser shock peening (μLSP) is a novel surface treating technology which oriented to microscale metal components in MEMS. Beneficial compressive residual stress is induced at the shocked region to improve the performance of microstructure based on wave-solid interactions. In this paper, the basic principle of μLSP and mechanism of wave-solid coupling were introduced, the influence factors on strengthening effects, such as micro-size effect, anisotropy, dislocation, stacking fault, grain boundary and surface energy were discussed from the microscopic point of view, the results provide theoretical guidance for further study.

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