scholarly journals STUDY OF BETULIN STABILITY BY ELECTROKINETIC POTENTIAL DETERMINATION

2021 ◽  
pp. 63-67
Author(s):  
Г.И. Мальцев
Keyword(s):  
Aqueous Solution ◽  
Zeta Potential ◽  
Food Industry ◽  
Colloidal Particle ◽  
Electrokinetic Potential ◽  
Energy Costs ◽  
Particle Charge ◽  
The Stability ◽  
Time And Energy ◽  
Biological Actions

Исследование стабильности бетулина методом определения электрокинетического потенциала. На сегодняшний день бетулин интересен в области медицины, косметики и пищевой промышленности, ведь он обладает огромным спектром биологических действий. Из него можно получить производные, которые, в свою очередь, имеют определенное хорошо выраженное действие и используются для производства различных медикаментов. И чтобы интенсифицировать процесс очистки и фильтрования бетулина для экономии времени и затрат на энергию, необходимо узнать его заряд коллоидной частицы и стабильность в водном растворе. Для этого было проведено определение электрокинетического потенциала. Найден ξ-потенциал бетулина в водном растворе, который показал, что с увеличением концентрации водного раствора бетулина вероятность разрушения дисперсии и возможность образования хлопьев при добавлении коагулянта или флогулянта повышаются. Определен заряд поверхности коллоидной частицы бетулина. Investigation of the stability of betulin by the method of determining the electrokinetic potential.Today betulin is interesting in the field of medicine, cosmetics and food industry, because it has a huge range of biological actions. From it, you can get derivatives, which in turn have a certain well-defined effect and are used for the production of various medicines. In order to intensify the process of cleaning and filtering betulin to save time and energy costs, we need to know its colloidal particle charge and stability in an aqueous solution. To do this, we conducted a method for determining the electrokinetic potential. we determined the zeta potential of betulin in an aqueous solution, which showed that with an increase in the concentration of betulin in water, the probability of destruction of the dispersion and the possibility of flocculation when adding a coagulant or flogulant increases. We determined the surface charge of a colloidal betulin particle.

Fabrication and Stability of CoAl2O4 Ceramic Pigment for 3D Printing

2017 ◽  
Vol 898 ◽  
pp. 1935-1939 ◽  
Author(s):  
Yuan Song ◽  
Yuan Lin Zheng ◽  
Yu Fei Tang ◽  
Hai Bing Yang
Keyword(s):  
Solid Solution ◽  
Aqueous Solution ◽  
3D Printing ◽  
Zeta Potential ◽  
Spinel Structure ◽  
Sol Gel ◽  
Ceramic Pigment ◽  
Ceramic Pigments ◽  
Oxide Solid Solution ◽  
The Stability

Ceramic pigment is the key component of the ink color in the 3D printing process of ceramic products. The color performance and stability of ceramic pigments after calcination still need to be improved. In the present study the cobalt aluminate (CoAl2O4) ceramic pigment powders were fabricated by sol-gel method. The effects of fabrication processes on color properties of CoAl2O4 ceramic pigments were investigated. The compositions and morphologies of CoAl2O4 ceramic pigment powders were characterized. The stability of CoAl2O4 ceramic pigments was discussed. The results showed that the CoAl2O4 ceramic pigment with high chroma was obtained at calcination temperature of 1200°C and the Co/Al ratio is 1:3. The Zeta potential of the fabricated CoAl2O4 ceramic pigment powders in aqueous solution was-66.2 mV, which represented good dispersion stability. The chroma and saturation of the CoAl2O4 ceramic pigment increased owing to that the oxide solid solution in the spinel structure increased after being sintered at 1300 oC.

Study of the Effects of SiO2 Nanoparticles Concentration on the TiO2 Nanoparticles Suspensions Stabilization

2017 ◽  
Vol 899 ◽  
pp. 232-236
Author(s):  
Elizabeth Mendes de Oliveira ◽  
Mara Carolina do Carmo Paresque ◽  
Leonardo Martins da Silva ◽  
Luiz Carlos Rolim Lopes ◽  
Jose Adilson de Castro
Keyword(s):  
Zeta Potential ◽  
Special Interest ◽  
Food Industry ◽  
Nanoparticle Tracking Analysis ◽  
Treatment Processes ◽  
Nanoparticles Concentration ◽  
Industrial Use ◽  
The Stability ◽  
Nanoparticles Suspension ◽  
Strong Ability

TiO2 nanoparticles (NPTiO2) suspensions are in several ecosystems and residue treatment processes or disposal systems due to their large industrial use and handling. The interactions of the NPTiO2 with NPSiO2 have special interest due to their strong ability to maintain high TiO2 nanoparticles concentration in suspension and promote nanoparticles clustering. These characteristics are used either in cleaning systems or in production of nanoparticles solution for several applications in the food industry or medicine. In this study, suspensions of NPTiO2 and NPSiO2 are synthetized and their stabilizations are discussed. A base TiO2 nanoparticles suspension was synthetized and the initial concentrations of SiO2 nanoparticles (NPSiO2) were changed in order to determine the effects of presence of SiO2 nanoparticles on the stabilization and clustering size. Zeta potential and concentrations measurements were carried out throughout the time and correlated with the initial concentrations of the base suspensions. In this study, the concentrations, zeta potential and pH are measured to estimate the stability of the suspensions. The clustering size, obtained by nanoparticle tracking analysis (NTA), are also monitored and discussed. Results of column soil experiments are discussed and compared under similar conditions with literature data.

The Influence of Heating and Photosensitization on the Stability of Lutein- Loaded Lipid-Core Nanocapsules

2020 ◽  
Vol 16 (9) ◽  
pp. 1340-1345
Author(s):  
Aelson A.S. Brum ◽  
Médelin M. da Silva ◽  
Priscilla P. dos Santos ◽  
Allana V.S. Brasil ◽  
Karina Paese ◽  
...  
Keyword(s):  
Activation Energy ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Zeta Potential ◽  
Singlet Oxygen ◽  
Food Industry ◽  
Entrapment Efficiency ◽  
Average Diameter ◽  
Lipid Core ◽  
The Stability

Background: Despite lutein is unstable in light, heat, and oxygen, it is a good quencher of singlet oxygen. The present study evaluated the stability of lutein (92% of purity) in Lipid-core Nanocapsules (Lutein-LNC) prepared through interfacial deposition of preformed polymer, during photosensitization (5-25°C) and heating (70-90°C). Methods: The Lutein-LNC was characterized and presented a polydispersity index of 0.11, an average diameter of 191 nm (dynamic light scattering), zeta potential of -9.14 mV and entrapment efficiency of 100%. Results and Discussion: During photosensitization and heating, Lutein-LNC exhibited activation Energy (Ea) of 24.67 kcal/mol and 9.96 kcal/mol, respectively, and these values of Lutein-LNC were higher than free lutein values, reported in other studies for both experiments. Conclusion: The results obtained in this study suggested that nanotechnology can improve the stability of lutein for future applications in the food industry.

An Experimental Investigation on Thermal Conductivity and Viscosity of Graphene doped CNTs /TiO2 Nanofluid

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
A.M. Zetty Akhtar ◽  
M.M. Rahman ◽  
K. Kadirgama ◽  
M.A. Maleque
Keyword(s):  
Thermal Conductivity ◽  
Zeta Potential ◽  
Base Fluid ◽  
Minimum Quantity Lubrication ◽  
Cutting Fluid ◽  
Cutting Zone ◽  
Observation Method ◽  
The Stability ◽  
The Relationship ◽  
Zeta Potential Analysis

This paper presents the findings of the stability, thermal conductivity and viscosity of CNTs (doped with 10 wt% graphene)- TiO2 hybrid nanofluids under various concentrations. While the usage of cutting fluid in machining operation is necessary for removing the heat generated at the cutting zone, the excessive use of it could lead to environmental and health issue to the operators. Therefore, the minimum quantity lubrication (MQL) to replace the conventional flooding was introduced. The MQL method minimises the usage of cutting fluid as a step to achieve a cleaner environment and sustainable machining. However, the low thermal conductivity of the base fluid in the MQL system caused the insufficient removal of heat generated in the cutting zone. Addition of nanoparticles to the base fluid was then introduced to enhance the performance of cutting fluids. The ethylene glycol used as the base fluid, titanium dioxide (TiO2) and carbon nanotubes (CNTs) nanoparticle mixed to produce nanofluids with concentrations of 0.02 to 0.1 wt.% with an interval of 0.02 wt%. The mixing ratio of TiO2: CNTs was 90:10 and ratio of SDBS (surfactant): CNTs was 10:1. The stability of nanofluid checked using observation method and zeta potential analysis. The thermal conductivity and viscosity of suspension were measured at a temperature range between 30˚C to 70˚C (with increment of 10˚C) to determine the relationship between concentration and temperature on nanofluid’s thermal physical properties. Based on the results obtained, zeta potential value for nanofluid range from -50 to -70 mV indicates a good stability of the suspension. Thermal conductivity of nanofluid increases as an increase of temperature and enhancement ratio is within the range of 1.51 to 4.53 compared to the base fluid. Meanwhile, the viscosity of nanofluid shows decrements with an increase of the temperature remarks significant advantage in pumping power. The developed nanofluid in this study found to be stable with enhanced thermal conductivity and decrease in viscosity, which at once make it possible to be use as nanolubricant in machining operation.

REMOVAL OF HEAVY METAL Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II) IONS FROM AQUEOUS SOLUTION BY MENTHA PIPERITA EXTRACT

2020 ◽  
pp. 15-20
Author(s):  
Ersin Yucel ◽  
Mine Yucel
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
High Efficiency ◽  
Correlation Coefficients ◽  
Langmuir Model ◽  
Mentha Piperita ◽  
Freundlich Model ◽  
Biosorption Capacity ◽  
Peppermint Extract ◽  
The Stability

In this study, the usage of the peppermint (Mentha piperita) for extracting the metal ions [Mg (II), Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II)] that exist at water was investigated. In order to analyze the stability properties, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms were used at removing the metal ions and the highest correlation coefficients (R2) were obtained at Langmuir isotherm. Therefore, it is seen that the Langmuir model is more proper than the Freundlich model. However, it was found that the correlation coefficients of removing Ni and Cd is higher at Freundlich model than Langmuir and low at Dubinin-Radushkevich isotherm. It is established that the biosorption amount increase depends on the increase of biosorbent and it can be achieved high efficiency (95%) even with small amount (0.6 mg, peppermint extract) at lead ions. It is also determined that the peppermint extracted that is used at this study shows high biosorption capacity for metal ions and can be used for immobilization of metals from polluted areas.

Insights into Potent Therapeutical Antileukemic Agent L-glutaminase Enzyme Under Solid-state Fermentation: A Review

2020 ◽  
Vol 21 (3) ◽  
pp. 211-220 ◽  
Author(s):  
Chandrasai Potla Durthi ◽  
Madhuri Pola ◽  
Satish Babu Rajulapati ◽  
Anand Kishore Kola
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Food Industry ◽  
Energy Requirement ◽  
Production Studies ◽  
Wide Range ◽  
Hybridoma Technology ◽  
Bacteria And Fungi ◽  
The Stability ◽  
Glutaminase Activity

Aim & objective: To review the applications and production studies of reported antileukemic drug L-glutaminase under Solid-state Fermentation (SSF). Overview: An amidohydrolase that gained economic importance because of its wide range of applications in the pharmaceutical industry, as well as the food industry, is L-glutaminase. The medical applications utilized it as an anti-tumor agent as well as an antiretroviral agent. L-glutaminase is employed in the food industry as an acrylamide degradation agent, as a flavor enhancer and for the synthesis of theanine. Another application includes its use in hybridoma technology as a biosensing agent. Because of its diverse applications, scientists are now focusing on enhancing the production and optimization of L-glutaminase from various sources by both Solid-state Fermentation (SSF) and submerged fermentation studies. Of both types of fermentation processes, SSF has gained importance because of its minimal cost and energy requirement. L-glutaminase can be produced by SSF from both bacteria and fungi. Single-factor studies, as well as multi-level optimization studies, were employed to enhance L-glutaminase production. It was concluded that L-glutaminase activity achieved by SSF was 1690 U/g using wheat bran and Bengal gram husk by applying feed-forward artificial neural network and genetic algorithm. The highest L-glutaminase activity achieved under SSF was 3300 U/gds from Bacillus sp., by mixture design. Purification and kinetics studies were also reported to find the molecular weight as well as the stability of L-glutaminase. Conclusion: The current review is focused on the production of L-glutaminase by SSF from both bacteria and fungi. It was concluded from reported literature that optimization studies enhanced L-glutaminase production. Researchers have also confirmed antileukemic and anti-tumor properties of the purified L-glutaminase on various cell lines.

scholarly journals Anthocyanins Recovered from Agri-Food By-Products Using Innovative Processes: Trends, Challenges, and Perspectives for Their Application in Food Systems

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2632
Author(s):  
Henrique Silvano Arruda ◽  
Eric Keven Silva ◽  
Nayara Macêdo Peixoto Araujo ◽  
Gustavo Araujo Pereira ◽  
Glaucia Maria Pastore ◽  
...  
Keyword(s):  
Food Systems ◽  
Food Industry ◽  
Biological Properties ◽  
Extraction Techniques ◽  
Naturally Occurring ◽  
Current Review ◽  
Natural Colorants ◽  
Conventional Extraction ◽  
The Stability ◽  
By Products

Anthocyanins are naturally occurring phytochemicals that have attracted growing interest from consumers and the food industry due to their multiple biological properties and technological applications. Nevertheless, conventional extraction techniques based on thermal technologies can compromise both the recovery and stability of anthocyanins, reducing their global yield and/or limiting their application in food systems. The current review provides an overview of the main innovative processes (e.g., pulsed electric field, microwave, and ultrasound) used to recover anthocyanins from agri-food waste/by-products and the mechanisms involved in anthocyanin extraction and their impacts on the stability of these compounds. Moreover, trends and perspectives of anthocyanins’ applications in food systems, such as antioxidants, natural colorants, preservatives, and active and smart packaging components, are addressed. Challenges behind anthocyanin implementation in food systems are displayed and potential solutions to overcome these drawbacks are proposed.

scholarly journals The Effect of pH and Storage Temperature on the Stability of Emulsions Stabilized by Rapeseed Proteins

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1657
Author(s):  
Karolina Östbring ◽  
María Matos ◽  
Ali Marefati ◽  
Cecilia Ahlström ◽  
Gemma Gutiérrez
Keyword(s):  
Zeta Potential ◽  
Storage Temperature ◽  
Emulsion Stability ◽  
Press Cake ◽  
Strong Impact ◽  
Soy Lecithin ◽  
Rapeseed Protein ◽  
Rapeseed Proteins ◽  
Precipitation Ph ◽  
The Stability

Rapeseed press cake (RPC), the by-product of rapeseed oil production, contains proteins with emulsifying properties, which can be used in food applications. Proteins from industrially produced RPC were extracted at pH 10.5 and precipitated at pH 3 (RPP3) and 6.5 (RPP6.5). Emulsions were formulated at three different pHs (pH 3, 4.5, and 6) with soy lecithin as control, and were stored for six months at either 4 °C or 30 °C. Zeta potential and droplet size distribution were analyzed prior to incubation, and emulsion stability was assessed over time by a Turbiscan instrument. Soy lecithin had significantly larger zeta potential (−49 mV to 66 mV) than rapeseed protein (−19 mV to 20 mV). Rapeseed protein stabilized emulsions with smaller droplets at pH close to neutral, whereas soy lecithin was more efficient at lower pHs. Emulsions stabilized by rapeseed protein had higher stability during storage compared to emulsions prepared by soy lecithin. Precipitation pH during the protein extraction process had a strong impact on the emulsion stability. RPP3 stabilized emulsions with higher stability in pHs close to neutral, whereas the opposite was found for RPP6.5, which stabilized more stable emulsions in acidic conditions. Rapeseed proteins recovered from cold-pressed RPC could be a suitable natural emulsifier and precipitation pH can be used to monitor the stability in emulsions with different pHs.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

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