scholarly journals Effect of Sodium Caseinates Addition on the Rheological Properties of Kefir during Gel Formation

2016 ◽  
Vol 5 (1) ◽  
pp. 114
Author(s):  
Kleio D. Antoniou ◽  
Stylianos Exarhopoulos ◽  
Stylianos N. Raphaelides ◽  
Georgia Dimitreli ◽  
Apostolos S. Thomareis
Keyword(s):  
Elastic Modulus ◽  
Loss Tangent ◽  
Protein Interactions ◽  
Ph Value ◽  
Bovine Milk ◽  
Three Dimensional ◽  
Fermented Milk ◽  
Elastic Behavior ◽  
Gel Formation ◽  
Fermentation Time

The effect of Sodium Caseinates (SCN) addition on the rheological behavior of kefir during gel formation was monitored by means of a dynamic rheometer of novel design (U-tube Rheometer). Kefir samples were prepared from homogenized and pasteurized full fat (3.5% w/w) bovine milk with or without the addition of SCN at varying concentrations (1%, 2% or 3% w/w). A fermented milk inoculum derived from kefir grains was inoculated into the heat-treated milk and incubated at 25°C until the pH dropped to 4.6. According to the results, the fermentation time required for the onset of gelation, as well as for the pH value to reach 4.6 increased with increasing SCN concentration. The beginning of cross-linking of proteins towards aggregates that leads to the formation of a three-dimensional protein matrix, took place at higher pH values with increasing SCN concentration. The values of elastic modulus and loss tangent that correspond to this point decreased with increasing SCN content. The increase in SCN concentration caused the values of elastic modulus during gel formation to increase and those of loss tangent to decrease. The addition of caseins into the milk increased the number and the strength of the protein-protein interactions causing the elastic behavior of the samples to increase. The presence of SCN into the system of kefir greatly affected the formation of the kefir gel.

scholarly journals The influence of the introduction of rice bran on fermented milk drink

2021 ◽  
Vol 23 (96) ◽  
pp. 39-45
Author(s):  
M. Samilyk ◽  
X. Qin ◽  
Y. Luo
Keyword(s):  
Rice Bran ◽  
Apparent Viscosity ◽  
Ph Value ◽  
Storage Period ◽  
Titratable Acidity ◽  
Fermented Milk ◽  
Biological Properties ◽  
Industrial Wastes ◽  
Raw Material ◽  
Fermentation Time

Rice bran is an agro-industrial waste with excellent nutritional value and a considerable content of bioactive compounds. Biotransformation processes by fermented milk drink fermentation increase the interest in obtaining products from agro-industrial wastes with good biological properties. The viability of introducing rice bran (RB) into fermented milk drinks to improve the structural stability and sensory was studied. Fermented milk drink supplemented with 0, 0.1 %, 0.3 %, 0.5 %, 0.7 % amount of RB were studied. Samples were stored for 28 days at 4 ± 1 °C. Samples composition was studied, Physicochemical properties (total titratable acidity, apparent viscosity, and pH) and consumer’s acceptability of fermented milk drinks were determined at 0, 7th, 14th, 21th and 28th days of storage. Studies showed that rice bran wan rich in dietary fiber (28.57 %), fat (21.56 %), and protein (11.18 %). The introduction of RB showed a significant influence on these parameters (P < 0.05). The introduction of RB would significantly improve the value of titratable acidity and apparent viscosity and decrease pH value. The more rice bran was added, the higher the values of titratable acidity and apparent viscosity were. The lower the pH value was, which could shorten the fermentation time, improve the texture stability, save production cost. The storage period could significantly influence the value of titratable acidity, pH, and apparent viscosity. The longer the storage period was, the higher the titratable acidity values were, the lower the pH value was caused by the post-fermentation of fermented milk drink. The apparent viscosity showed a trend of rising first and falling then during the storage period. The introduction of RB could significantly influence the sensory characteristic (color, consistency, sour, and texture). The introduction of RB would lead to whey separation and rough structure. Fermented milk drink supplemented with 0.1 % RB showed higher sensory acceptance. The best shelf life of the sample is 14 days，during which time fermented milk drink was of the best quality. RB is a kind of raw material with bright application prospects in a fermented milk drink.

Printability assessment of psyllium husk (isabgol)/gelatin blends using rheological and mechanical properties

2020 ◽  
pp. 088532822097947
Author(s):  
Piyush Sunil Agarwal ◽  
Suruchi Poddar ◽  
Neelima Varshney ◽  
Ajay Kumar Sahi ◽  
Kiran Yellappa Vajanthri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Storage Modulus ◽  
Loss Tangent ◽  
Loss Modulus ◽  
Three Dimensional ◽  
Elastic Behavior ◽  
Flow Index ◽  
Plastic Behavior ◽  
Psyllium Husk

The primary goal of this study is to highlight the rheological and mechanical properties of a new blend composed of naturally-derived hydrogel materials- psyllium husk (PH) and gelatin (G) for its potential use in three-dimensional (3D) printing technology. The mixtures were prepared at various weight ratios of 100PH, 75PH + 25G and 50PH + 50G. A suitable selection of the printable ink was made based on the preliminary screening steps of manual filament drop test and layer stacking by 3D printing. Printing of the common features such as hexagon and square grids helped evaluating shape fidelity of the chosen ink. Although 50PH + 50G blend was found meeting most of the criteria for an ideal 3D printable ink, rheological and mechanical characterizations have been performed for all the ratios of polymeric blends. This study documents the correlation between various factors of rheology that should be taken into account while categorizing any biomaterial as a printable ink. Yield stress was measured as 18.59 ± 4.21 Pa, 268.74 ± 13.56 Pa and 109.16 ± 9.85 Pa for 50PH + 50G, 75PH + 25G and 100PH, respectively. Similarly, consistency index (K) and flow index (n) were calculated using the power law equation and found as 49.303 ± 4.17, 530.59 ± 10.92, 291.82 ± 10.53 and 0.275 ± 0.04, 0.05 ± 0.005, 0.284 ± 0.04 for 50PH + 50G, 75PH + 25G and 100PH, respectively. The loss modulus (G″) was observed dominating over storage modulus (G′) for 50PH + 50G, that depicts its liquid-like property; whereas storage modulus (G′) was found dominating in case of 75PH + 25G and 100PH, indicating their solid-like characteristics. In addition, the loss tangent value (tan δ) of 50PH + 50G was observed exceeding unity (1.05), supporting its plastic behavior, unlike 75PH + 25G (0.5) and 100PH (0.33) whose loss tangent values were estimated less than unity revealing their elastic behavior. Also, 50PH + 50G was found to have the highest mechanical strength amongst the three blends with a Young’s modulus of 9.170 ± 0.0881 kPa.

Three Dimentional Finite Element Modeling of Microstructural Development of Nacre in Seashells and Implication on Mineralization of CaCO3

1999 ◽  
Vol 599 ◽  
Author(s):  
D. R. Katti ◽  
K. S. Katti
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Organic Phase ◽  
Elastic Moduli ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Multilayered Structure ◽  
Elastic Behavior ◽  
Microstructural Development ◽  
Organic Layer

AbstractThree dimensional finite element models of nacre were constructed based on reported microstructural studies on the ‘brick and mortar’ micro-architecture of nacre. 3D eight noded isoparametric brick elements were used to design the microarchitecture of nacre. Tensile tests were simulated using this model at stresses of 2 MPa which occur well within the elastic regime of nacre and thus effects related to locus and extent of damage were ignored. The reported values of elastic moduli of organic (0.005 GPa) and aragonitic platelets (205 GPa) were used in our simulations and the resulting displacements were found to be extremely large and corresponding to a very low modulus of 0.011 GPa. The reported elastic modulus of nacre is of the order of 50 GPa. The large displacements can possibly result from two possibilities. Firstly. the organic layer due to its multilayered structure is possibly composed of distinct layers of different elastic moduli. A significantly higher modulus of the organic phase may be possible near the organic-inorganic interface. Simulations using variable elastic moduli for the organic phase suggest that an elastic modulus of 15 GPa is consistent with the observed elastic behavior of nacre. A second possibility for the observed higher elastic modulus may arise from localized platelet-platelet contact. Since the observed modulus of nacre lies within the above two extremes (i.e. 15 GPa and 205 GPa) it is suggested that a combination of the two, i.e. a higher modulus of the organic phase near the organic-inorganic interface and localized platelet-platelet contact can result in the observed elastic properties of nacre.

scholarly journals Effect of Oat β-Glucan on the Rheological Characteristics and Microstructure of Set-Type Yogurt

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4752
Author(s):  
Xiaoqing Qu ◽  
Yuliya Nazarenko ◽  
Wei Yang ◽  
Yuanyang Nie ◽  
Yongsheng Zhang ◽  
...  
Keyword(s):  
Sensory Evaluation ◽  
Network Structure ◽  
Theoretical Basis ◽  
Fermentation Process ◽  
Three Dimensional ◽  
Rheological Characteristics ◽  
Fermentation Time ◽  
Spherical Aggregate ◽  
Dimensional Network ◽  
Solid Liquid

The oat β-glucan (OG) was added into set-type yogurt as a functional ingredient, in order to evaluate effects on the rheological characteristics and microstructure of set-type yogurt. When the OG concentration increased from 0 to 0.3%, the WHC gradually increased. At 0.3% OG, the set-type yogurt had the highest WHC of 94.67%. Additionally, the WHC continuously decreased, reaching the lowest WHC (about 80%) at 0.5% OG. When 0.3% OG was added, the highest score of sensory evaluation was about 85. The rheological result showed that the fermentation process went through the changes as follows: solid → liquid → solid → liquid. The addition of 0.3% OG decreased the fermentation time of set-type yogurt by about 16 min, making yogurt more inclined to be liquid. The acidity of set-type yogurt with OG was slightly higher. The result of microstructure showed that the addition of OG destroyed the three-dimensional network structure of yogurt, and some spherical aggregate particles could be clearly observed at 0.3% OG. Overall, this study provided a theoretical basis for the application of OG in set-type yogurt.

scholarly journals Three-dimensional thermomechanical converting of CTMP substrates: effect of bio-based strengthening agents and new mineral filling concept

Cellulose ◽  
2021 ◽  
Vol 28 (15) ◽  
pp. 9751-9768
Author(s):  
Teija Laukala ◽  
Sami-Seppo Ovaska ◽  
Ninja Kerttula ◽  
Kaj Backfolk
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Three Dimensional ◽  
Microfibrillated Cellulose ◽  
New Mineral ◽  
Thermomechanical Pulp ◽  
Cationic Starch ◽  
Precipitated Calcium Carbonate ◽  
Filling Method ◽  
Positive Effect

AbstractThe effects of bio-based strengthening agents and mineral filling procedure on the 3D elongation of chemi-thermomechanical pulp (CTMP) handsheets with and without mineral (PCC) filling have been investigated. The 3D elongation was measured using a press-forming machine equipped with a special converting tool. The strength of the handsheets was altered using either cationic starch or microfibrillated cellulose. Precipitated calcium carbonate (PCC) was added to the furnish either as a slurry or by precipitation of nano-sized PCC onto and into the CTMP fibre. The 3D elongation of unfilled sheets was increased by the dry-strengthening agents, but no evidence on the theorised positive effect of mineral fill on 3D elongation was seen in either filling method. The performance of the strengthening agent depended on whether the PCC was as slurry or as a precipitated PCC-CTMP. The starch was more effective with PCC-CTMP than when the PCC was added directly as a slurry to the furnish, whereas the opposite was observed with microfibrillated cellulose. The 3D elongation correlated positively with the tensile strength, bursting strength, tensile stiffness, elastic modulus and bending stiffness, even when the sheet composition was varied, but neither the strengthening agent nor the method of PCC addition affected the 3D elongation beyond what was expectable based on the tensile strength of the sheets. Finally, mechanisms affecting the properties that correlated with the 3D elongation are discussed.

scholarly journals Structural Characterization of Receptor–Receptor Interactions in the Allosteric Modulation of G Protein-Coupled Receptor (GPCR) Dimers

2021 ◽  
Vol 22 (6) ◽  
pp. 3241
Author(s):  
Raudah Lazim ◽  
Donghyuk Suh ◽  
Jai Woo Lee ◽  
Thi Ngoc Lan Vu ◽  
Sanghee Yoon ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Metabotropic Glutamate Receptor ◽  
Three Dimensional ◽  
Allosteric Modulation ◽  
Experimental Investigations ◽  
G Protein Coupled Receptor ◽  
Metabotropic Glutamate ◽  
Gpcr Activation ◽  
G Protein Coupled

G protein-coupled receptor (GPCR) oligomerization, while contentious, continues to attract the attention of researchers. Numerous experimental investigations have validated the presence of GPCR dimers, and the relevance of dimerization in the effectuation of physiological functions intensifies the attractiveness of this concept as a potential therapeutic target. GPCRs, as a single entity, have been the main source of scrutiny for drug design objectives for multiple diseases such as cancer, inflammation, cardiac, and respiratory diseases. The existence of dimers broadens the research scope of GPCR functions, revealing new signaling pathways that can be targeted for disease pathogenesis that have not previously been reported when GPCRs were only viewed in their monomeric form. This review will highlight several aspects of GPCR dimerization, which include a summary of the structural elucidation of the allosteric modulation of class C GPCR activation offered through recent solutions to the three-dimensional, full-length structures of metabotropic glutamate receptor and γ-aminobutyric acid B receptor as well as the role of dimerization in the modification of GPCR function and allostery. With the growing influence of computational methods in the study of GPCRs, we will also be reviewing recent computational tools that have been utilized to map protein–protein interactions (PPI).

Limit Load Analysis of Cracked Components Using the Reference Volume Method

2006 ◽  
Vol 129 (3) ◽  
pp. 391-399 ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Elastic Modulus ◽  
Three Dimensional ◽  
Local Limit ◽  
Limit Load ◽  
Multiple Cracks ◽  
Element Analysis ◽  
Limit Loads ◽  
Integrity Assessment ◽  
Reference Volume ◽  
Volume Method

Cracks and flaws occur in mechanical components and structures, and can lead to catastrophic failures. Therefore, integrity assessment of components with defects is carried out. This paper describes the Elastic Modulus Adjustment Procedures (EMAP) employed herein to determine the limit load of components with cracks or crack-like flaw. On the basis of linear elastic Finite Element Analysis (FEA), by specifying spatial variations in the elastic modulus, numerous sets of statically admissible and kinematically admissible distributions can be generated, to obtain lower and upper bounds limit loads. Due to the expected local plastic collapse, the reference volume concept is applied to identify the kinematically active and dead zones in the component. The Reference Volume Method is shown to yield a more accurate prediction of local limit loads. The limit load values are then compared with results obtained from inelastic FEA. The procedures are applied to a practical component with crack in order to verify their effectiveness in analyzing crack geometries. The analysis is then directed to geometries containing multiple cracks and three-dimensional defect in pressurized components.

Performance Based Evaluation of Bridge Substructure in North Mississippi Using Nonlinear FEM and Field Vibration Measurement

2000 ◽  
Author(s):  
Chris L. Mullen ◽  
Prabin R. Tuladhar
Keyword(s):  
Finite Element ◽  
Transfer Functions ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Vibration Measurement ◽  
Elastic Behavior ◽  
Evaluation Procedure ◽  
Vibration Measurements ◽  
Linear Elastic ◽  
Performance Based Evaluation

Abstract Discussion of a Performance - Based Engineering evaluation procedure for an existing interstate highway bridge in north Mississippi. The bridge is in a highly trafficked location near the Memphis Metropolitan area and is reflective of modern design practices in Mississippi. Results are presented of nonlinear damage response and displacement ductility performance of the reinforced concrete bents and their foundations predicted using static finite element (FE) computations. The model considers the composite action of the concrete and the reinforcing steel materials under axial force, shear, torsion and flexure. The performance-based evaluation includes three-dimensional computational simulations of the nonlinear bridge system, including substructures and superstructure. The response spectrum dynamic analysis method will also be carried out on the linear elastic three-dimensional model to predict the linear elastic behavior. Field vibration measurements, including ambient and hammer-impact, were performed to calibrate the models. The computed transfer functions are currently being evaluated to correlate vibration measurements and the Finite element models.

scholarly journals Changes in folate characteristics and its identification in broccoli (Brassica oleracea Italica) extract fermented by Lactic Acid Bacteria Mixed Culture (LAB)

2018 ◽  
Vol 154 ◽  
pp. 04001 ◽  
Author(s):  
Yati Maryati ◽  
Agustine Susilowati
Keyword(s):  
Lactic Acid ◽  
Folic Acid ◽  
Lactic Acid Bacteria ◽  
Brassica Oleracea ◽  
Acid Concentration ◽  
Ph Value ◽  
Starter Culture ◽  
Time Interval ◽  
Fermentation Time ◽  
Total Sugars

Broccoli (Brassica oleracea Italica) was fermented by cultures of lactic acid bacteria (LAB) as a potential source of natural folic acid. This study aimed to evalte characteristic changes and to identify folate compounds from broccoli extract, fermented by mixed LAB cultures (L. bulgaricus, S. thermophulus, L.acidophilus, Bd. bifidum). The formulation of broccoli extract was fermented with variation of LAB starter culture with concentrations of 10 and 20%(v/v), and the change of characteristic of folic acid compound during fermentation (0 to 48 hours) with an interval of 8 hours was evaluated. The results showed that the fermentation of broccoli extract with different concentration of LAB culture had an effect on the concentration of folic acid produced, as well as the change of concentration of folic acid during the fermentation time interval. The optimum condition was obtained based on the highest folic acid concentration of 6.74%, at culture concentration of 20% during 24 hour fermentation with the value of folic acid concentration of 72.11 μg/mL, pH value of 4.29, total sugars of 34.61%, total acids of 0, 97%, dissolved protein of 14.64 mg/mL and total LAB of log 13.02 + 0.05 cfu / ml.

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