Apparent Viscosity Measurements Research Articles

Gradually modified fibers of Yucca Filifera (Asparagaceae) as biodegradable and mechanical reinforcement of polypropylene composites

AbstractThe preparation and characterization of Yucca Filifera (Asparagaceae) fibers (YFF) and their incorporation into polypropylene (PP) matrices of two molecular weights are reported. Apart from the fibers sectioning and dehydration, saponates, phenols, hemicellulose, and lignin were systematically extracted. Moisture was a primary factor in the as‐sectioned samples, and dehydration was followed by volatiles extraction, including saponates and phenols. An optimized mixture of alcohols (80% methanol/20% ethanol v/v) was used to extract the remaining volatiles (adsorbed water, phenols, and saponates). The dried fibers were then cyclically treated in an autoclave using a dilute sodium hydroxide (NaOH) with the purpose of decreasing external lignin and hemicellulose. After extractions, the fiber product was directly incorporated into PP of two molecular weights, film/fiber (PP35) and injection molding (PP11) grades. The average crystallization temperatures from the melt increased slightly in the presence of YFF as an indication of heterogeneous nucleation. Although the crystallization degree decreased perceptibly depending on the fiber content. The apparent viscosity measurements as a function of shear rate, at low fiber concentrations (10 wt%), displayed partial compatibility between the treated YFF and PP11. In contrast, high fiber concentrations (30 wt%) in PP35 showed only a range of partial compatibility at high shear rates. Mechanical elongation and bending demonstrated an increase in the corresponding moduli as an indication of fiber reinforcement with a biodegradable additive. The higher tensile modulus was obtained at the expense of mechanical deformation.Highlights A desert plant fiber works as reinforcement for PP composites. The fibers preparation extracts saponates, phenols, and partially lignin and hemicellulose. Fibers are heterogeneous enough for compatibility with the PP matrices. Fibers mechanically reinforced PP in proportion to their concentration. Reinforcement depends on the molecular weight of the PP matrix.

Antioxidative Properties of Fermented Soymilk Using Lactiplantibacillus plantarum LP95.

In recent times, there has been a growing consumer interest in replacing animal foods with alternative plant-based products. Starting from this assumption, for its functional properties, soymilk fermented with lactic acid bacteria is gaining an important position in the food industry. In the present study, soymilk was fermented with Lactiplantibacillus plantarum LP95 at 37 °C, without the use of stabilizers as well as thickeners and acidity regulators. We evaluated the antioxidant capacity of fermented soymilk along with its enrichment in aglycone isoflavones. The conversion of isoflavone glucosides to aglycones (genistein, glycitein, and daidzein) was analyzed together with antioxidant activity (ABTS) measurements, lipid peroxidation measurements obtained by a thiobarbituric acid reactive substance (TBARS) assay, and apparent viscosity measurements. From these investigations, soymilk fermentation using Lp. plantarum LP95 as a starter significantly increased isoflavones' transformation to their aglycone forms. The content of daidzein, glycitein, and genistein increased after 24 h of fermentation, reaching levels of 48.45 ± 1.30, 5.10 ± 0.16, and 56.35 ± 1.02 μmol/100 g of dry weight, respectively. Furthermore, the antioxidant activity increased after 6 h with a reduction in MDA (malondialdehyde). The apparent viscosity was found to increase after 24 h of fermentation, while it slightly decreased, starting from 21 days of storage. Based on this evidence, Lp. plantarum LP95 appears to be a promising candidate as a starter for fermented soymilk production.

Experimental and modeling studies on dynamic barite sag and effects of particle size, shear rate, and fluid rheology

Barite is often utilized to control the weight of drilling muds. However, in inclined wellbores, barite particles settle out of the mud in a lateral direction and quickly reach the wellbore wall. Over time, deposited particles form unstable barite beds that slide intermittently downward, causing downhole pressure fluctuations. The observation is often referred to as barite sag, which occurs prominently when the system is in a dynamic state. Barite sag leads to density variation in the mud system, resulting in drilling issues such as stuck pipe, fluid loss and lost circulation, loss of well control, and wellbore instability. Various experimental studies have been conducted on barite sag, but limited mathematical modeling has been undertaken.This article presents the results of experimental and mathematical modeling studies on barite sag. First, particle size distribution tests were performed with API barite. Then, different oil-based muds (OBMs) were prepared using barite samples with various particle size distributions. Next, the apparent viscosities of the muds were measured with a rheometer. Then, the Viscometer Sag Shoe Test (VSST) method was used to study barite sag at 49 °C varying rotational speed and barite particle size distribution. Furthermore, the settling behavior of barite particles under dynamic conditions was simulated using a sedimentation-consolidation model. The model is solved numerically by applying a fully implicit finite difference method. The accuracy of the numerical solution is validated using simulation results presented in a previous study. The model has been improved to handle non-Newtonian fluids and simulate dynamic conditions.According to the apparent viscosity measurements, barite particle size has a minor effect on OBM rheology. The VSST results also show that barite sag increases with particle size and rotational speed. The improved model predicts VSST results fairly well. Additionally, a model-based parametric study indicates that barite sag decreases with increasing OBM rheological parameters (consistency index, yield stress, and fluid behavior index).

Effect of Pickering Emulsion Stabilized by Soy Protein Nanoparticles on Physical and Rheological Properties of Gluten-Free Cake Batter

In this research, Pickering emulsion (PE) stabilized by soy protein nanoparticles (SPNs) and xanthan gum, was added to gluten-free cake batter based on rice flour. The physical and rheological properties of the PE-containing batter were quantified, compared with the control sample. The results revealed that the addition of the PE to the batter decreased its specific gravity, which in turn increased the volume and reduced the hardness of the cake. The power-law model with a high determination coefficient ( R 2 ) could best describe the flow behavior of the batter. Measurement of apparent viscosity, consistency coefficient, and flow behavior index indicated that the gluten-free cake batter had shear-thinning behavior. Moreover, the oscillatory test results showed that the PE-containing batter had more liquid-like behavior than the PE-free sample.

Effects of different gases on the performance of foams stabilized by Cocamidopropyl betaine surfactant and silica nanoparticles: A comparative experimental study

Application of CO 2 gas in foam enhanced oil recovery (EOR) processes has emerged as a win-win strategy for achieving higher oil recovery factor and reducing greenhouse gas emission, which can significantly help the protection of the ozone layer from depletion. However, lower stability of CO 2 -foam, as compared to the N 2 - and CH 4 -foams, has tempted us to examine combinations of CO 2 with these gases to not only improve the stability of the produced foam but also have CO 2 as the gaseous phase of the foam. In this study, we investigated the effect of different gases and the mixture thereof on the performance of foams in EOR while the aqueous phase of foams is a constant mixture of Cocamidopropyl betaine surfactant (0.03 wt %) and silica nanoparticle (0.1 wt%). To this end, seven different gases, including N 2 , CO 2 , CH 4 , 80% N 2 + 20% CO 2 , 80% CH 4 + 20% CO 2 , 50% CH 4 + 50% CO 2 , 50% N 2 + 50% CO 2 were used as the gases phase for foam generation, and the performance of the produced foams were examined through the following experiments: bulk foam stability tests, apparent foam viscosity measurements, and core flooding tests. The results of foam stability tests showed that half-life time for the CO 2 -, CH 4 -, and N 2 -foams are 13.5, 17.0, and 44.0 min, respectively. Also, as revealed from apparent viscosity measurements, the N 2 - and 80% N 2 +20% CO 2 foams have higher apparent foam viscosity values followed by 50% N 2 +50% CO 2 foam. Furthermore, we showed that a combination of 80% N 2 + 20% CO 2 as the gaseous phase for foam generation could not only improve CO 2 -foam stability, as compared to other foams, but also can substantially increase ultimate oil recovery (56.6 %OOIP), even more than that for N 2 foam (48.6 %OOIP), obtained from core flooding experiments.

Magneto‐hydrodynamic mixing: A new technique for preparing carbomer hydrogels

AbstractMagnetohydrodynamic mixing was evaluated as an alternative to conventional high shear mixing (HSM) in the preparation of carbomer hydrogels containing 1.22 wt% Carbopol® 980 NF. Neutralization of the carbomer dispersion (pH = 2.74) with triethanolamine (TEA) enabled to adjust the pH of the mixture and tune the viscosity of the hydrogel. Using HSM, this approach was limited to 0.2 wt% TEA (pH = 3.83) as the gel became too viscous and the recirculation flow dropped from 12 to 0.3 m3/h. Magnetohydrodynamic mixing enabled to reach TEA concentrations up to 1.0 wt% (pH = 5.31). Apparent viscosity measurements on samples having 0.2 wt% TEA revealed lower viscosities for carbomer hydrogels prepared with HSM, that is, 6800 mPa s versus 8800 mPa for magneto‐hydrodynamic mixing. Based on 1H NMR evidence, this decrease in apparent viscosity was attributed to structural damage to the carbomer backbone in combination with mechanochemical degradation of the added TEA.

The Pressure and Temperature Dependency of Relative Volume, Low Shear Viscosity, and Non-Newtonian High Shear Viscosity in SAE AS5780 HPC, MIL-PRF-23699 HTS, and DOD-PRF-85734 Lubricants

This work quantifies the high-pressure rheological performance of two jet engine turbine oils and three helicopter transmission oils. The jet engine oils are qualified for both the MIL-PRF-23699 high thermal stability and AS5780 high performance classifications, and the helicopter oils are classified against DOD-PRF-85734. Rheological properties include relative volume, low shear, and high shear viscosity. Relative volume measurements are presented for temperatures ranging from 20 to 100 °C and up to 300 MPa. Low shear viscosity measurements range from 20 to 100 °C and up to 1 GPa. Apparent shear or high shear viscosity measurements varied pressure up to 550 MPa and shear stresses up to 5 MPa. The non-Newtonian limit for each lubricant was observed. Rheological models obtained from the measurements include the Tait and Murnaghan relative volume models, the Williams-Landel-Ferry (WLF) modified Yasutomi low shear viscosity model, and both the modified Carreau-Yasuda and double modified Carreau-Yasuda shear viscosity models. The regressed models highlight shortcomings of classical elastohydrodynamic lubrication (EHL) expressions in describing the measured lubricants’ rheological response. These property models support the development of modern EHL calculations as they relate to high-performance aerospace applications.

Proteomic Analysis of Silk Fibroin Reveals Diverse Biological Function of Different Degumming Processing From Different Origin.

Silk, as a kind of natural fibrin, has been prepared into various biomaterials due to its excellent biocompatibility and mechanicalness. However, there are some controversies on the biocompatibility of silk fibroin (SF), especially when it coexists with sericin. In this study, two kinds of silk from Jiangsu and Zhejiang were degummed with two concentrations of Na2CO3 solution, respectively, to obtain four kinds of silk fibroin. The effects of different degumming treatments on silk fibroin properties were analyzed by means of color reaction, apparent viscosity measurement, and transmission electron microscope and isobaric tags for relative and absolute quantification analyses, and the effects of different silk fibroin membranes on the growth of Schwann cells were evaluated. The results showed that the natural silk from Zhejiang treated with 0.05% Na2CO3 solution had a fuller structure, higher apparent viscosity, and better protein composition. While SF obtained by degumming with 0.5% Na2CO3 solution was more beneficial to cell adhesion and proliferation due to the thorough removal of sericin. This study may provide important theoretical and experimental bases for the selection of biomaterials for fabricating artificial nerve grafts.

Numerical Simulation of the Influence of Taylor Vortex on the Apparent Viscosity Measurement of Semi-Solid Metallic Based On ANSYS Fluent

The apparent viscosity of semi-solid metallic slurry with a low solid fraction, which is one of the most essential parameters for representing the rheological behavior, is mainly measured by the concentric cylinder rotational approach. The principle of this method is based on the assumptions that the fluid is in an ideal laminar flow state and obey the Newton’s internal friction law. However, as the angular velocity ω increases, the fluid undergoes a transition from a stable laminar flow state to a Taylor vortex and turbulent flow state. These unstable flow conditions such as Taylor vortex and turbulence have a severe impact on the accuracy of apparent viscosity measurement. However, these unstable flow conditions are difficult to monitored and analyzed in real time through experimental methods. Computer numerical simulation technology provides the possibility and convenience for the visualization of the flow state of the semi-solid metallic slurry in the measurement system. In this work, ANSYS Fluent was used to simulate the apparent viscosity measurement process of semi-solid slurry, and the flow state transition process of the semi-solid slurry in the measurement system was successfully visualized and analyzed. In order to avoid the influence of Taylor vortex, combined with the measurement principle of the concentric cylinder rotational rheometer and Taylor’s study on flow stability, the empirical equation of limiting speed to avoid Taylor vortex in the process of Searle rheometer viscosity measurement is given.

Apparent Viscosity Measurement of Solid-liquid Coexisting Fluid by Falling Ball Method for Evaluation Iron Particle Sedimentation Velocity in Slag

Apparent Viscosity Measurement of Solid-liquid Coexisting Fluid by Falling Ball Method for Evaluation Iron Particle Sedimentation Velocity in Slag

A novel promising delivery system for cuminaldehyde using gelled lipid nanoparticles: Characterization and anticancer, antioxidant, and antibacterial activities

This work aimed to develop a novel nanoencapsulation system for food colloidal formulations using gelled lipid nanoparticles (GLNs) to improve the functionality, stability, and bioactivity of cuminaldehyde as a highly volatile and poor hydrophilic food additive. Cuminaldehyde-loaded GLNs with diameters of 117–138 nm were fabricated through a hot emulsification process with monoglyceride (10 and 15 g/100 g lipid phase) as a lipid gelator at two concentrations of cuminaldehyde (500 and 1000 mg/L). All samples remained stable towards macroscopic phase separation and creaming during 28 days of storage at 4 °C, which could be related to the rigid structure of dispersed particles in the gelled state and retarding droplet movement. Moreover, all samples were stable to creaming after subjecting to the environmental changes including temperature (30, 60, and 90 °C for 30 min), ionic strength (100, 200, and 300 mM NaCl), and pH (3, 5, and 7). Measurement of apparent viscosity showed non-Newtonian shear thinning nature in all samples, which was more pronounced at higher concentrations of the gelator. Interestingly, higher cytotoxic effects of cuminaldehyde against human lung and colorectal cancer cells were observed after encapsulation within GLNs. However, weak toxicity was also found against normal peripheral blood mononuclearcells.On the other hand, the antioxidant activity and lipid oxidation stability were improved by increasing cuminaldehyde concentration, while it was reduced at higher monoglyceride concentration. All samples exhibited stronger antibacterial activity against Bacillus cereus than Eschershia coli. These findings suggest the significant potential benefits of GLNs as novel nanocarriers to enrich various food and beverage formulations with essential oils, flavors, and aromas.

Measurement of Apparent Powder Viscosity by Tuning-fork Vibration Viscometer

Measurement of Apparent Powder Viscosity by Tuning-fork Vibration Viscometer

Synthesis of a novel amphoteric copolymer and its application as a dispersant for coal water slurry preparation.

In this work, a novel amphoteric copolymer named Poly(sodium p-styrenesulfonate–co-acrylic acid-co-diallyldimethylammonium chloride) (P(SS-co-AA-co-DMDAAC)) was synthesized via free radical polymerization. Afterwards, P(SS-co-AA-co-DMDAAC) was explored for use as a dispersant in coal water slurry (CWS) preparation. The structure of P(SS-co-AA-co-DMDAAC) was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The synthetic conditions were optimized as the feed ratio of AA to SS was 1 : 1 (for Yulin coal) or 1.5 : 1 (for Yili coal), and DMDAAC dosage was 4.0 wt% (for Yulin coal) and 6.0 wt% (for Yili coal) toward total monomers. The performances of P(SS-co-AA-co-DMDAAC) as a dispersant for CWS were evaluated by various technologies, such as apparent viscosity, zeta potential, static stability and contact angle measurements. The results revealed that the optimized dosage of P(SS-co-AA-co-DMDAAC) in CWS preparation was 0.3 and 0.4 wt% for Yulin coal and Yili coal respectively. In this optimum condition, CWS prepared using P(SS-co-AA-co-DMDAAC) as dispersant showed a typical shear thinning behaviour and excellent stability, which are desired in industries. The rheological models also confirmed the pseudo-plastic characteristics of CWS. Finally, compared with the widely used anionic dispersant naphthalene sulphonate formaldehyde condensate (NSF) and poly(sodium p-styrenesulfonate) (PSS), P(SS-co-AA-co-DMDAAC) developed in this work exhibited better slurry making performance. The introduction of cationic functional groups promoted the adsorption of the dispersant, which further enhanced the electrostatic repulsion and steric hindrance among coal particles. Accordingly, the viscosity of CWS decreased and static stability enhanced.

Rheology and tribology of starch + κ-carrageenan mixtures.

In this study, we investigated the rheological and tribological properties of biopolymer mixtures of gelatinized corn starches (0.5 – 10.0 wt%) and κ‐carrageenan (κC) (0.05 – 1.0 wt%). Two different starch samples were used. The first starch (CS1), despite extensive heating and shearing contained “ghost” granules, while the second starch (CS2) had no visible ghost granules after the same gelatinization process as CS1. Apparent viscosity measurements demonstrated that κC + CS1 mixtures were shear thinning liquids, with viscosity values being lower than the corresponding weight average of the values of the individual equilibrium phases at shear rates < 50 s−1. Tribological results revealed that κC ≥ 0.5 wt% was required to observe any decrease in friction coefficients in the mixed lubrication regime. Starch (CS1) showed an unusual behavior at ≥ 5 wt%, where the friction coefficient decreased not only in the mixed regime but also in the boundary regime, probably due to the presence of the “ghost” granules, as the latter became entrained in the contact region. The CS1 + κC mixtures showed significantly lower friction coefficients than that of pure CS1 and κC in the mixed regime. However, the CS2 + κC mixture (i.e., containing no ghost granules) showed similar behavior to pure κC in the mixed regime, while lower friction coefficients than that of the pure CS2 and κC in the boundary regime. These findings illustrate new opportunities for designing biopolymer mixtures with tunable lubrication performance, via optimizing the concentrations of the individual biopolymers and the gelatinization state of the starch.

3D-printable supramolecular hydrogels with shear-thinning property: fabricating strength tunable bioink via dual crosslinking

3-dimensional (3D) bioprinting technology provides promising strategy in the fabrication of artificial tissues and organs. As the fundamental element in bioprinting process, preparation of bioink with ideal mechanical properties without sacrifice of biocompatibility is a great challenge. In this study, a supramolecular hydrogel-based bioink is prepared by polyethylene glycol (PEG) grafted chitosan, α-cyclodextrin (α-CD) and gelatin. It has a primary crosslinking structure through the aggregation of the pseudo-polyrotaxane-like side chains, which are formed from the host-guest interactions between α-CD and PEG side chain. Apparent viscosity measurement shows the shear-shinning property of this bioink, which might be due to the reversibility of the physical crosslinking. Moreover, with β-glycerophosphate at different concentrations as the secondary crosslinking agent, the printed constructs demonstrate different Young's modulus (p < 0.001). They could also maintain the Young's modulus in cell culture condition for at least 21 days (p < 0.05). By co-culturing each component with fibroblasts, CCK-8 assay demonstrate cellular viability is higher than 80%. After bioprinting and culturing, immunofluorescence staining with quantification indicate the expression of Ki-67, Paxillin, and N-cadherin is higher in day 14 than those in day 3 (p < 0.05). Oil red O and Nissl body specific staining reflect strength tunable bioink may have impact on the cell fate of mesenchymal stem cells (p < 0.05). This work might provide new idea for advanced bioink in the application of re-establishing complicated tissues and organs.

Rheological and sensorial evaluation of yogurt incorporated with red propolis.

The aim of the present study was to evaluate the use of red propolis extract, as a natural additive, in yogurt. For this, yogurt was produced with red propolis extract (YRP), to replace the additive chemical potassium sorbate, used in the commercial yogurt (CY). Analysis for apparent viscosity, texture and sensorial acceptance were performed. Apparent viscosity and texture measurements of the samples were similar to the control. Sensory evaluation showed that the samples of YRP reached a mean score of 9 on the hedonic scale, the same score found for CY. Regarding the purchase intention, the samples of YRP showed a positive intention by 64.45% of the consumers, and for CY, 68.89%. For the taste, texture, aroma and consistency, the scores were in the range from 8 to 10, for both samples. It can be concluded that the yogurt incorporated with red propolis presents potential for its commercialization in the Brazilian market.

Pickering emulsions stabilised by hydrophobically modified cellulose nanocrystals: Responsiveness to pH and ionic strength

The aims of this study were to hydrophobically modify cellulose nanocrystals (CNCs), investigate the ability of such modified CNCs (MCNCs) to stabilise Pickering oil-in-water (O/W) emulsions and understand their stability at different pHs (2.0–7.0) and ionic strengths (0–150 mM NaCl). Structural changes that resulted from esterifying CNCs with octenyl succinic anhydride (OSA) were determined using Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), transmission electron microscopy (TEM) and wettability analysis. The stability of the Pickering O/W emulsions (20 wt% oil, 0.05–1.00 wt% MCNCs) was assessed using droplet sizing, microscopy, ζ-potential, apparent viscosity and oscillatory rheological measurements. FTIR spectroscopy confirmed a decrease in the intensity of the –OH-associated band because of reaction of the hydroxyl groups with OSA. XRD indicated a lower (11.5%) crystallinity index in MCNCs. TEM revealed that there was no change in morphology of the needle-shaped CNCs upon OSA modification (length/diameter = 40–100 nm/2–4 nm). Hydrophobic modification of CNCs with OSA was evidenced by an increase in static water contact angle from 56° (untreated CNCs) to 80.2° (MCNCs) which allowed the MCNCs to be partially wetted by both the phases and stabilise O/W emulsions. The Pickering emulsions showed droplet flocculation at pH < 4.0 (without addition of NaCl) or ionic strength ≥ 20 mM NaCl (pH 7.0), with a predominant elastic gel-like behaviour observed at ≥ 20 mM NaCl. Resistance of MCNC-based Pickering emulsions to coalescence and responsiveness to flocculation at bio-relevant pHs and ionic strengths show promise in the design of delivery vehicles.

Effects of stick–slip transition on polymer melt apparent shear viscosity measurement

ABSTRACTA twin‐bore capillary rheometer is used for the apparent shear viscosity measurement of commercial polyolefin melts based on Ostwald‐de Waele model. The effects of stick–slip transition of linear low‐density polyethylene (LLDPE) and high‐density polyethylene (HDPE) are investigated. The maximum error of apparent shear viscosity calculated by corrected shear rate is 23% when the stick–slip transition occurs. Based on the entanglement‑disentanglement theory, a schematic diagram for shear stress curve containing stick–slip transition is presented to illustrate polymer melt flow in capillary. In this study, the critical stress at the beginning of stick–slip transition at 220 °C is 23.01 kPa higher than that at 190 °C, and why it increases with increasing temperature is discussed with a molecular mechanism in combination with entropy elasticity and entanglement‑disentanglement theory. Through the analysis of ULDPE, PS, EVA, and K‐Resin, it can be found that short branches or side groups are helpful to avoid the stick–slip transition. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48230.

Porous Beads of in-situ Calcium Hexaluminate Prepared by Extrusion-Dripping

Abstract: Structures comprised of mixtures of corindon (α-Al2O3) and calcium hexaluminate (CaAl12O19 or CA6) show high refractoriness and chemical resistance. This article addresses the in situ formation of porous alumina-CA6 beads (approximately 2-3 mm) prepared by an extrusion-dripping process with sodium alginate (SA) as a coagulation agent. The best conditions for a simultaneous dispersion of aqueous mixtures of the precursor raw materials, fine alumina, and calcium carbonate (β-CaCO3 or calcite), in an SA solution were investigated by Zeta potential and apparent viscosity measurements and turbidity tests. Extrusion-dripped beads of different compositions were consolidated by the ionotropic gelation of SA in a Ca2+ solution. A net of thin coagulated-SA filaments restraining solid particles was registered by scanning electron microscopy. Different pore generation mechanisms were observed during heating up to 1500 °C. Variations in the initial Al2O3-CaCO3 ratio yielded a wide range of compositions, microstructures, and physical properties (total porosity, crystalline phase content, and pore size distribution).

Uticaj temperature i vremena čuvanja na reološke osobine odabranih kečapa od paradajza

This article is focused on monitoring and evaluation of rheological properties of tomato ketchups. The aim of the work was to show the importance of the knowledge about rheological properties of materials and determine qualitative changes in ketchup behaviour dependent on temperature changes and storage time. The measurements of all samples were carried out under the same conditions in approximate temperature range (5 - 30) °C. First measurements were performed at the beginning of storing, second measurements were done after two weeks of storing and last measurements were realised after four weeks of storing. There were constructed dependencies of rheologic properties on temperature and storage time and evaluated by the regression equations and the coefficients of determination. Ketchup is a non-Newtonian material, so apparent viscosity was measured. The measurements of apparent viscosity were performed on a digital rotational viscometer Anton Paar DV - 3P. Densities of measured samples were determined according to definition. We found out that apparent viscosity of samples decreased exponentially with increasing temperature, so the Arrhenius equation is valid. Ketchup's fluidity was increasing exponentially with the temperature. We also found out that apparent viscosity had decreased with storage time and on the other hand fluidity was increasing with storage time, which can be caused by structural changes in samples during storing. Temperature dependencies of ketchup densities were sufficiently characterized by decreasing linear function in measured temperature range. The calculated rheological characteristics can be used for designing of technological equipment or containers for distribution of the product to the final users. The knowledge of flow behaviour is also important for the development of new recipes and direct qualitative assessment of the products.