Displaying publications 61 - 80 of 241 in total

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  1. Seow EK, Gan CY, Tan TC, Lee LK, Easa AM
    J Food Sci Technol, 2019 Apr;56(4):2105-2114.
    PMID: 30996444 DOI: 10.1007/s13197-019-03691-z
    Present study compared the rheological properties of glutinous rice flour (GRF) gel (33.3%, w/v) added with raw bee honey (RBH) or stingless bee honey (SBH) with/without heating treatment. RBH (diatase activity: 12.14 Schade) and SBH (1.53 Schade) significantly reduced the network of GRF gel by lowering the gel viscosity, with RBH having the highest rate of viscosity decrease (- 2.74 × 10-5 Pa). As the addition of heated-SBH or heated-RBH did not reduce gel viscosity, it was hypothesised that active diastase played a major role to weaken gel network. This was further supported by the significant and the lowest storage modulus (G') value of RBH-GRF gel (5.99 ± 0.02 Pa), as compared to SBH-GRF (6.27 ± 0.04 Pa) and control (6.33 ± 0.04 Pa). A detail of rheological behaviour of the gels was further explained using power law. Overall, this GRF gel model has successfully demonstrated the potential of honey diastase in weakening network of starch-based food.
    Matched MeSH terms: Viscosity
  2. Nirmal U
    Polymers (Basel), 2018 Sep 25;10(10).
    PMID: 30960991 DOI: 10.3390/polym10101066
    The current work is an attempt to reduce friction coefficient of the treated betelnut fibre reinforced polyester (T-BFRP) composites by aging them in twelve different solutions with different kinematic viscosities. The test will be performed on a pin on disc (POD) wear test rig using different applied loads (5⁻30 N), different sliding distances (0⁻6.72 km) at sliding speed of 2.8 m/s subjected to a smooth stainless steel counterface (AISI-304). Different orientations of the fibre mats such as anti-parallel (AP) and parallel (P) orientations subjected to the rotating counterface will be considered. The worn surfaces were examined through optical microscopy imaging and it was found that the aged specimens had significantly lower damages as compared to neat polyester (NP) and the unaged samples. Besides, P-O samples revealed lower friction coefficients as compared to AP-O, i.e., reduction was about 24.71%. Interestingly, aging solutions with lower kinematic viscosities revealed lower friction coefficients of the aged T-BFRP composites when compared to the ones aged in higher kinematic viscosities.
    Matched MeSH terms: Viscosity
  3. Idrus NFM, Zzaman W, Yang TA, Easa AM, Sharifudin MS, Noorakmar BW, et al.
    Food Sci Biotechnol, 2017;26(4):911-920.
    PMID: 30263619 DOI: 10.1007/s10068-017-0132-0
    Peanut (Arachis hypogaea) is an important source of protein and lipid globally. The effect of superheated-steam roasting on quality of peanut oil was evaluated based on physicochemical quality parameters. Three roasting temperatures (150, 200, and 250 °C) were used for different periods of roasting time and the obtained results were compared with those of conventional roasting. At 250 °C, superheated-steam roasted peanuts yielded more oil (26.84%) than conventionally roasted peanuts (24.85%). Compared with conventional roasting, superheated-steam roasting resulted in lower oil color, peroxide, p-anisidine, free fatty acid, conjugated diene and triene, and acid values and higher viscosity and iodine values in the roasted peanut oil. These values were significantly different from each other (p 
    Matched MeSH terms: Viscosity
  4. Krishnan S, Abd Ghani N, Aminuddin NF, Quraishi KS, Razafindramangarafara BL, Baup S, et al.
    Ultrason Sonochem, 2021 Jun;74:105576.
    PMID: 33975186 DOI: 10.1016/j.ultsonch.2021.105576
    This study investigates the potential of using small amounts of ionic liquids (IL) to enhance ultrasound-assisted extraction of lipids content from green microalgae. Three imidazolium-based ILs (butyl, octyl and dodecyl), each of them with two anions (bromide and acetate) were tested as additives. Viscosity and surface tension of the ILs aqueous mixtures were analyzed to determine the influence of ILs' anions and alkyl chain length, whereas KI dosimetry experiments were used as an indicator of radicals formation. A key finding suggests that the small addition of ILs improves the ultrasonication either by enhancing the viscosity and reducing the water surface tension, leading to a more powerful acoustic cavitation process or by increasing HO° production likely to oxidize the microalgae cells membranes, and consequently disrupting them on a more efficient manner. KI dosimetry also revealed that long ILs alkyl chain is detrimental. This experimental observation is confirmed thus strengthened as the yield of extracted lipids from green microalgae has shown an incremental trend when the IL concentration also increased. These hypotheses are currently under investigation to spot detailed impact of ILs on cavitation process.
    Matched MeSH terms: Viscosity
  5. Yap AU, Ong JE, Yahya NA
    J Mech Behav Biomed Mater, 2021 01;113:104120.
    PMID: 33086137 DOI: 10.1016/j.jmbbm.2020.104120
    OBJECTIVES: This study determined the effects of self-adhesive resin coatings on viscoelastic properties of highly viscous glass ionomer cements (HVGICs) using dynamic mechanical analysis.

    MATERIALS AND METHODS: The HVGICs evaluated were Zirconomer [ZR] (Shofu), Equia Forte [EQ] (GC) and Riva [RV] (SDI). Sixty specimens (12mm x 2mm x 2mm) of each material were fabricated using customized Teflon molds. After initial set, the specimens were removed from their molds, finished, measured and randomly divided into 3 groups of 20. Half the specimens in each group were left uncoated while the remaining half was covered with the respective manufacturers' resin coating. The specimens were subsequently conditioned in distilled water, artificial saliva or citric acid at 37°C for 7 days. The uncoated and coated specimens (n=10) were then subjected to dynamic mechanical testing in flexure mode at 37°C with a frequency of 0.1 to 10Hz. Storage modulus, loss modulus and loss tangent data were subjected to normality testing and statistical analysis using one-way ANOVA/Scheffe's post-hoc test and Ttest at significance level p<0.05.

    RESULTS: Mean storage modulus ranged from 1.39 ± 0.36 to 10.80 ± 0.86 GPa while mean loss modulus varied from 0.13 ± 0.03 to 0.70 ± 0.14 GPa after conditioning in the different mediums. Values for loss tangent ranged from 39.4 ± 7.75 to 213.2 ± 20.11 (x10 -3 ). Significant differences in visco-elastic properties were observed between mediums and materials. When conditioned in distilled water and artificial saliva,storage modulus was significantly improved when ZR, EQ and RV were uncoated. Significantly higher values were, however, observed with resin coating when the materials were exposed to citric acid.

    CONCLUSION: The visco-elastic properties of HVGICs were influenced by both resin coating and chemical environment.

    Matched MeSH terms: Viscosity
  6. Ruzaina, I., Norizzah, A.R., Halimahton Zahrah, M.S., Cheow, C.S., Adi, M.S., Noorakmar, A.W., et al.
    MyJurnal
    Guava is a climacteric fruit which has high nutritional content. It is a highly perishable fruit, undergoes rapid postharvest ripening in a few days under ambient condition. This paper aims to determine the effect of palm stearin and palm kernel olein blends on maintaining the quality of guava during storage. Two different coating formulations of palm stearin (PS) and palm kernel olein (PKOo) blends (1:1 and 3:2) were analysed for their slip melting point (SMP), cohesiveness, viscosity and density. Beeswax was used as a commercial coating for comparison whiles the uncoated guava was used as control. These coatings were applied onto guavas by hand-wipe technique using a sponge. Guavas were dried in corrugated fibre board boxes and stored in an air-conditioned room maintained at 20°C while a chiller maintained at 10°C was used for chilled temperature. Coating pick up, thickness and surface area were measured while guava properties were analysed for coating effect on weight loss, O2 and CO2 gases, firmness and glossiness during storage at ambient temperature (20°C) for 21 days and chilled temperature (10ºC) for 30 days. Microstructure analysis was conducted within 2 days of coating at ambient temperature (20ºC). The results obtained indicated that 1:1 PSPKOo blends had higher cohesiveness compared to beeswax. Both PSPKOo blends significantly (p
    Matched MeSH terms: Viscosity
  7. Syafiq, A., Amir, I.Z., Sharon, W.X.R.
    MyJurnal
    The impacts on both rheological parameters; Casson yield stress and Casson viscosity were determined. The interactions among blend’s components; xanthan gum (XG), corn starch (CS), glycerin (GL) and their relationship with both flow parameters were also investigated by using D-Optimal mixture design. Three levels of cocoa butter substitution assigned in chocolate production were at 5%, 10% and 15% level with random proportions of each component generated by Design Expert software. An appropriate mathematical model was applied to evaluate each response as a function of the proportions of the components enabling in prediction of future response by using any blend of components. As the incorporation of the blends (XG/CS/GL) in chocolate production was elevated from 5% to 15%, both parameters; viscosity and yield stress of chocolate were gradually increased, as in range 7.819 to 10.529 Pa, and 2.372 to 3.727 Pa.s, respectively. Neither binary nor ternary component-component interaction exhibited synergistic effect. Nevertheless, strongest antagonistic effect on both rheological parameters of substituted chocolate at 5% level and 10% level were respectively observed at ternary interaction region for the former, and at binary interaction area of CS:GL, closer to CS corner as for the latter. This study somehow provides ideas on how component-component interactions influence experimented response.
    Matched MeSH terms: Viscosity
  8. Gopinath, V.K., Arzreanne , A.R.
    MyJurnal
    The objective of this study was to evaluate the effects of salivary testing in dental caries assessment. The role of saliva flow rate, pH, viscosity and buffering capacity in subjects with high caries (DMFT>5) (group 1) against subjects with low caries (DMFT=0) (control group) were evaluated. 40 subjects between the age of 18 and 40 years old were selected (20 subjects control group and 20 subjects group 1). By using a salivary testing kit (GC Asia Dental Pte Ltd, Japan), each subject underwent test such as hydration status of the oral mucosa, viscosity and pH of resting saliva, stimulated salivary flow rate and buffering capacity of stimulated saliva. The results showed that the flow rate, viscosity, pH and buffering capacity of saliva in subjects of group 1 (DMFT>5) was significantly lower (p
    Matched MeSH terms: Viscosity
  9. Ahmad, Z., Rohana, H., Md Tahir, P.
    ASM Science Journal, 2013;7(1):37-58.
    MyJurnal
    This study investigated the thermal properties of three room temperature curing adhesives containing nano particles which were thixotropic and shear thinning which allowed injection into overhead holes when exposed to different environmental conditions. Viscosity and shear stress of the adhesives were measured as a function of shear rate. The thermal behaviour of the adhesives were measured using dynamic mechanical thermal anylisis following exposures to different temperatures and humidities which included temperatures of 20 degrees Celcius, 30 degrees Celcius and 50 degrees Celcius, relative humidities of 65% RH, 75% RH 95% RH soaked in water at 20 degrees Celcius and placed in the oven at 50 degrees Celcius. The dynamic thermal properties reported include storage and loss modulus, the loss tangent and the glass transition temperature ( Tg ). For nano- and micro-particles filled adhesives, the Tg increased with the temperature increase, even though the adhesives was subjected to high humidity and this was due to further cross-linking. The results showed that room temperature cured epoxies were only partially cured at room temperature.
    Matched MeSH terms: Viscosity
  10. Zzaman, W., Issara, U., Febrianto, N.F., Yang, T.A.
    International Food Research Journal, 2014;21(3):10191-1023.
    MyJurnal
    The study was conducted to investigate fatty acid composition, rheological properties and crystal formation of rambutan fat and cocoa butter. The results showed that lauric acid, palmitic acid, and stearic fatty acid in rambutan fat were less than cocoa butter, but oleic acid found almost the same. The crystal formation of cocoa butter was not complex at 25oC, while rambutan fat and their mixture shown complicated network of crystal form. The Newton, Bingham and Casson plastic rheological models was used to describe fat flow in this experiment and the result showed that rambutan fat had higher viscosity than cocoa fat. Based on the results the study recommended that mixture proportion up to 30% rambutan seed fat can be used as a cocoa butter substitute whereas higher proportion completely alters original cocoa butter properties. Therefore, there is feasibility of using the rambutan fat to substitute cocoa butter and the mixtures of the two fats in suitable proportion in chocolate manufacturing.
    Matched MeSH terms: Viscosity
  11. Akanbi, T.O., Nazamid, S., Adebowale, A.A.
    MyJurnal
    This study was carried out to determine the proximate, functional and pasting properties of breadfruit starch. Breadfruit starch was isolated from matured breadfruit (Artocarpus altilis) and was analyzed for its fuctional, proximate and pasting properties. The starch contains 10.83%, 0.53%, 0.39%, 22.52%, 77.48% and 1.77% moisture, crude protein, fat, amylose, amylopectin and ash contents respectively. The average particle size, pH, bulk density and dispersibility of the breadfruit starch were 18 μm, 6.5, 0.673 g/mls, and 40.67% respectively. The swelling power of the breadfruit starch increases with increase in temperature, but there was a rapid increase in the swelling power from 70 to 80 0C. The pasting temperature of the starch paste was 84.05 0C, setback and breakdown values were 40.08 and 7.92 RVU respectively. The peak viscosity value was 121.25 RVU while final viscosity value was 153.42 RVU. This study concluded that breadfruit starch has an array of functional, pasting and proximate properties that can facilitate its use in so many areas where the properties of other starches are acceptable.
    Matched MeSH terms: Viscosity
  12. Suseno, S.H., Tajul, A.Y
    MyJurnal
    This study was aimed at improving the quality of fish oil. A synthetic filter aid (Magnesol XL) was used at various concentration (1, 3 and 5%) and time levels (5, 10, 15 and 20 minutes) to adsorb the polar compound products of the oil. Some physical and chemical properties (viscosity, colour, density, acid value, peroxide value and free fatty acid) of the treated oil were determined. Results indicate that Magnesol XL at 1 and 3% levels significantly reduced the acid value, peroxide value and free fatty acid contents of the treated oil.
    Treatment of the fish oil with Magnesol XL at 1 and 3% levels was also better than treatment with 5% Magnesol XL on improving the fish oil quality. The fatty acid profile for Σ n3 at untreated and treatment adsorbent showed significant at 0.05 level but not significant at Magnesol XL adsorbent concentration 1-5%.
    Matched MeSH terms: Viscosity
  13. Sanaei, A.V., Mahmoodani, F., See, S.F., Yusop, S.M., Babji, A.S.
    MyJurnal
    The extraction of catfish (Clarias gariepinus) bone gelatin was optimized by using Response Surface Methodology (RSM) involving 4-factors, 5-levels Central Composite Design (CCD). The optimum conditions for extraction were produced by a pre-treatment of 3.35% HCl for 14.5 h along with hot water extraction at 67.23°C for 5.2 h. Results showed that the predicted yield by RSM (61.81%) was closely matched the experimental yield of 60.54%. The results also indicated that the extracted bone gelatin possessed high protein content (81.75%) and imino acid (proline and hydroxyproline) (144 residues per 1000 residues), with gel strength (230.25 g), viscosity (4.64 mPa.s) and isoionic point (5.35) comparable to that of bovine gelatin. The results suggested that RSM is a great optimizing tool for extraction of gelatin from clarias catfish bone and values of the physicochemical properties of gelatin are higher or comparable than those from other fish species and bovine gelatin.
    Matched MeSH terms: Viscosity
  14. Nurul, A.G., Sarbon, N.M.
    MyJurnal
    This study examines and compares the influence of pH on the functional, rheological and structural properties of eel skin (Monopterus sp.) and bovine gelatins. Functional properties studied and compared were emulsifying capacity and stability; water holding capacity; fat binding capacity; foaming capacity; and foaming stability. The rheological properties studied include gel strength and dynamic oscillatory measurements. The structural properties of eel skin and bovine gelatin were determined by Fourier transform infrared spectroscopy (FTIR). Results obtained showed that eel skin gelatin treated at pH 8 (compared to pH 5) exhibited the higher emulsifying, fat binding, foaming and viscoelasticity properties. The FTIR spectrum assay showed that eel skin gelatin presented a similar structure to that of bovine gelatin. This study demonstrated that pH levels influence functional, rheological and structural properties of eel skin gelatin and that these properties were enhanced to either equal or surpass those of bovine gelatin. Hence, this study indicates that eel skin gelatin has immense potential for use as an alternative to bovine gelatin.
    Matched MeSH terms: Viscosity
  15. Wong CW, Tan HH
    J Food Sci Technol, 2017 Feb;54(2):564-571.
    PMID: 28242955 DOI: 10.1007/s13197-017-2501-3
    This paper presents the enzymatic liquefaction process for honey jackfruit optimized with Pectinex® Ultra SP-L and Celluclast® 1.5 L individually or in combinations at different concentrations (0-2.5% v/w) and incubation time (0-2.5 h). Treatment with combinations of enzymes showed a greater effect in the reduction of viscosity (83.9-98.8%) as compared to single enzyme treatment (64.8-87.3%). The best parameter for enzymatic liquefaction was obtained with 1.0% (v/w) Pectinex® Ultra SP-L and 0.5% (v/w) Celluclast® 1.5 L for 1.5 h. Spray drying process was carried out using different inlet temperatures (140-180 °C) and maltodextrin concentrations (10-30% w/w). Results indicated that the spray-dried honey jackfruit powder produced at 160 °C with 30% w/w maltodextrin gave the highest product yield (66.90%) with good powder qualities in terms of water activity, solubility, moisture content, hygroscopicity, color and bulk density. The spray-dried honey jackfruit powder could potentially be incorporated into various food products.
    Matched MeSH terms: Viscosity
  16. Siti Rashima R, Maizura M, Kang WM, Fazilah A, Tan LX
    J Food Sci Technol, 2017 Jan;54(1):228-235.
    PMID: 28242920 DOI: 10.1007/s13197-016-2454-y
    The effects of sodium chloride (NaCl) (3.5%) solution and polysaccharides, such as carboxymethyl cellulose (CMC) (0.1, 0.3 and 0.5%) and gum arabic (5, 10 and 15%), on the physicochemical properties, antioxidant capacity and sensory characteristics of bitter gourd juice were investigated. An increase in the concentration of CMC and gum arabic significantly was observed to increase the lightness (L value) and the viscosity (mPas) of bitter gourd juice at all levels. Increased concentrations of gum arabic significantly increased the total soluble solids. The bitter gourd fruit treated with NaCl solution produced the highest lightness (L value) and scavenging activity of free radical 2,2-diphenyl-1-picrylhydrazyl of bitter gourd juice. Increased concentration of gum arabic up to 15% significantly increased the total phenolic content. The addition of 5% gum arabic effectively reduced the bitterness of the bitter gourd juice. Viscosity of the juice resulted in negative correlation for bitterness.
    Matched MeSH terms: Viscosity
  17. Nura, M., Kharidah, M., Jamilah, B., Roselina, K.
    MyJurnal
    This study examined the physicochemical properties of rice flours with five different particle sizes (≤63, 80, 100, 125, and 140 μm) prepared by dry milling and their effects on textural properties of laksa noodles. Rice flour with the smallest particle size had the highest water absorption index, peak viscosity, hot paste viscosity, breakdown, final or cold paste viscosity and gel hardness, but the lowest gelatinization temperature. Reduction of rice flour particle size improved textural properties of laksa noodle. Laksa noodle produced from rice flour with the smallest particle size had the best textural properties.
    Matched MeSH terms: Viscosity
  18. Mohd Sofian Alias, Nik Ghazali Nik Salleh, Khairiah Badri, Mohd Hamzah Harun, Mahathir Mohamad, Mohd Yusof Hamzah, et al.
    MyJurnal
    UV curable coating formulation comprises urethane acrylate resin and nanosilica as filler were synthesized to develop UV curable inorganic organic hybrid composite (PUA). The surface of the nanosilica was chemically modified to improve its chemical interaction within the urethane acrylate matrix. The modification had been undertaken by applying vinyltrymetoxysilane (VTMOS) that acted as a coupling agent to produce organophilic silica shell (SIMA). The shell is linked to the silica via reaction with the surface silanol group of the silica. The disappearance of metoxy groups in VTMOS was demonstrated by FTIR spectrum. The percentage of silica particles in UV curable hybrid formulation were varied on 5%, 10%, 15%, 20% and 250% respectively. In this work, the formulation was applied on medium density fiber board (11/IDF) substrate and subsequent has been irradiated under UV light. Then, the coated MDF were characterized by several testing equipments (TGA, DSC, scratch tester, instron, SEM). From the result, we found that the addition of silica nanoparticles exhibit significant improvement in coating film properties as compared to film without silica nanoparticle includes significant improvement in its modulus and scratch resistance. This make them as promising coating candidate for MDF product. On the other hand, we also found that an increase of silica particle up to 25 wt%, the viscosity has increased rapidly indicates that it is not suitable for acrylate coating formulation due to disappearance of desired effect known as tixotrophy.
    Matched MeSH terms: Viscosity
  19. Mohd. Hilmi Mahmood, Shahrol Najmin Baharom, Rida Tajau, Mek Zah Salleh, Khairul Zaman Mohd. Dahlan, Rosley Che Ismail
    MyJurnal
    Various palm oil (RBD Palm Olein) based urethane acrylate prepolymers (UPs) having different structures and molecular weights were synthesised from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following established synthesis procedures described elsewhere. The products (UPs) were compared with each other in terms of their molecular weights (MW), viscosities and UV curing performances of pressure sensitive adhesives (PSA) UP based formulations. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers tend to determine the molecular weights and hence viscosities of the final products of urethane acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the coatings and adhesive properties of UV curable UP based PSA.
    Matched MeSH terms: Viscosity
  20. Durairaj, R., Leong, K.C., Chia Wea, L., Wong, M.C.
    ASM Science Journal, 2011;5(2):109-114.
    MyJurnal
    Lead-free solder paste printing processes account for the majority of assembly defects in the electronic manufacturing industry. In the stencil printing process, the solder paste must be able to withstand low and high shear rates which result in continuous structural breakdown and build-up. This study investigated the effect of the addition of nickel and platinum powders to the thixotropic behaviour of lead-free Sn/Ag/Cu solder pastes using the structural kinetic model. A hysteresis loop test and constant shear test were utilized to investigate the thixotropic behaviour of the pastes using parallel plate rheometry at 25ºC. In this study, the shear rates were increased from 0.01 s–1 to 10 s–1 and the second curve was a result of decreasing the shear rate from 10 s–1 to 0.01 s–1. For the constant shear test, the samples were subjected to five different shear rates of 0.01s–1, 0.1s–1, 1s–1, 10s–1 and 100s–1. The constant shear rate test was designed to study the structural breakdown and build-up of the paste materials. From this investigation, the hysteresis loop test was shown to be an effective test method to differentiate the extent of structural recovery in the solder pastes. All the pastes showed a high degree of shear thinning behaviour with time. This might be due to the agglomeration of particles in the flux that prohibited paste flow under low shear rate. The action of high shear rate would break the agglomerates into smaller pieces which facilitated the flow of pastes, thus viscosity was reduced at high shear rate.
    Matched MeSH terms: Viscosity
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