Displaying publications 361 - 380 of 10373 in total

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  1. Fulltext Preparation of astaxanthin nanodispersions using gelatin-based stabilizer systems
    Anarjan N, Nehdi IA, Sbihi HM, Al-Resayes SI, Malmiri HJ, Tan CP
    Molecules, 2014 Sep 10;19(9):14257-65.
    PMID: 25211006 DOI: 10.3390/molecules190914257
    The incorporation of lipophilic nutrients, such as astaxanthin (a fat soluble carotenoid) in nanodispersion systems can either increase the water solubility, stability and bioavailability or widen their applications in aqueous food and pharmaceutical formulations. In this research, gelatin and its combinations with sucrose oleate as a small molecular emulsifier, sodium caseinate (SC) as a protein and gum Arabic as a polysaccharide were used as stabilizer systems in the formation of astaxanthin nanodispersions via an emulsification-evaporation process. The results indicated that the addition of SC to gelatin in the stabilizer system could increase the chemical stability of astaxanthin nanodispersions significantly, while using a mixture of gelatin and sucrose oleate as a stabilizer led to production of nanodispersions with the smallest particle size (121.4±8.6 nm). It was also shown that a combination of gelatin and gum Arabic could produce optimal astaxanthin nanodispersions in terms of physical stability (minimum polydispersity index (PDI) and maximum zeta-potential). This study demonstrated that the mixture of surface active compounds showed higher emulsifying and stabilizing functionality compared to using them individually in the preparation of astaxanthin nanodispersions.
    Matched MeSH terms: Excipients/chemistry*; Gelatin/chemistry*; Xanthophylls/chemistry
  2. Fulltext Effect of nitric acid concentrations on synthesis and stability of maghemite nanoparticles suspension
    Nurdin I, Johan MR, Yaacob II, Ang BC
    ScientificWorldJournal, 2014;2014:589479.
    PMID: 24963510 DOI: 10.1155/2014/589479
    Maghemite (γ-Fe2O3) nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), alternating gradient magnetometry (AGM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension.
    Matched MeSH terms: Ferric Compounds/chemistry*; Nitric Acid/chemistry*; Nanoparticles/chemistry*
  3. Fulltext Ultrasound-assisted extraction of antioxidants in Misai Kucing (Orthosiphon stamineus)
    Ho SK, Tan CP, Thoo YY, Abas F, Ho CW
    Molecules, 2014 Aug 19;19(8):12640-59.
    PMID: 25153876 DOI: 10.3390/molecules190812640
    Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and extraction time (min). Antioxidant compounds were determined by total phenolic content and total flavonoid content to be 1.4 g gallic acid equivalent/100 g DW and 45 g catechin equivalent/100 g DW, respectively. Antioxidant activities were evaluated using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical scavenging capacity assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging capacity assay to be 1,961.3 and 2,423.3 µmol Trolox Equivalent Antioxidant Capacity (TEAC)/100 g DW, respectively. Based on the optimal conditions, experimental values were reported to be close to the predicted value by RSM modeling (p>0.05), indicating the suitability of UAE for extracting the antioxidants of Misai Kucing. Rosmarinic acid, kaempferol-rutinoside and sinesetine were identified by high performance liquid chromatography-mass spectrometry.
    Matched MeSH terms: Biphenyl Compounds/chemistry; Free Radicals/chemistry; Picrates/chemistry; Plant Extracts/chemistry; Sulfonic Acids/chemistry; Free Radical Scavengers/chemistry; Orthosiphon/chemistry*; Benzothiazoles/chemistry
  4. Purification and characterisation of a novel amylase enzyme from red pitaya (Hylocereus polyrhizus) peel
    Amid M, Abd Manap MY
    Food Chem, 2014 Dec 15;165:412-8.
    PMID: 25038694 DOI: 10.1016/j.foodchem.2014.03.133
    An amylase enzyme from pitaya peel was purified 234.2-folds with 72.1% recovery using ammonium sulphate precipitation, gel filtration and ion exchange chromatography. Gel filtration chromatography and SDS-PAGE revealed that the enzyme is monomeric with a molecular weight of 42.1kDa. The apparent Km and Vmax of the amylase were 2.7 mg/ml and 34.30 u/min/mg of protein, respectively. The enzyme was highly active and stable over a wide pH range from pH 3 to pH 11.0, with optimum activity being observed at pH 5.0. The enzyme was highly selective for soluble starch, amylopectin, glycogen and pulullan. The purified amylase did not require calcium and displayed extreme stability with regard to surfactants and oxidising agents. EDTA, a powerful chelating agent, did not have any significant effect on the stability of the enzyme. Such characteristics have not been previously reported for this type of enzyme from fruit peel. This enzyme, which possesses unique properties, could be widely used in different types of industries, especially in food and biotechnological applications.
    Matched MeSH terms: Amylases/chemistry*; Fruit/chemistry*; Cactaceae/chemistry*
  5. Nutritional compositions and bioactivities of Dacryodes species: a review
    Tee LH, Yang B, Nagendra KP, Ramanan RN, Sun J, Chan ES, et al.
    Food Chem, 2014 Dec 15;165:247-55.
    PMID: 25038673 DOI: 10.1016/j.foodchem.2014.05.084
    Dacryodes species are evergreen, perennial trees with fleshy fruits and belong to the family Buseraseae. Many Dacryodes species are underutilized but are widely applied in traditional folk medicine to treat malaria, fever and skin diseases. The nutritional compositions, phytochemicals and biological activities of Dacryodes edulis, Dacryodes rostrata, Dacryodes buettneri, Dacryodes klaineana and Dacryodes hexandra are presented. The edible fruits of D. edulis are rich in lipids, proteins, vitamins, fatty acids and amino acids. Its extracts (leaf, fruit and resin) exhibit antioxidant, anti-microbial, anti-carcinogenic and other bioactivities. D. rostrata fruit has significant nutrient content, and is rich in proteins, lipids and minerals. These fruits are also highly rich in polyphenols, anthocyanins and antioxidant activities. This comprehensive review will assist the reader in understanding the nutritional benefits of Dacryodes species and in identifying current research needs.
    Matched MeSH terms: Antioxidants/chemistry*; Fruit/chemistry; Plant Extracts/chemistry*
  6. Fulltext Hematite nanoparticles-modified electrode based electrochemical sensing platform for dopamine
    Kamali KZ, Alagarsamy P, Huang NM, Ong BH, Lim HN
    ScientificWorldJournal, 2014;2014:396135.
    PMID: 25136664 DOI: 10.1155/2014/396135
    Hematite (α-Fe2O3) nanoparticles were synthesized by the solid transformation of ferrous hydroxide and ferrihydrite in hydrothermal condition. The as-prepared α-Fe2O3 nanoparticles were characterized by UV-vis, PL, XRD, Raman, TEM, AFM, FESEM, and EDX analysis. The experimental results indicated the formation of uniform hematite nanoparticles with an average size of 45 nm and perfect crystallinity. The electrochemical behavior of a GC/α-Fe2O3 electrode was studied using CV and EIS techniques with an electrochemical probe, [Fe(CN)6](3-/4-) redox couple. The electrocatalytic activity was investigated toward DA oxidation in a phosphate buffer solution (pH 6.8) by varying different experimental parameters. The chronoamperometric study showed a linear response in the range of 0-2 μM with LoD of 1.6 μM for DA. Square wave voltammetry showed a linear response in the range of 0-35 μM with LoD of 236 nM for DA.
    Matched MeSH terms: Dopamine/chemistry*; Electrochemistry/methods; Ferric Compounds/chemistry*; Nanoparticles/chemistry*
  7. Flexural properties of poly(methyl methacrylate) resin reinforced with oil palm empty fruit bunch fibers: a preliminary finding
    John J, Ann Mani S, Palaniswamy K, Ramanathan A, Razak AA
    J Prosthodont, 2015 Apr;24(3):233-8.
    PMID: 24976147 DOI: 10.1111/jopr.12191
    PURPOSE: The purpose of this preliminary study was to evaluate the flexural properties of poly(methyl methacrylate) (PMMA) reinforced with oil palm empty fruit bunch (OPEFB) fiber.

    MATERIALS AND METHODS: The flexural strength and flexural modulus of three OPEFB fiber-reinforced PMMA were compared with a conventional and a commercially available reinforced PMMA. The three test groups included OPEFB fibers of 0.5 mm thickness, 2.0 mm thickness, and OPEFB cellulose.

    RESULTS: All test group specimens demonstrated improved flexural strength and flexural modulus over conventional PMMA. Reinforcement with OPEFB cellulose showed the highest mean flexural strength and flexural modulus, which were statistically significant when compared to the conventional and commercially reinforced PMMA used in this study. OPEFB fiber in the form of cellulose and 0.5 mm thickness fiber significantly improved flexural strength and flexural modulus of conventional PMMA resin. Further investigation on the properties of PMMA reinforced with OPEFB cellulose is warranted.

    CONCLUSIONS: Natural OPEFB fibers, especially OPEFB in cellulose form, can be considered a viable alternative to existing commercially available synthetic fiber reinforced PMMA resin.

    Matched MeSH terms: Cellulose/chemistry*; Dental Materials/chemistry; Polymethyl Methacrylate/chemistry*
  8. Antioxidant and α-glucosidase inhibitory activities of 40 tropical juices from Malaysia and identification of phenolics from the bioactive fruit juices of Barringtonia racemosa and Phyllanthus acidus
    Sulaiman SF, Ooi KL
    J Agric Food Chem, 2014 Oct 1;62(39):9576-85.
    PMID: 25198055 DOI: 10.1021/jf502912t
    The present study compared pH, total soluble solids, vitamin C, and total phenolic contents, antioxidant activities, and α-glucosidase inhibitory activities of 40 fresh juices. The juice of Baccaurea polyneura showed the highest yield (74.17 ± 1.44%) and total soluble solids (32.83 ± 0.27 °Brix). The highest and lowest pH values were respectively measured from the juices of Dimocarpus longan (6.87 ± 0.01) and Averrhoa bilimbi (1.67 ± 0.67). The juice of Psidium guajava gave the highest total phenolic (857.24 ± 12.65 μg GAE/g sample) and vitamin C contents (590.31 ± 7.44 μg AAE/g sample). The juice of Phyllanthus acidus with moderate contents of total phenolics and vitamin C was found to exhibit the greatest scavenging (613.71 ± 2.59 μg VCEAC/g sample), reducing (2784.89 ± 3.93 μg TEAC/g sample), and α-glucosidase inhibitory activities (95.37 ± 0.15%). The juice of Barringtonia racemosa was ranked second in the activities and total phenolic content. Gallic and ellagic acids, which were quantified as the major phenolics of the respective juices, are suggested to be the main contributors to the antioxidant activities. The α-glucosidase inhibitory activity of the juices could be derived from myricetin and quercetin (that were previously reported as potent α-glucosidase inhibitors) in the hydrolyzed juice extracts. The juice of Syzygium samarangense, which was found to be highest in metal chelating activity (82.28 ± 0.10%), also was found to have these phenolics.
    Matched MeSH terms: alpha-Glucosidases/chemistry; Antioxidants/chemistry*; Fruit/chemistry; Plant Extracts/chemistry*; Phenol/chemistry*; Phyllanthus/chemistry*; Barringtonia/chemistry*; Glycoside Hydrolase Inhibitors/chemistry*
  9. Production of biodiesel fuel from canola oil with dimethyl carbonate using an active sodium methoxide catalyst prepared by crystallization
    Kai T, Mak GL, Wada S, Nakazato T, Takanashi H, Uemura Y
    Bioresour Technol, 2014 Jul;163:360-3.
    PMID: 24813567 DOI: 10.1016/j.biortech.2014.04.030
    In this study, a novel method for the production of biodiesel under mild conditions using fine particles of sodium methoxide formed in dimethyl carbonate (DMC) is proposed. Biodiesel is generally produced from vegetable oils by the transesterification of triglycerides with methanol. However, this reaction produces glycerol as a byproduct, and raw materials are not effectively utilized. Transesterification with DMC has recently been studied because glycerol is not formed in the process. Although solid-state sodium methoxide has been reported to be inactive for this reaction, the catalytic activity dramatically increased with the preparation of fine catalyst powders by crystallization. The transesterification of canola oil with DMC was studied using this catalyst for the preparation of biodiesel. A conversion greater than 96% was obtained at 65°C for 2h with a 3:1M ratio of DMC and oil and 2.0 wt% catalyst.
    Matched MeSH terms: Methanol/chemistry*; Fatty Acids, Monounsaturated/chemistry*; Formates/chemistry*
  10. Bionanocomposites of regenerated cellulose/zeolite prepared using environmentally benign ionic liquid solvent
    Soheilmoghaddam M, Wahit MU, Tuck Whye W, Ibrahim Akos N, Heidar Pour R, Ali Yussuf A
    Carbohydr Polym, 2014 Jun 15;106:326-34.
    PMID: 24721086 DOI: 10.1016/j.carbpol.2014.02.085
    Bionanocomposite films based on regenerated cellulose (RC) and incorporated with zeolite at different concentrations were fabricated by dissolving cellulose in 1-ethyl-3-methylimidazolium chloride (EMIMCl) ionic liquid using a simple green method. The interactions between the zeolite and the cellulose matrix were confirmed by Fourier transform infrared spectra. Mechanical properties of the nanocomposite films significantly improved as compared with the pure regenerated cellulose film, without the loss of extensibility. Zeolite incorporation enhanced the thermal stability and char yield of the nanocomposites. The scanning electron microscopy and transmission electron microscopy showed that zeolite was uniformly dispersed in the regenerated cellulose matrix. In vitro cytotoxicity test demonstrated that both RC and RC/zeolite nanocomposite films are cytocompatible. These results indicate that the prepared nanocomposites have potential applications in biodegradable packaging, membranes and biomedical areas.
    Matched MeSH terms: Biocompatible Materials/chemistry; Cellulose/chemistry*; Imidazoles/chemistry*; Solvents/chemistry; Zeolites/chemistry*; Ionic Liquids/chemistry*; Nanocomposites/chemistry*; Green Chemistry Technology
  11. Microwave-enhanced CO2 gasification of oil palm shell char
    Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M
    Bioresour Technol, 2014 Apr;158:193-200.
    PMID: 24607454 DOI: 10.1016/j.biortech.2014.02.015
    CO2 gasification of oil palm shell (OPS) char to produce CO through the Boudouard reaction (C + CO2 ↔ 2CO) was investigated under microwave irradiation. A microwave heating system was developed to carry out the CO2 gasification in a packed bed of OPS char. The influence of char particle size, temperature and gas flow rate on CO2 conversion and CO evolution was considered. It was attempted to improve the reactivity of OPS char in gasification reaction through incorporation of Fe catalyst into the char skeleton. Very promising results were achieved in our experiments, where a CO2 conversion of 99% could be maintained during 60 min microwave-induced gasification of iron-catalyzed char. When similar gasification experiments were performed in conventional electric furnace, the superior performance of microwave over thermal driven reaction was elucidated. The activation energies of 36.0, 74.2 and 247.2 kJ/mol were obtained for catalytic and non-catalytic microwave and thermal heating, respectively.
    Matched MeSH terms: Carbon Dioxide/chemistry*; Gases/chemistry*; Plant Oils/chemistry*
  12. Fulltext Identification of the hydrogeochemical processes in groundwater using classic integrated geochemical methods and geostatistical techniques, in Amol-Babol Plain, Iran
    Sheikhy Narany T, Ramli MF, Aris AZ, Sulaiman WN, Juahir H, Fakharian K
    ScientificWorldJournal, 2014;2014:419058.
    PMID: 24523640 DOI: 10.1155/2014/419058
    Hydrogeochemical investigations had been carried out at the Amol-Babol Plain in the north of Iran. Geochemical processes and factors controlling the groundwater chemistry are identified based on the combination of classic geochemical methods with geographic information system (GIS) and geostatistical techniques. The results of the ionic ratios and Gibbs plots show that water rock interaction mechanisms, followed by cation exchange, and dissolution of carbonate and silicate minerals have influenced the groundwater chemistry in the study area. The hydrogeochemical characteristics of groundwater show a shift from low mineralized Ca-HCO3, Ca-Na-HCO3, and Ca-Cl water types to high mineralized Na-Cl water type. Three classes, namely, C1, C2, and C3, have been classified using cluster analysis. The spatial distribution maps of Na(+)/Cl(-), Mg(2+)/Ca(2+), and Cl(-)/HCO3 (-) ratios and electrical conductivity values indicate that the carbonate and weathering of silicate minerals played a significant role in the groundwater chemistry on the southern and western sides of the plain. However, salinization process had increased due to the influence of the evaporation-precipitation process towards the north-eastern side of the study area.
    Matched MeSH terms: Ions/chemistry; Minerals/chemistry; Groundwater/chemistry*
  13. Fulltext Effects of using silica fume and polycarboxylate-type superplasticizer on physical properties of cementitious grout mixtures for semiflexible pavement surfacing
    Koting S, Karim MR, Mahmud H, Mashaan NS, Ibrahim MR, Katman H, et al.
    ScientificWorldJournal, 2014;2014:596364.
    PMID: 24526911 DOI: 10.1155/2014/596364
    Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of 5% silica fume with an adequate amount of superplasticizer and water/cement ratio was beneficial in improving the properties of the cementitious grout.
    Matched MeSH terms: Plasticizers/chemistry*; Polycarboxylate Cement/chemistry*; Silicon Dioxide/chemistry*
  14. Primary recovery of a bacteriocin-like inhibitory substance derived from Pediococcus acidilactici Kp10 by an aqueous two-phase system
    Abbasiliasi S, Tan JS, Ibrahim TA, Kadkhodaei S, Ng HS, Vakhshiteh F, et al.
    Food Chem, 2014 May 15;151:93-100.
    PMID: 24423507 DOI: 10.1016/j.foodchem.2013.11.019
    A polymer-salt aqueous two-phase system (ATPS) consisting of polyethylene-glycol (PEG) with sodium citrate was developed for direct recovery of a bacteriocin-like inhibitory substance (BLIS) from a culture of Pediococcus acidilactici Kp10. The influences of phase composition, tie-line length (TLL), volume ratio (VR), crude sample loading, pH and sodium chloride (NaCl) on the partition behaviour of BLIS was investigated. Under optimum conditions of ATPS, the purification of BLIS was achieved at 26.5% PEG (8000)/11% sodium citrate with a TLL of 46.38% (w/w), VR of 1.8, and 1.8% crude load at pH 7 without the presence of NaCl. BLIS from P. acidilactici Kp10 was successfully purified by the ATPS up to 8.43-fold with a yield of 81.18%. Given that the operation of ATPS is simple, environmentally friendly and cost-effective, as it requires only salts and PEG, it may have potential for industrial applications in the recovery of BLIS from fermentation broth.
    Matched MeSH terms: Pediococcus/chemistry*; Polyethylene Glycols/chemistry; Sodium Chloride/chemistry
  15. Fulltext Dynamic modeling of reversible methanolysis of Jatropha curcas oil to biodiesel
    Syam AM, Hamid HA, Yunus R, Rashid U
    ScientificWorldJournal, 2013;2013:268385.
    PMID: 24363616 DOI: 10.1155/2013/268385
    Many kinetics studies on methanolysis assumed the reactions to be irreversible. The aim of the present work was to study the dynamic modeling of reversible methanolysis of Jatropha curcas oil (JCO) to biodiesel. The experimental data were collected under the optimal reaction conditions: molar ratio of methanol to JCO at 6 : 1, reaction temperature of 60°C, 60 min of reaction time, and 1% w/w of catalyst concentration. The dynamic modeling involved the derivation of differential equations for rates of three stepwise reactions. The simulation study was then performed on the resulting equations using MATLAB. The newly developed reversible models were fitted with various rate constants and compared with the experimental data for fitting purposes. In addition, analysis of variance was done statistically to evaluate the adequacy and quality of model parameters. The kinetics study revealed that the reverse reactions were significantly slower than forward reactions. The activation energies ranged from 6.5 to 44.4 KJ mol⁻¹.
    Matched MeSH terms: Methanol/chemistry*; Plant Oils/chemistry*; Jatropha/chemistry*
  16. Ultrasound mediated enzymatic hydrolysis of cellulose and carboxymethyl cellulose
    Sulaiman AZ, Ajit A, Chisti Y
    Biotechnol Prog, 2013 Nov-Dec;29(6):1448-57.
    PMID: 23926080 DOI: 10.1002/btpr.1786
    A recombinant Trichoderma reesei cellulase was used for the ultrasound-mediated hydrolysis of soluble carboxymethyl cellulose (CMC) and insoluble cellulose of various particle sizes. The hydrolysis was carried out at low intensity sonication (2.4-11.8 W cm(-2) sonication power at the tip of the sonotrode) using 10, 20, and 40% duty cycles. [A duty cycle of 10%, for example, was obtained by sonicating for 1 s followed by a rest period (no sonication) of 9 s.] The reaction pH and temperature were always 4.8 and 50°C, respectively. In all cases, sonication enhanced the rate of hydrolysis relative to nonsonicated controls. The hydrolysis of CMC was characterized by Michaelis-Menten kinetics. The Michaelis-Menten parameter of the maximum reaction rate Vmax was enhanced by sonication relative to controls, but the value of the saturation constant Km was reduced. The optimal sonication conditions were found to be a 10% duty cycle and a power intensity of 11.8 W cm(-2) . Under these conditions, the maximum rate of hydrolysis of soluble CMC was nearly double relative to control. In the hydrolysis of cellulose, an increasing particle size reduced the rate of hydrolysis. At any fixed particle size, sonication at a 10% duty cycle and 11.8 W cm(-2) power intensity improved the rate of hydrolysis relative to control. Under the above mentioned optimal sonication conditions, the enzyme lost about 20% of its initial activity in 20 min. Sonication was useful in accelerating the enzyme catalyzed saccharification of cellulose.
    Matched MeSH terms: Carboxymethylcellulose Sodium/chemistry*; Cellulase/chemistry*; Cellulose/chemistry*
  17. Immobilized acclimated biomass-powdered activated carbon for the bioregeneration of granular activated carbon loaded with phenol and o-cresol
    Toh RH, Lim PE, Seng CE, Adnan R
    Bioresour Technol, 2013 Sep;143:265-74.
    PMID: 23796608 DOI: 10.1016/j.biortech.2013.05.126
    The objectives of the study are to use immobilized acclimated biomass and immobilized biomass-powdered activated carbon (PAC) as a novel approach in the bioregeneration of granular activated carbon (GAC) loaded with phenol and o-cresol, respectively, and to compare the efficiency and rate of the bioregeneration of the phenolic compound-loaded GAC using immobilized and suspended biomasses under varying GAC dosages. Bioregeneration of GAC loaded with phenol and o-cresol, respectively, was conducted in batch system using the sequential adsorption and biodegradation approach. The results showed that the bioregeneration efficiency of GAC loaded with phenol or o-cresol was basically the same irrespective of whether the immobilized or suspended biomass was used. Nonetheless, the duration for bioregeneration was longer under immobilized biomass. The beneficial effect of immobilized PAC-biomass for bioregeneration is the enhancement of the removal rate of the phenolic compounds via adsorption and the shortening of the bioregeneration duration.
    Matched MeSH terms: Carbon/chemistry*; Cresols/chemistry*; Phenol/chemistry*
  18. Fulltext Functional and preliminary characterisation of hydrocolloid from tamarillo (Solanum betaceum Cav.) puree
    Gannasin SP, Ramakrishnan Y, Adzahan NM, Muhammad K
    Molecules, 2012 Jun 05;17(6):6869-85.
    PMID: 22669042 DOI: 10.3390/molecules17066869
    Hydrocolloid from tamarillo (Solanum betaceum Cav.) puree was extracted using water and characterised for the first time. Proximate compositions of the extracted hydrocolloid were also determined. Functional characteristics such as water-holding capacity, oil-holding capacity, emulsifying activity, emulsion stability, foaming capacity and stability of the hydrocolloid were evaluated in comparison to that of commercial hydrocolloids. Its functional groups and degree of esterification were determined using Fourier Transform Infrared (FT-IR) spectroscopy. Monosaccharide profiling was done using reverse-phase high pressure liquid chromatography (RP-HPLC). Screening of various fruits for high hydrocolloid yield after water extraction resulted in tamarillo giving the highest yield. The yield on dry weight basis was 8.30%. The hydrocolloid constituted of 0.83% starch, 21.18% protein and 66.48% dietary fibre with 49.47% degree of esterification and the monosaccharides identified were mannose, ribose, rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose. Higher oil-holding capacity, emulsifying activity and emulsion stability compared to commercial hydrocolloids propose its possible application as a food emulsifier and bile acid binder. Foaming capacity of 32.19% and good foam stabilisation (79.36% of initial foam volume after 2 h of foam formation) suggest its promising application in frothy beverages and other foam based food products. These findings suggest that water-extracted tamarillo hydrocolloid can be utilised as an alternative to low methoxyl pectin.
    Matched MeSH terms: Colloids/chemistry; Fruit/chemistry; Monosaccharides/chemistry; Plant Extracts/chemistry*; Solvents/chemistry; Water/chemistry; Solanum/chemistry*; Emulsifying Agents/chemistry
  19. Fulltext A structural study of epoxidized natural rubber (ENR-50) and its cyclic dithiocarbonate derivative using NMR spectroscopy techniques
    Hamzah R, Bakar MA, Khairuddean M, Mohammed IA, Adnan R
    Molecules, 2012 Sep 12;17(9):10974-93.
    PMID: 22971583 DOI: 10.3390/molecules170910974
    A structural study of epoxidized natural rubber (ENR-50) and its cyclic dithiocarbonate derivative was carried out using NMR spectroscopy techniques. The overlapping (1)H-NMR signals of ENR-50 at δ 1.56, 1.68-1.70, 2.06, 2.15-2.17 ppm were successfully assigned. In this work, the C=S and quaternary carbon of cyclic dithiocarbonate. All other (1)H- and (13)C-NMR chemical shifts of the derivative remain unchanged with respect to the ENR-50.
    Matched MeSH terms: Carbonates/chemistry*; Epoxy Compounds/chemistry*; Rubber/chemistry*
  20. Fulltext Preparation and elastic moduli of germanate glass containing lead and bismuth
    Sidek HA, Bahari HR, Halimah MK, Yunus WM
    Int J Mol Sci, 2012;13(4):4632-41.
    PMID: 22606000 DOI: 10.3390/ijms13044632
    This paper reports the rapid melt quenching technique preparation for the new family of bismuth-lead germanate glass (BPG) systems in the form of (GeO(2))(60)-(PbO)(40-) (x)-(½Bi(2)O(3))(x) where x = 0 to 40 mol%. Their densities with respect of Bi(2)O(3) concentration were determined using Archimedes' method with acetone as a floatation medium. The current experimental data are compared with those of bismuth lead borate (B(2)O(3))(20)-(PbO)(80-) (x)-(Bi(2)O(3))(x). The elastic properties of BPG were studied using the ultrasonic pulse-echo technique where both longitudinal and transverse sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. Experimental data shows that all the physical parameters of BPG including density and molar volume, both longitudinal and transverse velocities increase linearly with increasing of Bi(2)O(3) content in the germanate glass network. Their elastic moduli such as longitudinal, shear and Young's also increase linearly with addition of Bi(2)O(3) but the bulk modulus did not. The Poisson's ratio and fractal dimensionality are also found to vary linearly with the Bi(2)O(3) concentration.
    Matched MeSH terms: Bismuth/chemistry*; Glass/chemistry*; Lead/chemistry*
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