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  1. Mesoporous carbon nitride for adsorption and fluorescence sensor of N-nitrosopyrrolidine
    Sam MS, Lintang HO, Sanagi MM, Lee SL, Yuliati L
    Spectrochim Acta A Mol Biomol Spectrosc, 2014 Apr 24;124:357-64.
    PMID: 24503155 DOI: 10.1016/j.saa.2013.12.113
    A metal-free mesoporous carbon nitride (MCN) was investigated for the first time as an adsorbent for N-nitrosopyrrolidine (NPYR), which is one of the nitrosamine pollutants. Under the same condition, the adsorption capability of the MCN was found to be higher than that of the MCM-41. Since the adsorption isotherm was consistent with Langmuir and Freundlich model equations, it was suggested that the adsorption of NPYR molecules on the MCN occurred in the form of mono-molecular layer on the heterogeneous surface sites. It was proposed that MCN with suitable adsorption sites was beneficial for the adsorption of NPYR. The evidence on the interaction between the NPYR molecules and the MCN was supported by fluorescence spectroscopy. Two excitation wavelengths owing to the terminal N-C and N=C groups were used to monitor the interactions between the emission sites of the MCN and the NPYR molecules. It was confirmed that the intensity of the emission sites was quenched almost linearly with the concentration of NPYR. This result obviously suggested that the MCN would be applicable as a fluorescence sensor for detection of the NPYR molecules. From the Stern-Volmer plot, the quenching rate constant of terminal N-C groups was determined to be ca. two times higher than that of the N=C groups on MCN, suggesting that the terminal N-C groups on MCN would be the favoured sites interacted with the NPYR. Since initial concentration can be easily recovered, the interactions of NPYR on MCN were weak and might only involve electrostatic interactions.
    Matched MeSH terms: Temperature
  2. Fulltext Diversity of global rice markets and the science required for consumer-targeted rice breeding
    Calingacion M, Laborte A, Nelson A, Resurreccion A, Concepcion JC, Daygon VD, et al.
    PLoS One, 2014;9(1):e85106.
    PMID: 24454799 DOI: 10.1371/journal.pone.0085106
    With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a 'one size fits all' crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market.
    Matched MeSH terms: Temperature
  3. Purification, characterization and comparative studies of spray-dried bacterial cellulose microparticles
    Amin MC, Abadi AG, Katas H
    Carbohydr Polym, 2014 Jan;99:180-9.
    PMID: 24274495 DOI: 10.1016/j.carbpol.2013.08.041
    Bacterial cellulose (BC) is a biopolymer with significant potential for the development of novel materials. This work aimed to prepare and characterize BC powders from nata de coco, and assess the possible enhancement of the powder properties by spray drying. Therefore, BC powders prepared by acid treatment and mechanical processing were spray-dried, and characterized according to their morphology, flowability, thermal stability, water retention capacity, and compared with commercial microcrystalline cellulose (MCC). The powders redispersibility and suspensions rheology were also evaluated. SEM showed that spray-dried BC microparticles exhibited semispherical shape and had flow rate of 4.23 g s(-1) compared with 0.52 g s(-1) for MCC. Particle size analysis demonstrated that spray-dried BC microparticles could be redispersed. TGA showed that BC samples had higher thermal stability than MCC. Water retention capacities of BC samples were greater than MCC. These findings provide new insight on the potential applications of spray-dried BC as a promising pharmaceutical excipient.
    Matched MeSH terms: Hot Temperature
  4. A mathematical framework for minimally invasive tumor ablation therapies
    Hall SK, Ooi EH, Payne SJ
    Crit Rev Biomed Eng, 2014;42(5):383-417.
    PMID: 25745803
    Minimally invasive tumor ablations (MITAs) are an increasingly important tool in the treatment of solid tumors across multiple organs. The problems experienced in modeling different types of MITAs are very similar, but the development of mathematical models is mostly performed in isolation according to modality. Fundamental research into the modeling of specific types of MITAs is indeed required, but to choose the optimal treatment for an individual the primary clinical requirement is to have reliable predictions for a range of MITAs. In this review of the mathematical modeling of MITAs 4 modalities are considered: radiofrequency ablation, microwave ablation, cryoablation, and irreversible electroporation. The similarities in the mathematical modeling of these treatments are highlighted, and the analysis of the models within a general framework is discussed. This will aid in developing a deeper understanding of the sensitivity of MITA models to physiological parameters and the impact of uncertainty on predictions of the ablation zone. Through robust validation and analysis of the models it will be possible to choose the best model for a given application. This is important because many different models exist with no objective comparison of their performance. The collection of relevant in vivo experimental data is also critical to parameterize such models accurately. This approach will be necessary to translate the field into clinical practice.
    Matched MeSH terms: Temperature
  5. Temporal variability and climatology of hydrodynamic, water property and water quality parameters in the West Johor Strait of Singapore
    Behera MR, Chun C, Palani S, Tkalich P
    Mar Pollut Bull, 2013 Dec 15;77(1-2):380-95.
    PMID: 24139643 DOI: 10.1016/j.marpolbul.2013.09.043
    The study presents a baseline variability and climatology study of measured hydrodynamic, water properties and some water quality parameters of West Johor Strait, Singapore at hourly-to-seasonal scales to uncover their dependency and correlation to one or more drivers. The considered parameters include, but not limited by sea surface elevation, current magnitude and direction, solar radiation and air temperature, water temperature, salinity, chlorophyll-a and turbidity. FFT (Fast Fourier Transform) analysis is carried out for the parameters to delineate relative effect of tidal and weather drivers. The group and individual correlations between the parameters are obtained by principal component analysis (PCA) and cross-correlation (CC) technique, respectively. The CC technique also identifies the dependency and time lag between driving natural forces and dependent water property and water quality parameters. The temporal variability and climatology of the driving forces and the dependent parameters are established at the hourly, daily, fortnightly and seasonal scales.
    Matched MeSH terms: Temperature
  6. Porphyromonas gingivalis peptidylarginine deiminase substrate specificity
    Abdullah SN, Farmer EA, Spargo L, Logan R, Gully N
    Anaerobe, 2013 Oct;23:102-8.
    PMID: 23856045 DOI: 10.1016/j.anaerobe.2013.07.001
    While a group of oral commensals have been implicated in the aetiology of chronic periodontitis; the asaccharolytic Gram negative anaerobe Porphyromonas gingivalis is most commonly reported to be associated with severe forms of the disease. Although a variety of human tissues can produce a number of peptidylarginine deiminase (PAD), enzymes that convert peptide bound arginine residues to citrulline, P. gingivalis is one of the few prokaryotes known to express PAD. Protein and peptide citrullination are important in the development of rheumatoid arthritis and in recent years a number of authors have suggested a possible link between periodontitis and rheumatoid arthritis (RA). Indeed, some have linked P. gingivalis directly to RA via the action of PAD. Accordingly, the prime purpose of this study was to further characterise PAD in P. gingivalis cells particular emphasis on substrate specificity, using arginine containing peptides and RA relevant proteins.
    Matched MeSH terms: Temperature
  7. Fulltext Optimization of extraction parameters by using response surface methodology, purification, and identification of anthocyanin pigments in Melastoma malabathricum fruit
    Anuar N, Mohd Adnan AF, Saat N, Aziz N, Mat Taha R
    ScientificWorldJournal, 2013;2013:810547.
    PMID: 24174918 DOI: 10.1155/2013/810547
    Anthocyanins not just have various benefits in food industry but also have been used as natural colourants in cosmetic, coating products and as potential natural photosensitizers in solar cell. Thus, the main purpose of this study was to obtain information on the maximum yield of anthocyanin that can be recovered from Melastoma malabathricum fruit. Factors such as extraction temperature, extraction time, and solid to liquid ratio were identified to be significantly affecting anthocyanin extraction efficiency. By using three-level three-factor Box-Behnken design, the optimized conditions for anthocyanin extraction by acidified methanol (R (2) = 0.972) were temperature of 60°C, time of 86.82 min, and 0.5 : 35 (g/mL) solid to liquid ratio while the optimum extraction conditions by acidified ethanol (R (2) = 0.954) were temperature of 60°C, time of 120 min, and 0.5 : 23.06 (g/mL) solid to liquid ratio. The crude anthocyanin extract was further purified by using Amberlite XAD-7 and Sephadex LH-20 column chromatography. Identification of anthocyanins revealed the presence of cyanidin dihexoside, cyanidin hexoside, and delphinidin hexoside as the main anthocyanins in M. malabathricum fruit.
    Matched MeSH terms: Temperature
  8. Influence of temperature on survival and water relations of Paederus fuscipes (Coleoptera: Staphylinidae)
    Bong LJ, Neoh KB, Jaal Z, Lee CY
    J Med Entomol, 2013 Sep;50(5):1003-13.
    PMID: 24180105
    The effects of four temperatures (15, 23.5, 28, and 35 degrees C) on the biological characteristics of the rove beetle Paederus fuscipes Curtis were studied, and its cuticular permeability also was measured. Specimens successfully developed to adulthood at each temperature tested, but development time of each preadult stage significantly decreased with increasing temperature. Both egg and L1 stages required at least 80 degree days above a threshold of approximately 10 degrees C to develop to the subsequent stage. The lengthy development time and high survival rate of preadults at 15 degrees C suggests that P. fuscipes can survive in a harsh environment during cold weather by hibernating, and this ability could allow preadults to succeed ecologically in temperate countries. However, adult longevity was short, and no fecundity was recorded at 15 degrees C. At 28 degrees C, P. fuscipes exhibited a high survival rate of adults, which had a longer life span and high fecundity; thus, the population had the highest intrinsic rate of increase (0.0788 +/- 0.0051 d(-1)) and the shortest mean generation time (48.57 +/- 1.43 d) at 28 degrees C. At this temperature, the population might reach a size that could facilitate invasion into residential areas. However, in the absence of a hygric environment, P. fuscipes was unable to survive despite favorable temperature. Unlike in adults and pupae, high cuticular permeability values were found in the larval stages. This indicates that larvae are highly susceptible to desiccation, and it explains why the distribution of P. fuscipes is restricted to moist habitats.
    Matched MeSH terms: Temperature
  9. Fulltext Enhanced production, purification, characterization and mechanism of action of salivaricin 9 lantibiotic produced by Streptococcus salivarius NU10
    Barbour A, Philip K, Muniandy S
    PLoS One, 2013;8(10):e77751.
    PMID: 24147072 DOI: 10.1371/journal.pone.0077751
    BACKGROUND: Lantibiotics are small lanthionine-containing bacteriocins produced by lactic acid bacteria. Salivaricin 9 is a newly discovered lantibiotic produced by Streptococcus salivarius. In this study we present the mechanism of action of salivaricin 9 and some of its properties. Also we developed new methods to produce and purify the lantibiotic from strain NU10.

    METHODOLOGY/PRINCIPAL FINDINGS: Salivaricin 9 was found to be auto-regulated when an induction assay was applied and this finding was used to develop a successful salivaricin 9 production system in liquid medium. A combination of XAD-16 and cation exchange chromatography was used to purify the secondary metabolite which was shown to have a molecular weight of approximately 3000 Da by SDS-PAGE. MALDI-TOF MS analysis indicated the presence of salivaricin 9, a 2560 Da lantibiotic. Salivaricin 9 is a bactericidal molecule targeting the cytoplasmic membrane of sensitive cells. The membrane permeabilization assay showed that salivaricin 9 penetrated the cytoplasmic membrane and induced pore formation which resulted in cell death. The morphological changes of test bacterial strains incubated with salivaricin 9 were visualized using Scanning Electron Microscopy which confirmed a pore forming mechanism of inhibition. Salivaricin 9 retained biological stability when exposed to high temperature (90-100°C) and stayed bioactive at pH ranging 2 to 10. When treated with proteinase K or peptidase, salivaricin 9 lost all antimicrobial activity, while it remained active when treated with lyticase, catalase and certain detergents.

    CONCLUSION: The mechanism of antimicrobial action of a newly discovered lantibiotic salivaricin 9 was elucidated in this study. Salivaricin 9 penetrated the cytoplasmic membrane of its targeted cells and induced pore formation. This project has given new insights on lantibiotic peptides produced by S. salivarius isolated from the oral cavities of Malaysian subjects.

    Matched MeSH terms: Temperature
  10. Temperature-mediated absorption of phenylmercuric nitrate on polyethylene and polypropylene containers in chloramphenicol eye drops
    Charoo N, Chiew M, Tay A, Lian L
    Cutan Ocul Toxicol, 2014 Sep;33(3):242-6.
    PMID: 24147942 DOI: 10.3109/15569527.2013.837058
    The aim of this work was to find the effect of temperature and manufacturing source of phenylmercuric nitrate (PMN) on PMN absorption on low-density polyethylene (LDPE) and polypropylene containers in chloramphenicol eye drops. Two factorial experiments were designed to study the effect of temperature on PMN assay in chloramphenicol eye drops stored in LDPE and prepared from two different PMN sources. PMN source had no effect on PMN assay at 2-8 °C, however at stress conditions (30 °C/75%RH) for 3 weeks, the effect of PMN source on PMN assay was found significant (p 
    Matched MeSH terms: Temperature
  11. Biosorption of As (III) by non-living biomass of an arsenic-hypertolerant Bacillus cereus strain SZ2 isolated from a gold mining environment: equilibrium and kinetic study
    Mohd Bahari Z, Ali Hamood Altowayti W, Ibrahim Z, Jaafar J, Shahir S
    Appl Biochem Biotechnol, 2013 Dec;171(8):2247-61.
    PMID: 24037600 DOI: 10.1007/s12010-013-0490-x
    The ability of non-living biomass of an arsenic-hypertolerant Bacillus cereus strain SZ2 isolated from a gold mining environment to adsorb As (III) from aqueous solution in batch experiments was investigated as a function of contact time, initial As (III) concentration, pH, temperature and biomass dosage. Langmuir model fitted the equilibrium data better in comparison to Freundlich isotherm. The maximum biosorption capacity of the sorbent, as obtained from the Langmuir isotherm, was 153.41 mg/g. The sorption kinetic of As (III) biosorption followed well the pseudo-second-order rate equation. The Fourier transform infrared spectroscopy analysis indicated the involvement of hydroxyl, amide and amine groups in As (III) biosorption process. Field emission scanning electron microscopy-energy dispersive X-ray analysis of the non-living B. cereus SZ2 biomass demonstrated distinct cell morphological changes with significant amounts of As adsorbed onto the cells compared to non-treated cells. Desorption of 94 % As (III) was achieved at acidic pH 1 showing the capability of non-living biomass B. cereus SZ2 as potential biosorbent in removal of As (III) from arsenic-contaminated mining effluent.
    Matched MeSH terms: Temperature
  12. Effects of ascorbic acid on PVS2 cryopreservation of Dendrobium Bobby Messina's PLBs supported with SEM analysis
    Antony JJ, Keng CL, Mahmood M, Subramaniam S
    Appl Biochem Biotechnol, 2013 Sep;171(2):315-29.
    PMID: 23832189 DOI: 10.1007/s12010-013-0369-x
    Regrowth of the cryopreserved protocorm-like bodies (PLBs) of Dendrobium Bobby Messina was assessed based on the plant vitrification solution 2 (PVS2) optimisation conditions. The optimized protocol obtained based on TTC spectrophotometrical analysis and growth recovery were 3-4 mm of PLBs size precultured in 0.2 M sucrose for 1 day, treated with a mixture of 2 M glycerol and 0.4 M sucrose supplemented with half-strength liquid MS media at 25 °C for 20 min and subsequently dehydrated with PVS2 at 0 °C for 20 min prior to storage in liquid nitrogen. Following rapid warming in a water bath at 40 °C for 90 s, PLBs were treated with unloading solution containing half-strength liquid MS media supplemented with 1.2 M sucrose. Subsequently, the PLBs were cultured on half-strength semi-solid MS media supplemented with 2 % (w/v) sucrose without any growth regulators and resulted in 40 % growth recovery. In addition, ascorbic acid treatment was used to evaluate the regeneration process of cryopreserved PLBs. However, growth recovery rates of non-cryopreserved and cryopreserved PLBs were 30 and 10 % when 0.6 mM ascorbic acid was added. Scanning electron microscopy analysis indicates that there are not much damages observed on both cryopreserved and non-cryopreserved PLBs in comparison to PLBs stock culture.
    Matched MeSH terms: Temperature
  13. Chemical modification of chitin by grafting with polystyrene using ammonium persulfate initiator
    Abu Naim A, Umar A, Sanagi MM, Basaruddin N
    Carbohydr Polym, 2013 Nov 6;98(2):1618-23.
    PMID: 24053848 DOI: 10.1016/j.carbpol.2013.07.054
    Chitin was successfully grafted with polystyrene by free radical mechanism using ammonium persulfate (APS) initiator. The reaction was carried out in aqueous medium. The effect of pH, chitin:monomer weight ratio, APS, reaction time and reaction temperature were investigated. The results showed that the optimum conditions for grafting of polystyrene were found as follows: pH 7, chitin:monomer weight ratio of 1:3, 0.4 g of APS, reaction temperature of 60 °C and reaction time 2 h. The graft copolymer was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA) and differential scanning electron microscopy (DSC). Gel permeation chromatography (GPC) analysis carried out on the hydrolyzed graft copolymer showed that the Mn and Mw were 6.3395×10(4) g/mol and 1.69283×10(5) g/mol, respectively, with polydispersity index of 2.7.
    Matched MeSH terms: Temperature
  14. Colour, phenolic content and antioxidant capacity of some fruits dehydrated by a combination of different methods
    Chong CH, Law CL, Figiel A, Wojdyło A, Oziembłowski M
    Food Chem, 2013 Dec 15;141(4):3889-96.
    PMID: 23993562 DOI: 10.1016/j.foodchem.2013.06.042
    The objective of this study was to improve product quality of dehydrated fruits (apple, pear, papaya, mango) using combined drying techniques. This involved investigation of bioactivity, colour, and sensory assessment on colour of the dried products as well as the retention of the bio-active ingredients. The attributes of quality were compared in regard to the quality of dehydrated samples obtained from continuous heat pump (HP) drying technique. It was found that for apple, pear and mango the total colour change (ΔE) of samples dried using continuous heat pump (HP) or heat pump vacuum-microwave (HP/VM) methods was lower than of samples dried by other combined methods. However, for papaya, the lowest colour change exhibited by samples dried using hot air-cold air (HHC) method and the highest colour change was found for heat pump (HP) dehydrated samples. Sensory evaluation revealed that dehydrated pear with higher total colour change (ΔE) is more desirable because of its golden yellow appearance. In most cases the highest phenol content was found from fruits dried by HP/VM method. Judging from the quality findings on two important areas namely colour and bioactivity, it was found that combined drying method consisted of HP pre-drying followed by VM finish drying gave the best results for most dehydrated fruits studied in this work as the fruits contain first group of polyphenol compounds, which preferably requires low temperature followed by rapid drying strategy.
    Matched MeSH terms: Hot Temperature
  15. Effect of extraction conditions on the yield and chemical properties of pectin from cocoa husks
    Chan SY, Choo WS
    Food Chem, 2013 Dec 15;141(4):3752-8.
    PMID: 23993545 DOI: 10.1016/j.foodchem.2013.06.097
    Different extraction conditions were applied to investigate the effect of temperature, extraction time and substrate-extractant ratio on pectin extraction from cocoa husks. Pectin was extracted from cocoa husks using water, citric acid at pH 2.5 or 4.0, or hydrochloric acid at pH 2.5 or 4.0. Temperature, extraction time and substrate-extractant ratio affected the yields, uronic acid contents, degrees of methylation (DM) and degrees of acetylation (DA) of the extracted pectins using the five extractants differently. The yields and uronic acid contents of the extracted pectins ranged from 3.38-7.62% to 31.19-65.20%, respectively. The DM and DA of the extracted pectins ranged from 7.17-57.86% to 1.01-3.48%, respectively. The highest yield of pectin (7.62%) was obtained using citric acid at pH 2.5 [1:25 (w/v)] at 95 °C for 3.0 h. The highest uronic acid content (65.20%) in the pectin was obtained using water [1:25 (w/v)] at 95 °C for 3.0 h.
    Matched MeSH terms: Temperature
  16. Possible role of inter-domain salt bridges in oligopeptidase B from Trypanosoma brucei: critical role of Glu172 of non-catalytic β-propeller domain in catalytic activity and Glu490 of catalytic domain in stability of OPB
    Fukumoto J, Ismail NI, Kubo M, Kinoshita K, Inoue M, Yuasa K, et al.
    J. Biochem., 2013 Nov;154(5):465-73.
    PMID: 23946505 DOI: 10.1093/jb/mvt077
    Oligopeptidase B (OPB) is a member of the prolyl oligopeptidase (POP) family of serine proteases. OPB in trypanosomes is an important virulence factor and potential pharmaceutical target. Characteristic structural features of POP family members include lack of a propeptide and presence of a β-propeller domain (PD), although the role of the β-PD has yet to be fully understood. In this work, residues Glu(172), Glu(490), Glu(524) and Arg(689) in Trypanosoma brucei OPB (Tb OPB), which are predicted to form inter-domain salt bridges, were substituted for Gln and Ala, respectively. These mutants were evaluated in terms of catalytic properties and stability. A negative effect on kcat/Km was obtained following mutation of Glu(172) or Arg(689). In contrast, the E490Q mutant exhibited markedly decreased thermal stability, although this mutation had less effect on catalytic properties compared to the E172Q and R689A mutants. Trypsin digestion showed that the boundary regions between the β-PD and catalytic domains (CDs) of the E490Q mutant are unfolded with heat treatment. These results indicated that Glu(490) in the CD plays a role in stabilization of Tb OPB, whereas Glu(172) in the β-PD is critical for the catalytic activity of Tb OPB.
    Matched MeSH terms: Hot Temperature
  17. Fulltext Optimal binary solvent extraction system for phenolic antioxidants from mengkudu (Morinda citrifolia) fruit
    Thoo YY, Ho SK, Abas F, Lai OM, Ho CW, Tan CP
    Molecules, 2013 Jun 14;18(6):7004-22.
    PMID: 23771061 DOI: 10.3390/molecules18067004
    Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity from Morinda citrifolia fruit via modification of the ethanol concentration, extraction time and extraction temperature at minimal processing cost. The optimised conditions yielded values of 881.57 ± 17.74 mg GAE/100 g DW for TPC, 552.53 ± 34.16 mg CE/100 g DW for TFC, 799.20 ± 2.97 µmol TEAC/100 g DW for ABTS and 2,317.01 ± 18.13 µmol TEAC/100 g DW for DPPH were 75% ethanol, 40 min of time and 57 °C. The four responses did not differ significantly (p > 0.05) from predicted values, indicating that models obtained are suitable to the optimisation of extraction conditions for phenolics from M. citrifolia. The relative amounts of flavonoids were 0.784 ± 0.01 mg quercetin/g of extract and 1.021 ± 0.04 mg rutin/g of extract. On the basis of the results obtained, M. citrifolia extract can be used as a valuable bioactive source of natural antioxidants.
    Matched MeSH terms: Temperature
  18. Physico-chemical characterisation of the fat from red-skin rambutan (Nephellium lappaceum L.) seed
    Manaf YN, Marikkar JM, Long K, Ghazali HM
    J Oleo Sci, 2013;62(6):335-43.
    PMID: 23728324
    The seeds (6.9±0.2% by weight of fruit) of the red-skin rambutan (Nephelium lappaceum L.) contain a considerable amount of crude fat (38.0±4.36%) and thus, the aim of the study was to determine the physico-chemical properties of this fat for potential applications. The iodine and saponification values, and unsaponifiable matter and free fatty acid contents of the seed fat were 50.27 g I2/100g fat, 182.1 mg KOH/g fat, 0.8% and 2.1%, respectively. The fat is pale yellow with a Lovibond color index of 3.1Y+1.1R. The fatty acid profile indicates an almost equal proportion of saturated (49.1%) and unsaturated (50.9%) fatty acids, where oleic (42.0%) and arachidic (34.3%) acids were the most dominant fatty acids. It also contained small amounts of stearic (8.0%), palmitic (4.6%), gadoleic (5.9%), linoleic (2.2%), behenic (2.1%) palmitoleic (0.7%) myristic (0.1%) and erucic (0.1%) acids. HPLC analysis showed that the fat comprised mainly unknown triacylglycerols (TAG) with high retention times indicating they have higher carbon numbers compared with many vegetable oils. The fat has melting and cooling points of 44.2°C and -42.5°C, respectively, making it a semi-solid at room temperature. The solid content at 0°C was 53.5% and the fat melted completely at 40°C. z-Nose analysis showed that the presence of high levels of volatile compounds in red-skin rambutan seed and seed fat.
    Matched MeSH terms: Transition Temperature
  19. Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process
    Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M
    Bioresour Technol, 2013 Jun;138:124-30.
    PMID: 23612170 DOI: 10.1016/j.biortech.2013.03.179
    In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively.
    Matched MeSH terms: Temperature
  20. Fulltext Reduction of saltiness and acrylamide levels in palm sugar-like flavouring through buffer modification and the addition of calcium chloride
    Tan PY, Tan CP, Abas F, Ho CW, Mustapha WA
    Molecules, 2013 Jun 10;18(6):6792-803.
    PMID: 23752466 DOI: 10.3390/molecules18066792
    Palm sugar-like flavouring (PSLF) is a type of flavour product that is formed by heating amino acids and sugar under specific heating conditions. Unfortunately, PSLF has a salty taste and contains high amounts of acrylamide. Hence, the objective of this research was to reduce saltiness and acrylamide without negatively affecting the aroma properties of PSLF. A decrease in the sodium phosphate (NaHPO₄) buffer concentration from 0.20 to 0.02 M was found to reduce sodium to approximately 15% of the level found in original PSLF. A further decrease (~25%) in the sodium content was achieved by removing monobasic sodium phosphate (NaH₂PO₄) from the buffer system. Meanwhile, the addition of CaCl₂ at 20-40 mg/L reduced the acrylamide content in PSLF by as much as 58%. A CaCl₂ concentration of 20 mg/mL was most favourable as it most efficiently suppressed acrylamide formation while providing an acceptably high flavour yield in PSLF. In view of the high acrylamide content in PSLF, additional work is necessary to further reduce the amount of acrylamide by controlling the asparagine concentration in the precursor mixture.
    Matched MeSH terms: Hot Temperature
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