Displaying publications 81 - 100 of 137 in total

Abstract:
Sort:
  1. Fungal solid state culture of palm kernel cake
    Iluyemi FB, Hanafi MM, Radziah O, Kamarudin MS
    Bioresour Technol, 2006 Feb;97(3):477-82.
    PMID: 16216731
    Palm kernel cake (PKC), an agro-industrial by-product used extensively in the animal feed industry, has limited use in fish feeds due to its high fiber and low protein contents. In this study, PKC was processed under solid state culture conditions with five fungal strains and the effect of this fungal culturing on the amino acid, fatty acid, cellulose and hemicellulose fractions was evaluated. Fungal strains used were Sclerotium rolfsii, Trichoderma harzianum, Trichoderma longiobrachiatum, Trichoderma koninggi and Aspergillus niger. Fungal growth was carried out at 50% moisture level and 1% inoculum level for 7 days. A significant increase in protein content from 18.76% to 32.79% was obtained by growing T. longibrachiatum on PKC. Cellulose level decreased significantly from 28.31% to 12.11% for PKC cultured with T. longibrachiatum, and hemicellulose from 37.03% to 19.01% for PKC cultured with A. niger. Fungal culturing of PKC brought about an increase in the level of unsaturated- and a decrease in the level of the saturated-fatty acids.
    Matched MeSH terms: Chromatography, Gas
  2. Gas chromatographic determination of eugenol in ethanol extract of cloves
    Myint S, Daud WR, Mohamad AB, Kadhum AA
    J Chromatogr B Biomed Appl, 1996 Apr 26;679(1-2):193-5.
    PMID: 8998560
    An ethanolic extract of cloves was analyzed by gas chromatography directly to identify eugenol and other major phenolic compounds without previous separation of other components. Separation was performed on a fused-silica capillary column of 30 m x 0.53 mm I.D., 0.53 microns film thickness. The detector was a flame ionization detector. Helium gas at a flow-rate of 3 ml/min was used as a carrier gas. The analysis were performed with linear temperature programming. Nine components were detected and special attention was given to the major phenolic compound, eugenol.
    Matched MeSH terms: Chromatography, Gas/methods
  3. Chemical composition and antioxidant properties of candlenut oil extracted by supercritical CO2
    Siddique BM, Ahmad A, Alkarkhi AF, Ibrahim MH, K MO
    J Food Sci, 2011 May;76(4):C535-42.
    PMID: 22417332 DOI: 10.1111/j.1750-3841.2011.02146.x
    Candlenut oil was extracted using supercritical CO(2) (SC-CO(2)) with an optimization of parameters, by the response surface methodology. The ground candlenut samples were treated in 2 different ways, that is, dried in either a heat oven (sample moisture content of 2.91%) or dried in a vacuum oven (sample moisture content of 1.98%), before extraction. An untreated sample (moisture content of 4.87%) was used as a control. The maximum percentage of oil was extracted from the heat-oven-dried sample (77.27%), followed by the vacuum-oven-dried sample (74.32%), and the untreated sample (70.12%). At an SC-CO(2) pressure of 48.26 Mpa and 60 min of extraction time, the optimal temperatures for extraction were found to be 76.4 °C, 73.9 °C, and 70.6 °C for the untreated, heat-oven-dried, and vacuum-oven-dried samples, respectively. The heat-oven-dried sample contains the highest percentage of linoleic acid, followed by the untreated and vacuum-oven-dried samples. The antiradical activity of candlenut oil corresponded to an IC(50) value of 30.37 mg/mL.
    Matched MeSH terms: Chromatography, Gas
  4. Chemical compositions of the rhizome oils of two Alpinia species of Malaysia
    Sirat HM, Basar N, Jani NA
    Nat Prod Res, 2011 Jun;25(10):982-6.
    PMID: 21644178 DOI: 10.1080/14786419.2010.529079
    The essential oils obtained by hydrodistillation of the rhizomes of Alpinia aquatica Rosc. syn. Alpinia melanocarpa and Alpinia malaccensis Roscoe were analysed by capillary gas chromatography and gas chromatography-mass spectrometry. Eighteen compounds, representing 98.4% of the essential oil were identified in A. aquatica rhizome oil, with β-sesquiphellandrene in 36.5% being the major constituent, while 20 compounds representing 99.7% of the rhizome oil of A. malaccensis were identified, among which methyl (E)-cinnamate (78.2%) was the major constituent.
    Matched MeSH terms: Chromatography, Gas
  5. Fulltext Antifungal activity of the bark and leaf oils of Cinnamomum verum J.S. Presl. alone and in combination against various fungi
    Moharm, Bushra Abdulkarim, Ibrahim Jantan, Santhanam, Jacinta, Jamia Azdina Jamal
    Jurnal Sains Kesihatan Malaysia, 2005;3(1):1-12.
    MyJurnal
    The leaf and bark oils of Cinnamomum verum J.S. Presl. were examined for their antifungal activity against 6 dermatophytes (Trichophyton rubrum, T. mentagrophytes, T. tonsurans, Microsporum canis, M. gypseum and M. audouini), one filamentous fungi (Aspergillus fumigatus) and 5 strains of yeasts (Candida albicans, Ca. glabrata, Ca. tropicalis, Ca. parapsilosis and Crytococcus neoformans) by using the broth microdilution method. The antifungal activities of 4 standard compounds (cinnamaldehyde, eugenol, linalool and a-terpineol) which were major constituents in the oils were also investigated in an effort to correlate the effectiveness of the oils with those of the components of the oils. The combined antifungal effect of the oils against M. canis, M. gypseum and Cr. neoformans was investigated by the checkerboard assay. Isobolograms were constructed and Fractional Inhibitory Concentrations Index (FICI) were calculated to determine the combination effects between the oils. The chemical composition of the oils was analyzed by gas chromatography (GC) and gas chromatography- mass spectrometry (GC-MS). The oils showed strong activity against all the tested fungi with Minimum Inhibition Concentration (MIC) values ranging from 0.04 to 0.31 mg/ml. Cinnamaldehyde which was the most abundant component of the bark oil of C. verum showed the strongest activity against all the fungi studied. Based on the results of the assay on standard samples, it may be that the high levels of cinnamaldehyde and eugenol in the oils and in combination with the minor components could be responsible for the high antifungal activity of the oils. The antifungal effect of the leaf and bark oils of C. verum in combination against the tested fungi was not synergistic. However, the effect was additive against M. gypseum and antagonistic against Cr. neoformans and M. canis.
    Matched MeSH terms: Chromatography, Gas
  6. Fatty acid compositions in local sea cucumber, Stichopus chloronotus, for wound healing
    Fredalina BD, Ridzwan BH, Abidin AA, Kaswandi MA, Zaiton H, Zali I, et al.
    Gen. Pharmacol., 1999 Oct;33(4):337-40.
    PMID: 10523072
    Fatty acid profile from crude extracts of local sea cucumber Stichopus chloronotus was determined using gas chromatography (GC) technique. The extracts were prepared separately in methanol, ethanol, phosphate buffer saline (PBS), and distilled water as part of our study to look at the affinity of these solvents in extracting the lipid from sea cucumber. The PBS and distilled water extractions indicate water-soluble components, while the organic fractions are extracted in methanol and ethanol as organic solvents. Furthermore, water extraction is the conventional method practiced in Malaysia. In our analysis the C14:0 (myristic), C16:0 (palmitic), C18:0 (stearic), C18:2 (linoleic), C20:0 (arachidic), and C20:5 (eicosapentaenoic, EPA) were significantly different (p < 0.01) in the four solvent extractions. However, the PBS extraction contained a much higher percentage of EPA (25.69%) compared to 18.89% in ethanol, 7.84% in distilled water, and only 5.83% in methanol, and variances were significantly different (p < 0.01 ). On the other hand, C22:6 (docosahexaenoic acid or DHA) is much higher in water extraction (57.55%), in comparison to the others where only 3.63% in PBS and 1.20% in methanol, and this difference is significant at p < 0.01. No DHA was detected in ethanol extractions. Subsequently, C18:1 (oleic acid) was only detected in PBS (21.98%) and water extraction (7.50%). It is interesting that palmitic acid, C16:() was higher in methanol (20.82%) and ethanol (2.18%), while 12.55% was detected in PBS and only 2.20% in water extraction: and again this was significantly different at p < 0.01. Although our results have shown that all four solvents were different in terms of their ability to extract fatty acids, the major component for tissue repair was well preserved. Probably this is one of the important precocious steps when working with a delicate sea cucumber, in both experimental and/or at the preparative stages. Freshness of the sea cucumber samples is important when undertaking this type of experiment. Finally, we believe that the local sea cucumber S. chloronotus contains all the fatty acids required to play a potential active role in tissue repair.
    Matched MeSH terms: Chromatography, Gas
  7. Effect of repeatedly heated palm olein on blood pressure-regulating enzymes activity and lipid peroxidation in rats
    Leong XF, Salimon J, Mustafa MR, Jaarin K
    Malays J Med Sci, 2012 Jan;19(1):20-9.
    PMID: 22977371
    BACKGROUND: Oxidative stress is associated with the pathogenesis of cardiovascular diseases. The process of deep-fat frying in dietary cooking oil plays a role in the generation of free radicals. In this study, palm olein heated to 180 °C was tested for its effect on the activity of blood pressure-regulating enzymes and lipid peroxidation.

    METHODS: Forty-two adult male Sprague-Dawley rats were equally assigned into 6 groups.The first group was fed with normal rat chow as the control group, and the subsequent groups were fed with rat chow fortified with 15% weight/weight of the following: fresh palm olein, palm olein heated once, palm olein heated twice, palm olein heated 5 times, or palm olein heated 10 times. The duration of feeding was 6 months. Fatty acid analyses of oil were performed using gas chromatography. Peroxide values were determined using standard titration. Plasma was collected for biochemical analyses.

    RESULTS: Repeatedly heated palm olein increased the levels of peroxide, angiotensin-converting enzyme, and lipid peroxidation as well as reduced the level of heme oxygenase. Fresh palm olein and palm olein heated once had lesser effects on lipid peroxidation and a better effect on the activity of blood pressure-regulating enzymes than repeatedly heated palm olein.

    CONCLUSION: Repeatedly heated palm olein may negatively affect the activity of blood pressure-regulating enzymes and increase lipid peroxidation.

    Matched MeSH terms: Chromatography, Gas
  8. Method development for determination of fluroxypyr in soil
    Halimah M, Tan YA, Ismail BS
    J Environ Sci Health B, 2004;39(5-6):765-77.
    PMID: 15620085
    Four methods were developed for the analysis of fluroxypyr in soil samples from oil palm plantations. The first method involved the extraction of the herbicide with 0.05 M NaOH in methanol followed by purification using acid base partition. The concentrated material was subjected to derivatization and then cleaning process using a florisil column and finally analyzed by gas chromatography (GC) equipped with electron capture detector (ECD). By this method, the recovery of fluroxypyr from the spiked soil ranged from 70 to 104% with the minimum detection limit at 5 microg/kg. The second method involved solid liquid extraction of fluroxypyr using a horizontal shaker followed by quantification using high performance liquid chromatography (HPLC) equipped with UV detector. The recovery of fluroxypyr using this method, ranged from 80 to 120% when the soil was spiked with fluroxypyr at 0.1-0.2 microg/g soil. In the third method, the recovery of fluroxypyr was determined by solid liquid extraction using an ultrasonic bath. The recovery of fluroxypyr at spiking levels of 4-50 microg/L ranged from 88 to 98% with relative standard deviations of 3.0-5.8% with a minimum detection limit of 4 microg/kg. In the fourth method, fluroxypyr was extracted using the solid liquid extraction method followed by the cleaning up step with OASIS HLB (polyvinyl dibenzene). The recovery of fluroxypyr was between 91 and 95% with relative standard deviations of 4.2-6.2%, respectively. The limit of detection in method 4 was further improved to 1 pg/kg. When the weight of soil used was increased 4 fold, the recovery of fluroxypyr at spiking level of 1-50 microg/kg ranged from 82-107% with relative standard deviations of 0.5-4.7%.
    Matched MeSH terms: Chromatography, Gas
  9. Fulltext Impact of chicken nugget presence on the degradation of canola oil during frying
    Ali, M.A., Daud, A.S.M., Latip, R.A., Othman, N.H., Islam, M.A.
    International Food Research Journal, 2014;21(3):1119-1124.
    MyJurnal
    The aim of the present study was to evaluate the effect of chicken nuggets addition on the degradation of canola oil during frying compared to the changes occurring when the same frying medium was simply heated at frying temperature as control. Heating or frying test was carried out at 185±5oC using electric fryer for 8 h/day for 3 consecutive days and the oil sample was collected every 4 h. The changes in fatty acids composition and physicochemical properties of the oil samples during frying and controlled heating experiments were monitored. In this study, refractive index, free fatty acid content, peroxide value, p-anisidine value, polar compounds and viscosity of the oils all increased, whereas iodine value and C18:2/C16:0 ratio decreased as heating or frying progressed. The percentage of linoleic acid tended to decrease, whereas the percentages of palmitic acid increased. Gas chromatography analysis revealed that adding chicken nuggets to heated canola oil led to higher decrease in the ratio of C18.2/C16:0 compared to what was measured when the fat alone was heated at frying temperature. The presence of chicken nuggets accelerates the formation of polymerization products and polar compounds in canola oil during frying.
    Matched MeSH terms: Chromatography, Gas
  10. Validation of thermally assisted hydrolysis and methylation-gas chromatography for rapid and direct compositional analysis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) in whole bacterial cells
    Baidurah S, Murugan P, Joyyi L, Fukuda J, Yamada M, Sudesh K, et al.
    J Chromatogr A, 2016 Nov 04;1471:186-191.
    PMID: 27769532 DOI: 10.1016/j.chroma.2016.10.019
    Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of an organic alkali was validated for the compositional analysis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] accumulated in whole bacterial cells. Recombinant Cupriavidus necator Re2058/pCB113 was grown in a batch fermentation with different concentration of palm oil and fructose in order to control the molar fraction of 3HHx in P(3HB-co-3HHx) produced in the cells. Trace amounts (30μg) of freeze-dried cells were directly subjected to THM-GC in the presence of tetramethylammonium hydroxide (TMAH) at 400°C. The obtained chromatograms clearly showed nine characteristic peaks, attributed to the THM products from 3HB and 3HHx units in the polymer chains, without any appreciable interference by the bacterial matrix components. Based on these peak intensities, the copolymer compositions were determined rapidly without using any cumbersome and lengthy sample pretreatment as in conventional GC method. Moreover, the compositions thus obtained were strongly correlated with those by NMR and conventional GC involving solvent extraction.
    Matched MeSH terms: Chromatography, Gas*
  11. Fulltext Preparation and thermal behaviour of acrylonitrile (an)/ethyl acrylate (ea) copolymer and acrylonitrile (an)/ethyl acrylate (ea)/fumaronitrile (fn) terpolymer as precursors for carbon fibre
    Siti Nurul Ain Md. Jamil, Rusil Daik, Ishak Ahmad
    Pertanika Journal of Science & Technology, 2010;18(2):-.
    MyJurnal
    Redox polymerization of acrylonitrile (AN) with ethyl acrylate (EA) and fumaronitrile (FN), as comonomer and termonomer respectively, were carried out using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiators at 40°C. The actual composition of monomers in copolymers and terpolymers has been characterized by gas chromatography (GC). The effects of EA and FN on the glass transition temperature (Tg) and stabilization temperature have been studied by Differential Scanning Calorimetry (DSC). The degradation behaviour and char yield were obtained by thermogravimetric analysis. Meanwhile, incorporation of 10 mol% of EA in homoPAN system was found to greatly reduce Tg to 66°C as compared to that of the homoPAN (Tg=105°C). The initial cyclization temperature (Ti) was found to be higher (264°C) in comparison to that of homoPAN (246°C). In addition, the incorporation of EA was also shown to reduce the char yield of copolymer to 40%. When FN was incorporated as termonomer, the char yield of poly(AN/EA/ FN) 90/4/6 increased up to 44% after the heat treatment with the lowest Ti (241°C).
    Matched MeSH terms: Chromatography, Gas
  12. Application of statistical experimental methodology to optimize bioremediation of n-alkanes in aquatic environment
    Zahed MA, Aziz HA, Mohajeri L, Mohajeri S, Kutty SR, Isa MH
    J Hazard Mater, 2010 Dec 15;184(1-3):350-6.
    PMID: 20837377 DOI: 10.1016/j.jhazmat.2010.08.043
    Response surface methodology (RSM) was employed to optimize nitrogen and phosphorus concentrations for removal of n-alkanes from crude oil contaminated seawater samples in batch reactors. Erlenmeyer flasks were used as bioreactors; each containing 250 mL dispersed crude oil contaminated seawater, indigenous acclimatized microorganism and different amounts of nitrogen and phosphorus based on central composite design (CCD). Samples were extracted and analyzed according to US-EPA protocols using a gas chromatograph. During 28 days of bioremediation, a maximum of 95% total aliphatic hydrocarbons removal was observed. The obtained Model F-value of 267.73 and probability F<0.0001 implied the model was significant. Numerical condition optimization via a quadratic model, predicted 98% n-alkanes removal for a 20-day laboratory bioremediation trial using nitrogen and phosphorus concentrations of 13.62 and 1.39 mg/L, respectively. In actual experiments, 95% removal was observed under these conditions.
    Matched MeSH terms: Chromatography, Gas
  13. Evaluation of direct transesterification of microalgae using microwave irradiation
    Teo CL, Idris A
    Bioresour Technol, 2014 Dec;174:281-6.
    PMID: 25463809 DOI: 10.1016/j.biortech.2014.10.035
    Nannochloropsis sp. wet biomass was directly transesterified under microwave (MW) irradiation in the presence of methanol and various alkali and acid catalyst. Two different types of direct transesterification (DT) were used; one step and two step transesterification. The biodiesel yield obtained from the MWDT was compared with that obtained using conventional method (lipid extraction followed by transesterification) and water bath heating DT method. Findings revealed that MWDT efficiencies were higher compared to water bath heating DT by at least 14.34% and can achieve a maximum of 43.37% with proper selection of catalysts. The use of combined catalyst (NaOH and H2SO4) increased the yield obtained by 2.3-folds (water bath heating DT) and 2.87-folds (MWDT) compared with the one step single alkaline catalyst respectively. The property of biodiesel produced by MWDT has high lubricating property, good cetane number and short carbon chain FAME's compared with water bath heating DT.
    Matched MeSH terms: Chromatography, Gas
  14. Enhancing the various solvent extraction method via microwave irradiation for extraction of lipids from marine microalgae in biodiesel production
    Teo CL, Idris A
    Bioresour Technol, 2014 Nov;171:477-81.
    PMID: 25201293 DOI: 10.1016/j.biortech.2014.08.024
    The types of microalgae strains and the method used in lipid extraction have become crucial factors which influence the productivity of crude oil. In this paper, Nannochloropsis sp. and Tetraselmis sp. were chosen as the strains and four different methods were used to extract the lipids: Hara and Radin, Folch, Chen and Bligh and Dyer. These methods were performed by using conventional heating and microwave irradiation methods. Results revealed that highest lipid yield from the different species was obtained using different extraction methods; both under microwave irradiation. The lipid yield for Tetraselmis sp. and Nannochloropsis sp. was highest when Hara and Radin (8.19%), and Folch (8.47%) methods were used respectively under microwave irradiation. The lipids extracted were then transesterified to biodiesel and the quality of the biodiesel was analyzed using the gas chromatography.
    Matched MeSH terms: Chromatography, Gas
  15. Recent developments and applications of liquid phase microextraction in fruits and vegetables analysis
    Abdulra'uf LB, Sirhan AY, Huat Tan G
    J Sep Sci, 2012 Dec;35(24):3540-53.
    PMID: 23225719 DOI: 10.1002/jssc.201200427
    The sample preparation step has been identified as the bottleneck of analytical methodology in chemical analysis. Therefore, there is need for the development of cost-effective, easy to operate, and environmentally friendly miniaturized sample preparation technique. The microextraction techniques combine extraction, isolation, concentration, and introduction of analytes into analytical instrument, to a single and uninterrupted step, and improve sample throughput. The use of liquid-phase microextraction techniques for the analysis of pesticide residues in fruits and vegetables are discussed with the focus on the methodologies employed by different researchers and their analytical performances. Analytes are extracted using water-immiscible solvents and are desorbed into gas chromatography, liquid chromatography, or capillary electrophoresis for identification and quantitation.
    Matched MeSH terms: Chromatography, Gas
  16. Fulltext Surface Energy Mapping of Modified Silica Using IGC Technique at Finite Dilution
    Ngeow YW, Williams DR, Chapman AV, Heng JYY
    ACS Omega, 2020 May 12;5(18):10266-10275.
    PMID: 32426583 DOI: 10.1021/acsomega.9b03920
    The reinforcing silica filler, which can be more than 40% of an elastomer composite, plays a key role to achieve the desired mechanical properties in elastomer vulcanizates. However, the highly hydrophilic nature of silica surface causes silica particle aggregation. It remained a challenge for many tire manufacturers when using silica-filled elastomer compounds. Here, the silica surface energy changes when the surface is modified with coupling or noncoupling silanes; coupling silanes can covalently bond the silica to the elastomers. The surface energy of silica was determined using inverse gas chromatography (IGC) at finite dilution (FD-IGC) and found to be reduced by up to 50% when the silica surface was silanized. The spatial distribution of silica aggregates within the tire matrix is determined by transmission electron microscopy (TEM) and a direct correlation between aggregate size (silica microdispersion) and work of cohesion from IGC is reported, highlighting surface energy and work of cohesion being excellent indicators of the degree of dispersion of silica aggregates.
    Matched MeSH terms: Chromatography, Gas
  17. Application of supercritical fluid chromatography in the quantitative analysis of minor components (carotenes, vitamin E, sterols, and squalene) from palm oil
    Choo YM, Ng MH, Ma AN, Chuah CH, Hashim MA
    Lipids, 2005 Apr;40(4):429-32.
    PMID: 16028723
    The application of supercritical fluid chromatography (SFC) coupled with a UV variable-wavelength detector to isolate the minor components (carotenes, vitamin E, sterols, and squalene) in crude palm oil (CPO) and the residual oil from palm-pressed fiber is reported. SFC is a good technique for the isolation and analysis of these compounds from the sources mentioned. The carotenes, vitamin E, sterols, and squalene were isolated in less than 20 min. The individual vitamin E isomers present in palm oil were also isolated into their respective components, alpha-tocopherol, alpha-tocotrienol, gamma-tocopherol, gamma-tocotrienol, and delta-tocotrienol. Calibration of all the minor components of palm as well as the individual components of palm vitamin E was carried out and was found to be comparable to those analyzed by other established analytical methods.
    Matched MeSH terms: Chromatography, Gas
  18. Fulltext Microwave-Assisted Brine Extraction for Enhancement of the Quantity and Quality of Lipid Production from Microalgae Nannochloropsis sp
    Zghaibi N, Omar R, Kamal SMM, Biak DRA, Harun R
    Molecules, 2019 Oct 04;24(19).
    PMID: 31590304 DOI: 10.3390/molecules24193581
    Toward attaining a sustainability and eco-friendly process, a green and low-cost solvent-brine (NaCl solution) is proposed, as microwave-assisted extraction (MAE) technique solvent to extract lipids from microalgae Nannochloropsis sp. The effect of NaCl concentration on the quantity and quality of the extracted lipid was assessed, while MAE parameters were optimized using response surface methodology (RSM). The content of fatty acid methyl esters (FAMEs) in the lipid was analyzed by using a gas chromatography-flame ionization detector (GC/FID). The highest lipid yield (16.1%) was obtained using 10% (w/v) brine at optimum extraction parameters of 5% (w/v) solid loading, 100 °C, and 30 min. The lipid extraction yield via optimized MAE-brine technique was thrice better than that Soxhlet extraction did and only 2% less than Bligh and Dyer (B&D) lipid extraction, which utilized harmful solvents. The proposed MAE-brine technique offered better quality lipids containing the highest amount of polyunsaturated fatty acids (PUFA) (44.5%) and omega-3 fatty acids (FAs) (43%). Hence, the MAE-brine solvent technique appears to be a promising extraction method for cheaper, greener, and faster extraction of a high-quality lipid for specialty food applications.
    Matched MeSH terms: Chromatography, Gas
  19. Preparation of Medicinal Plants: Basic Extraction and Fractionation Procedures for Experimental Purposes
    Abubakar AR, Haque M
    J Pharm Bioallied Sci, 2020 01 29;12(1):1-10.
    PMID: 32801594 DOI: 10.4103/jpbs.JPBS_175_19
    Preparation of medicinal plants for experimental purposes is an initial step and key in achieving quality research outcome. It involves extraction and determination of quality and quantity of bioactive constituents before proceeding with the intended biological testing. The primary objective of this study was to evaluate various methods used in the preparation and screening of medicinal plants in our daily research. Although the extracts, bioactive fractions, or compounds obtained from medicinal plants are used for different purposes, the techniques involved in producing them are generally the same irrespective of the intended biological testing. The major stages included in acquiring quality bioactive molecule are the selection of an appropriate solvent, extraction methods, phytochemical screening procedures, fractionation methods, and identification techniques. The nitty-gritty of these methods and the exact road map followed solely depends on the research design. Solvents commonly used in extraction of medicinal plants are polar solvent (e.g., water, alcohols), intermediate polar (e.g., acetone, dichloromethane), and nonpolar (e.g., n-hexane, ether, chloroform). In general, extraction procedures include maceration, digestion, decoction, infusion, percolation, Soxhlet extraction, superficial extraction, ultrasound-assisted, and microwave-assisted extractions. Fractionation and purification of phytochemical substances are achieved through application of various chromatographic techniques such as paper chromatography, thin-layer chromatography, gas chromatography, and high-performance liquid chromatography. Finally, compounds obtained are characterized using diverse identification techniques such as mass spectroscopy, infrared spectroscopy, ultraviolet spectroscopy, and nuclear magnetic resonance spectroscopy. Subsequently, different methods described above can be grouped and discussed according to the intended biological testing to guide young researchers and make them more focused.
    Matched MeSH terms: Chromatography, Gas
  20. Utilization of waste crab shell (Scylla serrata) as a catalyst in palm olein transesterification
    Boey PL, Maniam GP, Hamid SA
    J Oleo Sci, 2009;58(10):499-502.
    PMID: 19745576
    Aquaculture activity has increased the population of crab, hence increasing the generation of related wastes, particularly the shell. In addition, the number of molting process in crabs compounds further the amount of waste shell generated. As such, in the present work, the application of the waste crab shell as a source of CaO in transesterification of palm olein to biodiesel (methyl ester) was investigated. Preliminary XRD results revealed that thermally activated crab shell contains mainly CaO. Parametric study has been investigated and optimal conditions were found to be methanol/oil mass ratio, 0.5:1; catalyst amount, 4 wt. %; and reaction temperature, 338 K. As compared to laboratory CaO, the catalyst from waste crab shell performs well, thus creating another low-cost catalyst source for producing biodiesel as well as adding value to the waste crab shell. Reusability of crab shell CaO has also been studied and the outcome confirmed that the catalyst is capable to be reutilized up to 11 times, without any major deterioration.
    Matched MeSH terms: Chromatography, Gas
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links