Displaying publications 21 - 40 of 108 in total

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  1. Fulltext A novel aqueous two phase system composed of a thermo-separating polymer and an organic solvent for purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel
    Amid M, Manap Y, Zohdi NK
    Molecules, 2014 May 22;19(5):6635-50.
    PMID: 24858097 DOI: 10.3390/molecules19056635
    The purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel for the first time was investigated using a novel aqueous two-phase system (ATPS) consisting of a thermo-separating copolymer and an organic solvent. The effectiveness of different parameters such as molecular weight of the thermo-separating ethylene oxide-propylene oxide (EOPO) copolymer and type and concentration of organic solvent on the partitioning behavior of amylase was investigated. In addition, the effects of phase components, volume ratio (VR), pH and crude load of purification factor and yield of amylase were evaluated to achieve the optimum partition conditions of the enzyme. In the novel ATPS method, the enzyme was satisfactorily partitioned into the polymer-rich top phase in the system composed of 30% (w/w) EOPO 2500 and 15% (w/w) 2-propanol, at a volume ratio of 1.94 and with a crude load scale of 25% (w/w) at pH 5.0. Recovery and recycling of components was also measured in each successive step of the ATPS process. The enzyme was successfully recovered by the method with a high purification factor of 14.3 and yield of 96.6% and copolymer was also recovered and recycled at a rate above 97%, making the method was more economical than the traditional ATPS method.
    Matched MeSH terms: Chemical Fractionation/methods*
  2. 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: Chemical Fractionation/methods*
  3. Recovery and purification of intracellular polyhydroxyalkanoates from recombinant Cupriavidus necator using water and ethanol
    Mohammadi M, Hassan MA, Phang LY, Ariffin H, Shirai Y, Ando Y
    Biotechnol Lett, 2012 Feb;34(2):253-9.
    PMID: 22038551 DOI: 10.1007/s10529-011-0783-5
    A new halogen-free and environmental-friendly method using water and ethanol is developed as an alternative for the recovery of polyhydroxyalkanoates (PHA) from recombinant Cupriavidus necator in comparison to the established chloroform extraction method. After optimisation, our results showed that the halogen-free method produced a PHA with 81% purity and 96% recovery yield, in comparison to the chloroform extraction system which resulted in a highly pure PHA with 95% yield. Although the purity of the PHA using the new method is lower, the molecular weight of the extracted PHA is not compromised. This new method can be further developed as an alternative and more environmental-friendly method for industrial application.
    Matched MeSH terms: Chemical Fractionation/methods
  4. Comparison of HS-SDME with SPME and SPE for the determination of eight organochlorine and organophosphorus pesticide residues in food matrices
    Kin CM, Huat TG
    J Chromatogr Sci, 2009 Sep;47(8):694-9.
    PMID: 19772747
    A headspace single-drop microextraction (HS-SDME) procedure is optimized for the analysis of organochlorine and organophosphorous pesticide residues in food matrices, namely cucumbers and strawberries by gas chromatography with an electron capture detector. The parameters affecting the HS-SDME performance, such as selection of the extraction solvent, solvent drop volume, extraction time, temperature, stirring rate, and ionic strength, were studied and optimized. Extraction was achieved by exposing 1.5 microL toluene drop to the headspace of a 5 mL aqueous solution in a 15-mL vial and stirred at 800 rpm. The analytical parameters, such as linearity, correlation coefficients, precision, limits of detection (LOD), limits of quantification (LOQ), and recovery, were compared with those obtained from headspace solid-phase microextraction (HS-SPME) and solid-phase extraction. The mean recoveries for all three methods were all above 70% and below 104%. HS-SPME was the best method with the lowest LOD and LOQ values. Overall, the proposed HS-SDME method is acceptable in the analysis of pesticide residues in food matrices.
    Matched MeSH terms: Chemical Fractionation/methods*
  5. Determination of organochlorine and pyrethroid pesticides in fruit and vegetables using solid phase extraction clean-up cartridges
    Sharif Z, Man YB, Hamid NS, Keat CC
    J Chromatogr A, 2006 Sep 15;1127(1-2):254-61.
    PMID: 16857206
    A method to determine six organochlorine and three pyrethroid pesticides in grape, orange, tomato, carrot and green mustard based on solvent extraction followed by solid phase extraction (SPE) clean-up is described. The pesticides were spiked into the sample prior to analysis, extracted with ethyl acetate, evaporated and reconstituted with a solvent mixture of acetone:n-hexane (3:7). Three different sorbents (Strong Anion Exchanger/Primary Secondary Amine (SAX/PSA), Florisil and C18) were used for the clean-up step. Pesticides were eluted with 5mL of acetone:n-hexane (3:7, v/v) and determined by gas chromatography and electron-capture detection (GC-ECD). SAX/PSA was the sorbent, which provided chromatograms with less interference and the mean recoveries obtained were within 70-120% except for captafol. The captafol recoveries for grape were within acceptable range with C18 clean-up column.
    Matched MeSH terms: Chemical Fractionation/methods
  6. Characterization of partitioning behaviors of immunoglobulin G in polymer-salt aqueous two-phase systems
    Chow YH, Yap YJ, Show PL, Juan JC, Anuar MS, Ng EP, et al.
    J Biosci Bioeng, 2016 Nov;122(5):613-619.
    PMID: 27233672 DOI: 10.1016/j.jbiosc.2016.04.008
    The partitioning behavior of immunoglobulin G (IgG) in the aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and phosphate was studied. The parameters of ATPS exhibiting the pronounced effects on the partitioning behavior of IgG include phase composition, PEG molecular weight, and the addition of sodium chloride (NaCl). The accumulation of IgG at the interface of the ATPS increased drastically as the tie-line length (TLL) was increased. This trend was correlated with a linear relationship relating the natural logarithm of interfacial partition coefficient (ln G) to the difference of PEG concentration between the top phase and the bottom phase (Δ[PEG]), and a good fit was obtained. An attempt was made to correlate the natural logarithm of partition coefficient (ln K) to the presence of NaCl with the proposed linear relationship, ln K = α″ ln [Cl(-)] + β″. The proposed relationship, which serves as a better description of the underlying mechanics of the protein partitioning behavior in the polymer-salt ATPS, provides a good fit (r(2) > 0.95) for the data of IgG partitioning. An optimum recovery of 99.97% was achieved in an ATPS (pH 7.5) composed of 14.0% (w/w) PEG 1450, 12.5% (w/w) phosphate and 5.0% (w/w) NaCl.
    Matched MeSH terms: Chemical Fractionation/methods*
  7. Optimization of Protein Extraction and Two-Dimensional Electrophoresis Protocols for Oil Palm Leaf
    Daim LD, Ooi TE, Yusof HM, Majid NA, Karsani SA
    Protein J, 2015 Aug;34(4):304-12.
    PMID: 26263918 DOI: 10.1007/s10930-015-9626-x
    Oil palm (Elaeis guineensis) is an important economic crop cultivated for its nutritional palm oil. A significant amount of effort has been undertaken to understand oil palm growth and physiology at the molecular level, particularly in genomics and transcriptomics. Recently, proteomics studies have begun to garner interest. However, this effort is impeded by technical challenges. Plant sample preparation for proteomics analysis is plagued with technical challenges due to the presence of polysaccharides, secondary metabolites and other interfering compounds. Although protein extraction methods for plant tissues exist, none work universally on all sample types. Therefore, this study aims to compare and optimize different protein extraction protocols for use with two-dimensional gel electrophoresis of young and mature leaves from the oil palm. Four protein extraction methods were evaluated: phenol-guanidine isothiocyanate, trichloroacetic acid-acetone precipitation, sucrose and trichloroacetic acid-acetone-phenol. Of these four protocols, the trichloroacetic acid-acetone-phenol method was found to give the highest resolution and most reproducible gel. The results from this study can be used in sample preparations of oil palm tissue for proteomics work.
    Matched MeSH terms: Chemical Fractionation/methods*
  8. Method validation and determination of heavy metals in cocoa beans and cocoa products by microwave assisted digestion technique with inductively coupled plasma mass spectrometry
    Mohamed R, Zainudin BH, Yaakob AS
    Food Chem, 2020 Jan 15;303:125392.
    PMID: 31446362 DOI: 10.1016/j.foodchem.2019.125392
    In this article, an easy and quick method based on microwave assisted acid digestion technique prior to quantification using inductively coupled plasma mass spectrometry for the analysis of heavy metals in cocoa beans, cocoa powder and chocolate was established and validated for arsenic (As), cadmium (Cd), lead (Pb), and antimony (Sb). Limit of quantification for all elements were product dependent and varies from 7.84 to 194.52 µg/kg. The recoveries of the heavy metals at 250 and 1000 µg/kg spiking levels were ranged between 96.27-108.75%, 90.43-101.97% and 89.72-106.26% for cocoa beans, cocoa powder, and chocolate, respectively. Relative standard deviation values obtained were all below 20% and the expanded uncertainty measurements for the elements were less than 25%. The analysis of real samples found that the concentration level is far from the national alarming level except for cadmium in cocoa beans.
    Matched MeSH terms: Chemical Fractionation/methods*
  9. Sequential ultrasonication and deep eutectic solvent pretreatment to remove lignin and recover xylose from oil palm fronds
    Ong VZ, Wu TY, Lee CBTL, Cheong NWR, Shak KPY
    Ultrason Sonochem, 2019 Nov;58:104598.
    PMID: 31450331 DOI: 10.1016/j.ultsonch.2019.05.015
    This study demonstrated the effect of two-pot sequential pretreatment, comprising of ultrasound assisted deep eutectic solvent (DES) with the aim to investigate the effects of ultrasound amplitude and duration in enhancing delignification. Oil palm fronds (OPF) were ultrasonicated in a water medium, followed by a pretreatment using DES (choline chloride:urea). Fourier transform infra-red spectroscopy, X-ray diffraction, field emission scanning electron microscope, Brunauer-Emmet-Teller and solubilised lignin concentration were conducted to confirm the effectiveness of ultrasound assisted DES on the pretreatment of OPF. The recommended ultrasound conditions were determined to be 70% amplitude and duration of 30 min, where the sequential DES pretreatment was able to reduce lignin content of OPF to 14.01%, while improving xylose recovery by 58%.
    Matched MeSH terms: Chemical Fractionation/methods*
  10. GC-MS analysis of metabolites from soxhlet extraction, ultrasound-assisted extraction and supercritical fluid extraction of Salacca zalacca flesh and its alpha-glucosidase inhibitory activity
    Saleh MSM, Bukhari DAM, Siddiqui MJA, Kasmuri AR, Murugesu S, Khatib A
    Nat Prod Res, 2020 May;34(9):1341-1344.
    PMID: 30678487 DOI: 10.1080/14786419.2018.1560295
    Different extraction processes were employed to extract bioactive metabolites from Salacca zalacca flesh by a range of aqueous and organic solvents. The highest extraction yield was obtained by 50% ethanol extract of SE (73.18 ± 4.35%), whereas SFE_1 showed the lowest yield (0.42 ± 0.08%). All extracts were evaluated for in vitro α-glucosidase inhibitory activity, measured by their IC50 values in comparison to that of quercetin, the positive control (IC50 = 2.7 ± 0.7 μg/mL). The lowest α-glucosidase inhibitory activity was indicated by water extract of SE (IC50 = 724.3 ± 42.9 μg/mL) and the highest activity was demonstrated by 60% ethanol extract by UAE (IC50 = 16.2 ± 2.4 μg/mL). All extracts were analysed by GC-MS and identified metabolites like carbohydrates, fatty acids, organic acids, phenolic acids, sterols and alkane-based compounds etcetera that may possess the potential as α-glucosidase inhibitor and may attribute to the α-glucosidase inhibitory activity.
    Matched MeSH terms: Chemical Fractionation/methods*
  11. Egg white lysozyme purification by a stirred cell contactor equipped with a weak ion-exchange nanofiber membrane: Process development and scale-up
    Lee SY, Liu BL, Wu JY, Chang YK
    Food Chem, 2021 Feb 15;338:128144.
    PMID: 33092004 DOI: 10.1016/j.foodchem.2020.128144
    A weak ion-exchange membrane (P-COOH) was synthesized by alkaline hydrolysis of a polyacrylonitrile nanofiber membrane prepared by electrospinning process. The P-COOH membrane was characterized for its physical properties and its application for purification of lysozyme from chicken egg white was investigated. The lysozyme adsorption efficiency of the P-COOH membrane operating in a stirred cell contactor (Millipore, Model 8010) was evaluated. The effects of key parameters such as the feed concentration, the rotating speed, the flow rate of feed and the operating pressure were studied. The results showed successful purification of lysozyme with a high recovery yield of 98% and a purification factor of 63 in a single step. The purification strategy was scaled-up to the higher feedstock loading volume of 32.7 and 70 mL using stirred cell contactors of Model 8050 and 8200, respectively. The scale-up processes achieved similar purification results, proving linear scalability of the purification technique adopted.
    Matched MeSH terms: Chemical Fractionation/instrumentation*
  12. A combined microwave pretreatment/solvent extraction process for the production of oil from palm fruit: optimisation, oil quality and effect of prolonged exposure
    Tan JC, Chuah CH, Cheng SF
    J Sci Food Agric, 2017 Apr;97(6):1784-1789.
    PMID: 27470073 DOI: 10.1002/jsfa.7975
    BACKGROUND: Conventional palm oil milling involves multiple stages after fruit collection; in particular, oil clarification introduces water into the pressed oil, which results in a large quantity of wastewater.

    RESULTS: A combined process of microwave pretreatment and solvent extraction to mill crude palm oil, without introducing water or steam, is described. An excellent yield (up to 30%) of oil was obtained with pretreatment in a 42 L, 1000 W and 2450 MHz microwave oven followed by hexane extraction. The optimum conditions (10 min microwave pretreatment and 12 h solvent extraction) yielded an oil with a low free fatty acid content (<1.0%) and an acceptable anisidine value (<3.0 meq kg(-1) ). The oil had a fatty acid composition not resembling those of conventional crude palm oil and crude palm kernel oil. In the pretreatment, the leached oil had 6.3% lauric acid whereas the solvent extracted oil had only 1.5% lauric acid. Among the factors affecting the oil quality, microwave pretreatment affected the oil quality significantly; however, an optimised duration that would ensure high efficiency in solvent extraction also resulted in ruptured fruitlets, although not to the extent of causing excessive oxidation. In fact, microwave pretreatment should exceed 12 min; after only 15 min, the oil had 1-methylcyclopentanol (12.96%), 1-tetradecanol (9.44%), 1-nonadecene (7.22%), nonanal (7.13%) and 1-tridecene (5.09%), which probably arose from the degradation of fibres.

    CONCLUSION: Microwave pretreatment represents an alternative milling process for crude palm oil compared with conventional processes in the omission of wet treatment with steam. © 2016 Society of Chemical Industry.

    Matched MeSH terms: Chemical Fractionation/methods*
  13. Fulltext Optimization of Flavonoid Extraction from Red and Brown Rice Bran and Evaluation of the Antioxidant Properties
    Ghasemzadeh A, Baghdadi A, Z E Jaafar H, Swamy MK, Megat Wahab PE
    Molecules, 2018 Jul 26;23(8).
    PMID: 30049990 DOI: 10.3390/molecules23081863
    Recently, the quality-by-design concept has been widely implemented in the optimization of pharmaceutical processes to improve batch-to-batch consistency. As flavonoid compounds in pigmented rice bran may provide natural antioxidants, extraction of flavonoid components from red and brown rice bran was optimized using central composite design (CCD) and response surface methodology (RSM). Among the solvents tested, ethanol was most efficient for extracting flavonoids from rice bran. The examined parameters were temperature, solvent percentage, extraction time, and solvent-to-solid ratio. The highest total flavonoid content (TFC) in red rice bran was predicted as 958.14 mg quercetin equivalents (QE)/100 g dry matter (DM) at 58.5 °C, 71.5% (v/v), 36.2 min, and 7.94 mL/g, respectively, whereas the highest TFC in brown rice bran was predicted as 782.52 mg QE/100 g DM at 56.7 °C, 74.4% (v/v), 36.9 min, and 7.18 mL/g, respectively. Verification experiment results under these optimized conditions showed that the TFC values for red and brown rice bran were 962.38 and 788.21 mg QE/100 g DM, respectively. No significant differences were observed between the predicted and experimental TFC values, indicating that the developed models are accurate. Analysis of the extracts showed that apigenin and p-coumaric acid are abundant in red and brown rice bran. Further, red rice bran with its higher flavonoid content exhibited higher nitric oxide and 2,2-diphenyl-1-picrylhydrazyl scavenging activities (EC50 values of 41.3 and 33.6 μg/mL, respectively) than brown rice bran. In this study, an extraction process for flavonoid compounds from red and brown rice bran was successfully optimized. The accuracy of the developed models indicated that the approach is applicable to larger-scale extraction processes.
    Matched MeSH terms: Chemical Fractionation/methods
  14. Cloud-point extraction of green-polymers from Cupriavidus necator lysate using thermoseparating-based aqueous two-phase extraction
    Leong YK, Lan JC, Loh HS, Ling TC, Ooi CW, Show PL
    J Biosci Bioeng, 2017 Mar;123(3):370-375.
    PMID: 27745851 DOI: 10.1016/j.jbiosc.2016.09.007
    Polyhydroxyalkanoates (PHAs), a class of renewable and biodegradable green polymers, have gained attraction as a potential substitute for the conventional plastics due to the increasing concern towards environmental pollution as well as the rapidly depleting petroleum reserve. Nevertheless, the high cost of downstream processing of PHA has been a bottleneck for the wide adoption of PHAs. Among the options of PHAs recovery techniques, aqueous two-phase extraction (ATPE) outshines the others by having the advantages of providing a mild environment for bioseparation, being green and non-toxic, the capability to handle a large operating volume and easily scaled-up. Utilizing unique properties of thermo-responsive polymer which has decreasing solubility in its aqueous solution as the temperature rises, cloud point extraction (CPE) is an ATPE technique that allows its phase-forming component to be recycled and reused. A thorough literature review has shown that this is the first time isolation and recovery of PHAs from Cupriavidus necator H16 via CPE was reported. The optimum condition for PHAs extraction (recovery yield of 94.8% and purification factor of 1.42 fold) was achieved under the conditions of 20 wt/wt % ethylene oxide-propylene oxide (EOPO) with molecular weight of 3900 g/mol and 10 mM of sodium chloride addition at thermoseparating temperature of 60°C with crude feedstock limit of 37.5 wt/wt %. Recycling and reutilization of EOPO 3900 can be done at least twice with satisfying yield and PF. CPE has been demonstrated as an effective technique for the extraction of PHAs from microbial crude culture.
    Matched MeSH terms: Chemical Fractionation/methods*
  15. Recovery of lignin peroxidase from submerged liquid fermentation of Amauroderma rugosum (Blume & T. Nees) Torrend using polyethylene glycol/salt aqueous two-phase system
    Jong WYL, Show PL, Ling TC, Tan YS
    J Biosci Bioeng, 2017 Jul;124(1):91-98.
    PMID: 28319022 DOI: 10.1016/j.jbiosc.2017.02.008
    Amauroderma rugosum is a wild mushroom species widely distributed in tropics and is classified under the class of Basidiomycetes. Basidiomycetes are well-known for their abilities of producing lignocellulolytic enzymes such as lignin peroxidase (LiP), laccase (Lac) and manganese peroxidase (MnP). Different factors such as nutrient sources, incubation period and agitation affect the production of lignocellulolytic enzymes. The A. rugosum produced LiP in the medium supplemented with potato dextrose broth (PDB), 0.5% yeast and 1.0% saw dust at 26.70±3.31 U/mL. However, the LiP activity was increased to 106.32±5.32 U/mL when supplemented with 150 μm of copper (CuSO4). The aqueous two-phase system (ATPS) is a simple, rapid and low cost method for primary extraction and recovery of LiP. A total of 25 systems made from five different molecular weights of polyethylene glycol (PEG)/dipotassium hydrogen phosphate (K2HPO4) were tested. PEG 600 produced the highest top phase purification factor (PFT) of 1.33±0.62 with yield of 72.18±8.50%. The optimization of the ATPS parameters, such as volume ratio VR, pH and crude enzyme loading are the factors controlling the phase partition. Our results showed that significant improvement (PFT of 6.26±2.87 with yield of 87.31±3.14%) of LiP recovery can be achieved by optimized the parameters.
    Matched MeSH terms: Chemical Fractionation/methods*
  16. 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: Chemical Fractionation/methods*
  17. Extraction and physicochemical characterization of chitin and chitosan from Zophobas morio larvae in varying sodium hydroxide concentration
    Soon CY, Tee YB, Tan CH, Rosnita AT, Khalina A
    Int J Biol Macromol, 2018 Mar;108:135-142.
    PMID: 29175166 DOI: 10.1016/j.ijbiomac.2017.11.138
    Large amount of sodium hydroxide (NaOH) is consumed to remove the protein content in chitin biomass during deproteinization. However, excessive NaOH concentration used might lead to the reduction of cost effectiveness during chitin extraction. Hence, the present study aimed to extract and evaluate the physicochemical properties of chitin and chitosan isolated from superworm (Zophobas morio) larvae using 0.5M-2.0M of NaOH. The extracted chitin and chitosan were subjected to Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis, Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD). The 0.5M NaOH treatment resulted in the highest yield of chitin (5.43%), but produced the lowest yield (65.84%) of chitosan. The extracted chitin samples had relatively high degree of acetylation (DA) (82.39%-101.39%). Both chitin and chitosan showed smooth surface with tiny pores. The extracted chitin samples were confirmed as α-chitin based on the FT-IR and TGA. The chitin samples were amorphous with low degree of crystallinity. From TGA, the Chitosan 3 extracted was partially deacetylated. Both DPPH radical scavenging and ferric-chelating assay showed positive correlation with DD of chitosan isolates. However, the chitosan isolates were not fully dissolved, resulting in lower radical scavenging and ferric-chelating ability compared to commercial chitosan.
    Matched MeSH terms: Chemical Fractionation/methods*
  18. A high-performance protocol for extraction of microplastics in fish
    Karami A, Golieskardi A, Choo CK, Romano N, Ho YB, Salamatinia B
    Sci Total Environ, 2017 Feb 01;578:485-494.
    PMID: 27836345 DOI: 10.1016/j.scitotenv.2016.10.213
    So far, several classes of digesting solutions have been employed to extract microplastics (MPs) from biological matrices. However, the performance of digesting solutions across different temperatures has never been systematically investigated. In the first phase of the present study, we measured the efficiency of different oxidative agents (NaClO or H2O2), bases (NaOH or KOH), and acids [HCl or HNO3; concentrated and diluted (5%)] in digesting fish tissues at room temperature (RT, 25°C), 40, 50, or 60°C. In the second phase, the treatments that were efficient in digesting the biological materials (>95%) were evaluated for their compatibility with eight major plastic polymers (assessed through recovery rate, Raman spectroscopy analysis, and morphological changes). Among the tested solutions, NaClO, NaOH, and diluted acids did not result in a satisfactory digestion efficiency at any of the temperatures. The H2O2 treatment at 50°C efficiently digested the biological materials, although it decreased the recovery rate of nylon-6 (NY6) and nylon-66 (NY66) and altered the colour of polyethylene terephthalate (PET) fragments. Similarly, concentrated HCl and HNO3 treatments at RT fully digested the fish tissues, but also fully dissolved NY6 and NY66, and reduced the recovery rate of most or all of the polymers, respectively. Potassium hydroxide solution fully eliminated the biological matrices at all temperatures. However, at 50 and 60°C, it degraded PET, reduced the recovery rate of PET and polyvinyl chloride (PVC), and changed the colour of NY66. According to our results, treating biological materials with a 10% KOH solution and incubating at 40°C was both time and cost-effective, efficient in digesting biological materials, and had no impact on the integrity of the plastic polymers. Furthermore, coupling this treatment with NaI extraction created a promising protocol to isolate MPs from whole fish samples.
    Matched MeSH terms: Chemical Fractionation/methods*
  19. Aqueous two-phase flotation for primary recovery of bacteriocin-like inhibitory substance (BLIS) from Pediococcus acidilactici Kp10
    Md Sidek NL, Tan JS, Abbasiliasi S, Wong FW, Mustafa S, Ariff AB
    J Chromatogr B Analyt Technol Biomed Life Sci, 2016 Aug 01;1027:81-7.
    PMID: 27262666 DOI: 10.1016/j.jchromb.2016.05.024
    An aqueous two-phase flotation (ATPF) system based on polyethylene glycol (PEG) and sodium citrate (NaNO3C6H5O7·2H2O) was considered for primary recovery of bacteriocin-like inhibitory substance (BLIS) from Pediococcus acidilactici Kp10. The effects of ATPF parameters namely phase composition, tie-line length (TLL), volume ratio between the two phases (VR), amount of crude load (CL), pH, nitrogen gas flow rate (FR) and flotation time (FT) on the performance of recovery were evaluated. BLIS was mainly concentrated into the upper PEG-rich phase in all systems tested so far. The optimum conditions for BLIS purification, which composed of PEG 8000/sodium citrate, were: TLL of 42.6, VR of 0.4, CL of 22% (w/w), pH 7, average FT of 30min and FR of 20mL/min. BLIS was partially purified up to 5.9-fold with a separation efficiency of 99% under this optimal conditions. A maximum yield of BLIS activity of about 70.3% was recovered in the PEG phase. The BLIS from the top phase was successfully recovered with a single band in SDS-gel with molecular weight of about 10-15kDa. ATPF was found to be an effective technique for the recovery of BLIS from the fermentation broth of P. acidilactici Kp10.
    Matched MeSH terms: Chemical Fractionation/methods*
  20. A comparative study of physicochemical characteristics and functionalities of pinto bean protein isolate (PBPI) against the soybean protein isolate (SPI) after the extraction optimisation
    Tan ES, Ying-Yuan N, Gan CY
    Food Chem, 2014;152:447-55.
    PMID: 24444960 DOI: 10.1016/j.foodchem.2013.12.008
    Optimisation of protein extraction yield from pinto bean was investigated using response surface methodology. The maximum protein yield of 54.8 mg/g was obtained with the optimal conditions of: temperature=25 °C, time=1 h and buffer-to-sample ratio=20 ml/g. PBPI was found to obtain high amount of essential amino acids such as leucine, lysine, and phenylalanine compared to SPI. The predominant proteins of PBPI were vicilin and phytohemagglutinins whereas the predominant proteins of SPI were glycinin and conglycinins. Significantly higher emulsifying capacity was found in PBPI (84.8%) compared to SPI (61.9%). Different isoelectric points were found in both PBPI (4.0-5.5) and SPI (4.0-5.0). Also, it was found that PBPI obtained a much higher denaturation temperature of 110.2 °C compared to SPI (92.5 °C). Other properties such as structural information, gelling capacity, water- and oil-holding capacities, emulsion stability as well as digestibility were also reported.
    Matched MeSH terms: Chemical Fractionation
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