Displaying publications 21 - 40 of 84 in total

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  1. Fulltext Extraction and characterization of pectin from grapefruit (Duncan cultivar) and its utilization as gelling agent
    Khan, A. A., Butt, M.S., Randhawa, M.A., Karim, R., Sultan, M.T., Ahmed, W.
    International Food Research Journal, 2014;21(6):2195-2199.
    MyJurnal
    Globally, agro-industrial by products such as fruit waste has attained immense recognition to be used for the extraction of valuable functional ingredients. Pectin is naturally occurring biopolymer that is widely recognized in food industry as well as in biotechnology. Keeping in view, current research was conducted for extraction, characterization and utilization of grapefruit peel pectin from Duncan cultivar. The extracted pectin was characterized for different parameters that explored its role in value added products. Acid extraction was carried out and then pectin was characterized for equivalent weight, ash content and methoxyl content. With the addition of extracted pectin, jam was prepared and analysed for physicochemical analysis and sensory attributes. The maximum extraction (22.55%) was done from grapefruit peel at temperature-120°C with pH-1.5, while minimum extraction (0.41%) was obtained at temperature-120°C with pH-2. Moreover, adding pectin in jam formulation resulted in significant effect on texture of the final product. Conclusively, pectin holds a great potential to be extracted and utilized in fruit based products for best quality and value addition.
    Matched MeSH terms: Pectins
  2. Fulltext Microwave-assisted extraction of pectin from jackfruit rinds using different power levels
    Koh, P.C., Leong, C.M., Noranizan, M.A.
    International Food Research Journal, 2014;21(5):2091-2097.
    MyJurnal
    Pectin is a heterogeneous branched polysaccharide with complex structure. Microwave-assisted
    extraction (MAE) is more efficient in extracting pectin compared to conventional method. The objective of this study was to compare the efficiency of microwave-assisted pectin extraction against conventional extraction method. This study was also to investigate the effect of power level on yield and quality of extracted pectin from jackfruit rinds. Water-based extraction method was performed with the extraction duration for conventional extraction and MAE were 1 h and 10 min, respectively. The temperature of conventional extraction was set at 90°C and the power levels of MAE were 450 W, 600 W and 800 W. High yield of pectin was obtained from conventional extraction (14.59%) and MAE (16.72-17.63%). All quality characteristics determined were found to be insignificant different for pectin extracted from both conventional extraction and MAE except moisture and ash content. Increase in microwave power did not affect yield and quality characteristics of pectin from jackfruit rinds significantly. In conclusion, MAE requires shorter time than conventional extraction in extracting comparable amount and quality of pectin from jackfruit rinds. Microwave-assisted extraction at 450 W was the most effective and economic extraction condition among the different power levels tested.
    Matched MeSH terms: Pectins
  3. Fulltext Optimization studies on microwave assisted extraction of dragon fruit (Hylocereus polyrhizus) peel pectin using response surface methodology
    Rahmati, S., Abdullah, A., Momeny, E., Kang, O.L.
    International Food Research Journal, 2015;22(1):233-239.
    MyJurnal
    Optimization of microwave assisted extraction of dragon fruit peel pectin was conducted using respond surface methodology. Effect of extraction conditions, i.e. pH value (X1), extraction time (X2) and solid-liquid ratio (X3) on the extraction yield was investigated using a central composite experimental design. Optimization of microwave assisted extraction was performed and three-dimensional (3D) response surface plots were derived from the mathematical models. Analysis of variance (ANOVA) was conducted and indicated a significant interaction between extraction conditions (pH value and extraction time) and extraction yield. The optimum conditions of microwave assisted extraction were as follows: X1 = 2.07; X2 = 65 s and X3 = 66.57. The verification test on pectin extraction was performed and revealed a perfect agreement between experimental and predicted values. The maximum predicted yield of pectin extraction was 18.53%. Overall, application of microwave assisted extraction can give rise to high quality dragon fruit peel pectin.
    Matched MeSH terms: Pectins
  4. Extraction and characterization of Pectin from Dragon fruit (Hylocereus polyrhizus) using various extraction conditions
    Norazelina Sah Mohd Ismail, Nazaruddin Ramli, Norziah Mohd Hani, Zainudin Meon
    Sains Malaysiana, 2012;41:41-45.
    The extraction of pectin from dragon fruit (Hylocereus polyrhizus) peels under three different extraction conditions was identified as an alternative source of commercial pectin. In this work, dried alcohol-insoluble residues (AIR) of dragon fruit peels were treated separately with 0.25% ammonium oxalate/oxalic acid at a pH of 4.6 at 85oC; 0.03 M HCl at a pH of 1.5 at 85oC; and de-ionized water at 75oC. The pectin obtained from these methods was compared in terms of yield, physicochemical properties and chemical structure. Fourier Transform Infrared Spectroscopy (FTIR) was used in the identification of dragon fruit pectins. The results showed that the pectin yield (14.96-20.14% based on dry weight), moisture content (11.13-11.33%), ash content (6.88-11.55%), equivalent weight (475.64-713.99), methoxyl content (2.98-4.34%), anhydrouronic acid (45.25-52.45%) and the degree of esterification (31.05-46.96%) varied significantly (p < 0.05) with the various extraction conditions used. Pectin extracted with ammonium oxalate gave the highest yield of pectin, with high purity and low ash content. Based on the value of methoxyl content and the degree of esterification, dragon fruit pectin can be categorized as low-methoxyl pectin.
    Matched MeSH terms: Pectins
  5. 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: Pectins/isolation & purification*; Pectins/chemistry*
  6. Deep eutectic solvents (DES) mediated extraction of pectin from Averrhoa bilimbi: Optimization and characterization studies
    Shafie MH, Yusof R, Gan CY
    Carbohydr Polym, 2019 Jul 15;216:303-311.
    PMID: 31047070 DOI: 10.1016/j.carbpol.2019.04.007
    The Box-Behnken design was applied to optimize the extraction of pectin from Averrhoa bilimbi (ABP) using deep eutectic solvents (DES). The four variables of extraction were percentage of DES (X1), extraction time (X2), temperature (X3), and molar ratio of DES components (X4). The quadratic regression equation was established as a predicted model with R2 value of 0.9375. The optimal condition was X1 = 3.74% (w/v), X2 = 2.5 h, X3 = 80 °C, and X4 = 1:1. No significant difference between the predicted (14.70%) and experimental (14.44%) maximum yield of sample was noted. Characterization of physico-chemical properties characterization of ABP was performed. The main components of ABP were galacturonic acids, arabinoses, and xyloses. ABP also showed good functional properties such as water holding capacity (3.70 g/g), oil holding capacity (2.40 g/g), and foaming capacity (133.33%). The results also showed that ABP exhibited free radical scavenging activity (41.46%) and ferric reducing antioxidant power (1.15 mM).
    Matched MeSH terms: Pectins/isolation & purification; Pectins/chemistry*
  7. Hylocereus polyrhizus peel's high-methoxyl pectin: A potential source of hypolipidemic agent
    Zaid RM, Mishra P, Wahid ZA, Sakinah AMM
    Int J Biol Macromol, 2019 Aug 01;134:361-367.
    PMID: 31059740 DOI: 10.1016/j.ijbiomac.2019.03.143
    In the present study, high-methoxyl pectin (HMP) was extracted from Hylocereus polyrhizus peel's using physico-chemical process. In addition, the hypolipidemic activity of HMP was investigated at different concentration and time corresponding to its adsorption ability. FTIR and contact angle analysis were used to determine the sorbent characterization. A high degree of esterification (63.8%) and the contact angle (95.5°) confirmed hydrophobic nature and resulting bad wetting of the HMP extract, respectively. The methoxyl content in the pectin acted as an affinity-precursor of the pectin towards cholesterol due to its increased hydrophobicity. The maximum equilibrium uptake capacity of cholesterol of 370.5mg/g (0.96mmol/g) was observed by HMP. The experimental data showed good fitting for Freundlich isotherm equation and followed pseudo-first-order kinetic model with a correlation coefficient (R2) of 0.89-0.97 due to physisorption mechanism. Intra-particle model confirmed that the cholesterol sorption rate by HMP was significantly influenced by external mass transfer (surface diffusion) and intra-particle diffusion (diffusion control). It was also revealed that the HMP extracted from Hylocereus polyrhizus peels possess a high affinity towards cholesterol, making it an ideal hypolipidemic agent.
    Matched MeSH terms: Pectins/pharmacology*; Pectins/chemistry*
  8. Optimization of Pectin Extraction from Sweet Potato Peels Using Citric Acid and its Emulsifying Properties
    Hamidon NH, Abang Zaidel DN, Mohd Jusoh YM
    Recent Pat Food Nutr Agric, 2020;11(3):202-210.
    PMID: 32031081 DOI: 10.2174/2212798411666200207102051
    BACKGROUND: Pectin is a natural polysaccharide that has been used widely as a stabilizer in food emulsion system.

    OBJECTIVE: This study aimed to optimize the yield of pectin extracted from sweet potato residue and investigate its emulsifying properties.

    METHODS: Response surface methodology (RSM) has been utilized to investigate the pectin extracted from sweet potato peels using citric acid as the extracting solvent. Investigation of the effect of different extraction conditions namely temperature (°C), time (min) and solution pH on pectin yield (%) were conducted. A Box-Benhken design with three levels of variation was used to optimize the extraction conditions.

    RESULTS: The optimal conditions determined were temperature 76°C, time 64 min and pH 1.2 with 65.2% yield of pectin. The degree of esterification (DE) of the sweet potato pectin was determined using Fourier Transform Infrared (FTIR) Spectroscopy. The pectin is high-methoxyl pectin with DE of 58.5%. Emulsifying properties of sweet potato pectin were investigated by measuring the zeta-potential, particle size and creaming index with addition of 0.4 and 1.0 wt % pectin to the emulsion.

    CONCLUSION: Extraction using citric acid could improve the pectin yield. Improved emulsion stability was observed with the addition of the sweet potato pectin.

    Matched MeSH terms: Pectins/isolation & purification*; Pectins/chemistry*
  9. Could choline chloride-citric acid monohydrate molar ratio in deep eutectic solvent affect structural, functional and antioxidant properties of pectin?
    Shafie MH, Gan CY
    Int J Biol Macromol, 2020 Apr 15;149:835-843.
    PMID: 32027904 DOI: 10.1016/j.ijbiomac.2020.02.013
    The deep eutectic solvents (DESs), which were made from different molar ratios (3:1, 2:1, 1:1, 1:2, 1:3) of choline chloride and citric acid monohydrate, were used as media for the pectic polysaccharide extraction from Averrhoa bilmbi (ABP). The physico-chemical, structural, functional and antioxidant properties of ABP were subsequently determined. The ABP was found to be xylogalacturonan. Moreover, results showed that different structures (i.e. linearity of pectin and branch size) of ABP were obtained, hence, affecting the solubility and functional properties due to the surface availability and steric effect. In addition, when increasing the molar ratio of citric acid monohydrate in DES, lower pH and higher TPC values were observed. These values were correlated with antioxidant activities (i.e. free radical scavenging activity and ferric reducing antioxidant power) of ABP. In conclusion, the molar ratio of the DES components plays an important role in extracting ABP with the aforementioned properties.
    Matched MeSH terms: Pectins/pharmacology*; Pectins/chemistry*
  10. Microwave modified non-crosslinked pectin films with modulated drug release
    Anuar NK, Wong TW, Taib MN
    Pharm Dev Technol, 2012 Jan-Feb;17(1):110-7.
    PMID: 20958167 DOI: 10.3109/10837450.2010.522584
    The effects of microwave on drug release properties of pectin films carrying sulfanilamide (SN-P), sulfathiazole (ST-P) and sulfamerazine (SM-P) of high to low aqueous solubilities were investigated. These films were prepared by solvent evaporation technique and treated by microwave at 80 W for 5-40 min. Their profiles of drug dissolution, drug content, matrix interaction and matrix crystallinity were determined by drug dissolution testing, drug content assay, differential scanning calorimetry, X-ray diffractometry and scanning electron microscopy techniques. Microwave induced an increase in matrix amorphousness but lower drug release propensity with a greater retardation extent in SN-P films, following a rise in strength of matrix interaction. A gain in amorphous structure does not necessarily increase the drug release of film. Microwave can possibly retard drug release of pectin film carrying water-soluble drug through modulating its state of matrix interaction.
    Matched MeSH terms: Pectins/radiation effects*; Pectins/chemistry*
  11. Drug release property of chitosan-pectinate beads and its changes under the influence of microwave
    Wong TW, Nurjaya S
    Eur J Pharm Biopharm, 2008 May;69(1):176-88.
    PMID: 17980563
    The effects of microwave irradiation on the drug release property of pectinate beads loaded internally with chitosan (chitosan-pectinate beads) were investigated against the pectinate beads and beads coacervated with chitosan externally (pectinate-chitosonium beads). These beads were prepared by an extrusion method using sodium diclofenac as the model water-soluble drug. The beads were subjected to microwave irradiation at 80 W for 5, 10, 21 and 40 min. The profiles of drug dissolution, drug content, drug-polymer interaction and polymer-polymer interaction were determined by drug dissolution testing, drug content assay, drug adsorption study, differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR) techniques. Treatment of pectinate beads by microwave did not lead to a decrease, but an increase in the extent of drug released at 4h of dissolution owing to reduced pectin-pectin interaction via the CO moiety of polymer. In addition, the extent of drug released from the pectinate beads could not be reduced merely through the coacervation of pectinate matrix with chitosan. The reduction in the extent of drug released from the pectinate-chitosonium beads required the treatment of these beads by microwave, following an increase in drug-polymer and polymer-polymer interaction in the matrix. The extent of drug released from the pectinate beads was reduced through incorporating chitosan directly into the interior of pectinate matrix, owing to drug-chitosan adsorption. Nonetheless, the treatment of chitosan-pectinate matrix by microwave brought about an increase in the extent of drug released unlike those of pectinate-chitosonium beads. Apparently, the loading of chitosan into the interior of pectinate matrix could effectively retard the drug release without subjecting the beads to the treatment of microwave. The microwave was merely essential to reduce the release of drug from pectinate beads when the chitosan was introduced to the pectinate matrix by means of coacervation. Under the influences of microwave, the drug release property of beads made of pectin and chitosan was mainly modulated via the CH, OH and NH moieties of polymers and drug, with CH functional group purported to retard while OH and NH moieties purported to enhance the drug released from the matrix.
    Matched MeSH terms: Pectins/radiation effects; Pectins/chemistry*
  12. Fulltext Design of polysaccharidic nano-in-micro soft agglomerates as primary oral drug delivery vehicle for colon-specific targeting
    Musa N, Wong TW
    Carbohydr Polym, 2020 Nov 01;247:116673.
    PMID: 32829801 DOI: 10.1016/j.carbpol.2020.116673
    Microencapsulation of polysaccharidic nanoparticles is met with nanoscale and biological performance changes. This study designs soft agglomerates as nanoparticle vehicle without nanoparticles undergoing physical processes that alter their geometry. The nanoparticles were made of high molecular weight chitosan/pectin with covalent 5-fluorouracil/folate. Nanoparticle aggregation vehicle was prepared from low molecular weight chitosan. The nanoparticles and aggregation vehicle were blended in specific weight ratios to produce soft agglomerates. Nanoparticles alone are unable to agglomerate. Adding aggregation vehicle (< 2 μm) promoted soft agglomeration with nanoparticles deposited onto its surfaces with minimal binary coalescence. The large and rough-surfaced aggregation vehicle promoted nanoparticles deposition and agglomeration. A rounder vehicle allowed assembly of nanoparticles-on-aggregation vehicle into agglomerates through interspersing smaller between larger populations. Soft agglomeration reduced early drug release, and was responsive to intracapsular sodium alginate coat to further sustain drug release. The soft agglomerates can serve as a primary oral colon-specific vehicle.
    Matched MeSH terms: Pectins
  13. Physico-chemical characteristics of red pitaya (Hylocereus polyrhizus) peel
    Jamilah, B., Shu, C. E., Kharidah, M., Dzulkifly, M. A., Noranizan, A.
    International Food Research Journal, 2011;18(1):279-286.
    MyJurnal
    Pitaya peel (Hylocereus polyrhizus), which consists approximately 22% of the whole fruit weight, is discarded during processing. Physico-chemical properties of the discarded pitaya peel were determined in
    order to evaluate its potential for recovery of any value-added materials. The moisture content of the peel was approximately 92.7% and it was low in total soluble solids, protein, ash and fat content. Betacyanin pigment (150.46 ± 2.19 mg/100 g) and pectin (10.8%) were high in the peel. Glucose, maltose and fructose were detected in the peel but not sucrose and galactose. The peel also had very high insoluble and soluble dietary fibre which had exhibited a good ratio of insoluble dietary fibre to soluble dietary fibre (3.8: 1.0).
    Matched MeSH terms: Pectins
  14. Fulltext Rheological properties of native and modified corn starches in the presence of hydrocolloids
    Shaari, N.A., Sulaiman, R., Cheok, C.Y.
    International Food Research Journal, 2017;24(5):2082-2089.
    MyJurnal
    Starch and hydrocolloids were often used together in food industry to modify the rheological properties with the aim to enhance the starch tolerance to processing conditions. As such, the rheological properties of xanthan gum (XG), carrageenan, high (HMP) and low methoxyl pectin (LMP), with native corn starch (NCS) and modified corn starch (MCS) at different temperature were evaluated in this study. The flow behavior index (n) of corn starch-hydrocolloid mixtures were observed in the range from 0.160 to 0.604 where indicated the shear thinning behavior. The addition of hydrocolloids increased the apparent viscosity of the starch system. NCS mixtures showed consistency index (K) and apparent viscosities (na,100) decreased with increase in the temperature. The addition of XG and carrageenan increased the storage (G’) and loss (G”) moduli. Among the hydrocolloids, the XG addition to the NCS exhibited superior viscoelastic properties as evidenced by the highest G’ and lowest tan δ values. XG was observed capable to increase while pectin reduced the solid-like starch system. This result provides pragmatic data for food engineer in process design and food product development by minimizing the cost of trial and error.
    Matched MeSH terms: Pectins
  15. Fulltext Characterization of CRISPR Mutants Targeting Genes Modulating Pectin Degradation in Ripening Tomato
    Wang D, Samsulrizal NH, Yan C, Allcock NS, Craigon J, Blanco-Ulate B, et al.
    Plant Physiol, 2019 02;179(2):544-557.
    PMID: 30459263 DOI: 10.1104/pp.18.01187
    Tomato (Solanum lycopersicum) is a globally important crop with an economic value in the tens of billions of dollars, and a significant supplier of essential vitamins, minerals, and phytochemicals in the human diet. Shelf life is a key quality trait related to alterations in cuticle properties and remodeling of the fruit cell walls. Studies with transgenic tomato plants undertaken over the last 20 years have indicated that a range of pectin-degrading enzymes are involved in cell wall remodeling. These studies usually involved silencing of only a single gene and it has proved difficult to compare the effects of silencing these genes across the different experimental systems. Here we report the generation of CRISPR-based mutants in the ripening-related genes encoding the pectin-degrading enzymes pectate lyase (PL), polygalacturonase 2a (PG2a), and β-galactanase (TBG4). Comparison of the physiochemical properties of the fruits from a range of PL, PG2a, and TBG4 CRISPR lines demonstrated that only mutations in PL resulted in firmer fruits, although mutations in PG2a and TBG4 influenced fruit color and weight. Pectin localization, distribution, and solubility in the pericarp cells of the CRISPR mutant fruits were investigated using the monoclonal antibody probes LM19 to deesterified homogalacturonan, INRA-RU1 to rhamnogalacturonan I, LM5 to β-1,4-galactan, and LM6 to arabinan epitopes, respectively. The data indicate that PL, PG2a, and TBG4 act on separate cell wall domains and the importance of cellulose microfibril-associated pectin is reflected in its increased occurrence in the different mutant lines.
    Matched MeSH terms: Pectins/genetics; Pectins/immunology; Pectins/metabolism*
  16. Development and physicochemical characterization of alginate composite film loaded with simvastatin as a potential wound dressing
    Rezvanian M, Amin MCIM, Ng SF
    Carbohydr Polym, 2016 Feb 10;137:295-304.
    PMID: 26686133 DOI: 10.1016/j.carbpol.2015.10.091
    Previously, studies have demonstrated that topical application of simvastatin can promote wound healing in diabetic mice via augmentation of angiogenesis and lymphangiogenesis. This study aimed to formulate and characterize simvastatin in alginate-based composite film wound dressings. Biopolymers used for composite films were sodium alginate blended with pectin or gelatin. The films were prepared and characterized based on their physical properties, surface morphology, mechanical strength and rheology. Then, in vitro drug releases from the films were investigated and, finally, the cell viability assay was performed to assess the cytotoxicity profile. From the pre-formulation studies, alginate/pectin composite film showed to possess desirable wound dressing properties and superior mechanical properties. The in vitro drug release profile revealed that alginate/pectin film produced a controlled release drug profile, and cell viability assay showed that the film was non-toxic. In summary, alginate/pectin composite film is suitable to be formulated with simvastatin as a potential wound dressing.
    Matched MeSH terms: Pectins/chemistry
  17. Comparison of alginate and pectin based beads for production of poultry probiotic cells
    Voo WP, Ravindra P, Tey BT, Chan ES
    J Biosci Bioeng, 2011 Mar;111(3):294-9.
    PMID: 21216192 DOI: 10.1016/j.jbiosc.2010.11.010
    A comparative study on the stability and potential of alginate and pectin based beads for production of poultry probiotic cells using MRS medium in repeated batch fermentation was conducted. The bead cores, made of three types of materials, i.e., ca-alginate, ca-pectinate and ca-alginate/pectinate, were compared. The effect of single and double layer coatings using chitosan and core material, respectively, on the bead stability and cell production were also studied. The pectin based beads were found to be more stable than that of the alginate beads and their stability was further improved by coating with chitosan. The cell concentration in pectin based beads was comparable to that in the alginate beads. On the other hand, pectin based beads gave significantly lower cell concentration in the growth medium for the initial fermentation cycles when compared to the alginate beads. In conclusion, pectin was found to be potential encapsulation material for probiotic cell production owing to its stability and favourable microenvironment for cell growth.
    Matched MeSH terms: Pectins/chemistry*
  18. Analysis and optimization of flocculation activity and turbidity reduction in kaolin suspension using pectin as a biopolymer flocculant
    Ho YC, Norli I, Alkarkhi AF, Morad N
    Water Sci Technol, 2009;60(3):771-81.
    PMID: 19657173 DOI: 10.2166/wst.2009.303
    The performance of pectin in turbidity reduction and the optimum condition were determined using Response Surface Methodology (RSM). The effect of pH, cation's concentration, and pectin's dosage on flocculating activity and turbidity reduction was investigated at three levels and optimized by using Box-Behnken Design (BBD). Coagulation and flocculation process were assessed with a standard jar test procedure with rapid and slow mixing of a kaolin suspension (aluminium silicate), at 150 rpm and 30 rpm, respectively, in which a cation e.g. Al(3+), acts as coagulant, and pectin acts as the flocculant. In this research, all factors exhibited significant effect on flocculating activity and turbidity reduction. The experimental data and model predictions well agreed. From the 3D response surface graph, maximum flocculating activity and turbidity reduction are in the region of pH greater than 3, cation concentration greater than 0.5 mM, and pectin dosage greater than 20 mg/L, using synthetic turbid wastewater within the range. The flocculating activity for pectin and turbidity reduction in wastewater is at 99%.
    Matched MeSH terms: Pectins/chemistry*
  19. Removal of chromium ions from aqueous solutions by polymer-enhanced ultrafiltration
    Aroua MK, Zuki FM, Sulaiman NM
    J Hazard Mater, 2007 Aug 25;147(3):752-8.
    PMID: 17339078
    This study deals with the removal of chromium species from aqueous dilute solutions using polymer-enhanced ultrafiltration (PEUF) process. Three water soluble polymers, namely chitosan, polyethyleneimine (PEI) and pectin were selected for this study. The ultrafiltration studies were carried out using a laboratory scale ultrafiltration system equipped with 500,000 MWCO polysulfone hollow fiber membrane. The effects of pH and polymer composition on rejection coefficient and permeate flux at constant pressure have been investigated. For Cr(III), high rejections approaching 100% were obtained at pH higher than 7 for the three tested polymers. With chitosan and pectin, Cr(VI) retention showed a slight increase with solution pH and did not exceed a value of 50%. An interesting result was obtained with PEI. The retention of Cr(VI) approached 100% at low pH and decreased when the pH was increased. This behavior is opposite to what one can expect in the polymer-enhanced ultrafiltration of heavy metals. Furthermore, the concentration of polymer was found to have little effect on rejection. Permeate flux remained almost constant around 25% of pure water flux.
    Matched MeSH terms: Pectins/chemistry
  20. Purification and properties of a beta-galactosidase from carambola fruit with significant activity towards cell wall polysaccharides
    Balasubramaniam S, Lee HC, Lazan H, Othman R, Ali ZM
    Phytochemistry, 2005 Jan;66(2):153-63.
    PMID: 15652572
    beta-Galactosidase (EC. 3.2.1.23) from ripe carambola (Averrhoa carambola L. cv. B10) fruit was fractionated through a combination of ion exchange and gel filtration chromatography into four isoforms, viz. beta-galactosidase I, II, III and IV. This beta-galactosidases had apparent native molecular masses of 84, 77, 58 and 130 kDa, respectively. beta-Galactosidase I, the predominant isoform, was purified to electrophoretic homogeneity; analysis of the protein by SDS-PAGE revealed two subunits with molecular masses of 48 and 36 kDa. N-terminal amino acid sequence of the respective polypeptides shared high similarities albeit at different domains, with the deduced amino acid sequence of certain plant beta-galactosidases, thus, explaining the observed low similarity between the two subunits. beta-Galactosidase I was probably a heterodimer that have glycoprotein properties and a pI value of 7.2, with one of the potential glycosylation sites appeared to reside within the 48-kDa-polypeptide. The purified beta-galactosidase I was substantially active in hydrolyzing (1-->4)beta-linked spruce and a mixture of (1-->3)beta- and (1-->6)beta-linked gum arabic galactans. This isoform also had the capability to solubilize and depolymerize structurally intact pectins as well as to modify alkaline-soluble hemicelluloses, reflecting in part changes that occur during ripening.
    Matched MeSH terms: Pectins/metabolism
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