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1.
Isolation of pectins form flax pedicels and fibers was studied. Isolated pectins and flax fibers treated by various chemical procedures were studied by IR spectroscopy. The morphology of fascicles of flax fibers was studied by electron microscopy as influenced by chemical treatment.  相似文献   

2.
Three industrial pectins, viz., citrus, apple, and beet pectins were examined for the chemical composition, sorption, and electroosmotic transfer. The gelation concentrations, charge, and binding of the pectins to water and heavy metals were determined.  相似文献   

3.
The objective of this study was to characterize the properties of pectin extracted from sugar beet pulp using subcritical water (SWE) as compared to conventional extraction (CE). The research involved advanced modeling using response surface methodology and optimization of operational parameters. The optimal conditions for maximum yield of pectin for SWE and CE methods were determined by the central composite design. The optimum conditions of CE were the temperature of 90 °C, time of 240 min, pH of 1, and pectin recovery yield of 20.8%. The optimal SWE conditions were liquid-to-solid (L/S) ratio of 30% (v/w) at temperature of 130 °C for 20 min, which resulted in a comparable yield of 20.7%. The effect of obtained pectins on viscoamylograph pasting and DSC thermal parameters of corn starch was evaluated. The contents of galacturonic acid, degree of methylation, acetylation, and ferulic acid content were higher in the pectin extracted by SWE, while the molecular weight was lower. Similar chemical groups were characterized by FTIR in both SWE and CE pectins. Color attributes of both pectins were similar. Solutions of pectins at lower concentrations displayed nearly Newtonian behavior. The addition of both pectins to corn starch decreased pasting and DSC gelatinization parameters, but increased ΔH. The results offered a promising scalable approach to convert the beet waste to pectin as a value-added product using SWE with improved pectin properties.  相似文献   

4.
Trends in the science and applications of pectins   总被引:1,自引:0,他引:1  
The literature on the chemistry and application of pectins is reviewed. The principal themes are the search for nontraditional sources of pectins with novel structural elements and the deeper understanding of the structure and physicochemical properties of well studied pectins from traditional sources (apple, beet, citrus). Custom preparation of pectins with a desired set of properties that have practical application in medicine, biology and the food industry has been demonstrated. Chemical modification of pectins is a promising trend.Institute of Polymer Chemistry and Physics, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (998-71)-144-26-61. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–11, January–February, 2000.  相似文献   

5.
Pectins were isolated from bark, wood and pith of kenaf (Hibiscus cannabinus L.) variety Cuba108. Imidazole was used as extractant. The isolated pectins were studied by 13C nuclear magnetic resonance (13C-NMR) spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). From the spectroscopic investigation, the isolated pectic substances were found similar to commercial pectins.  相似文献   

6.
Pectins were isolated from bark, wood and pith of four kenaf (Hibiscus cannabinus L.) varieties. The degree of esterification of isolated pectins was studied using Fourier transform infrared spectroscopy. It was determined as being between 57 and 90% and there were no notable differences between kenaf varieties. The higher value of the degree of esterification was presented in wood pectins (86-90%), the interim in pith (75-83%) and the lower in bark (57-64%).  相似文献   

7.
Pectin solutions obtained in the presence of HNO3, HCl, H2SO4, and H3PO4 have been studied by viscometry, turbidity spectra, and ultracentrifugation. Cotton pectin extracts with phosphoric acid proved to be the most unstable. The molecular masses of pectins obtained from various materials (apple, lemon, and grape press residues, beet pulp, and cotton boll valves) ranged between 14,000 and 37,000. The polydispersity of the pectins isolated was studied.Tashkent State Technical University, fax (3712) 29 48 36. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 349–353, May–June, 1998.  相似文献   

8.
The biological activity of apple pectin extracted conventionally or enzymatically using endo-xylanase and endo-cellulase, was tested in vitro. The analyses were performerd in tetraplicates and the statistical significance of the differences were assessed using ANOVA, Tukey post hoc and LSD (the least significant difference) tests. Multivariate regression analysis was applied to determine the structural components that have a crucial importance for antioxidant and antitumor properties of pectins. The pectins extracted by enzymes contained up to four times more ferulic acid and showed twice as great ability to neutralize free radicals and Fe(III) reduction. The antiradical potential positively correlated with phenols, fucose and rhamnose content. In the assays performed on HT-29 human adenocarcinoma and B16F10 melanoma cell cultures, the “green” pectins, contrary to acid isolated ones, exhibited remarkable anti-neoplastic potential while being nontoxic to nontransformed L929 cell line. The pectins in the dose of 1 mg/mL were capable of inhibiting adhesion (max 23.1%), proliferation (max 40.4%), invasion (max 76.9%) and anchorage-independent growth (max 90%) of HT-29 cells (significance level p < 0.001). These pectin preparations were slightly less active towards B16F10 cells. The enzyme-isolated apple pectins may be useful as a functional food additive and an ingredient of the ointment formulas for post-surgical melanoma treatment.  相似文献   

9.
Abstract

A high-performance gel permeation chromatographic (GPC) method was developed to determine the molecular weight distribution of pectins. The chromatographic system consisted of a hydrophilic coated silica (SynChropak) as the packing and a pH 3.7 acetate buffer as the mobile phase. By use of this system, high-methoxy, low-methoxy, and amidated pectins could be analyzed within fifteen minutes. By determining partition coefficients (Kd) of pectins as a function of mobile phase composition, Kd values were found to be independent of ionic strength from 0.055 to 0.7 M using pH 3.7 acetate buffers, which was in agreement, with intrinsic viscosity data.  相似文献   

10.
A low-cost, automated pyrolysis-mass spectrometer based on a quadrupole mass analyser (Prutec PYMS system) was evaluated by analysing three sample sets (orange juices, pectins and micro-organisms) and by comparison with results obtained on a manual pyrolysis-mass spectrometer based on a magnetic mass analyser (VG Gas Analysis, Pyromass 8–80). Reproducibility of replicate analyses was better on the PYMS system for orange juices and pectins and was comparable with the Pyromass for micro-organisms. Discrimination of samples was always achieved by the PYMS system and, if the data analysis was restricted to m/z 51–140, the PYMS discrimination was superior to that obtained on the Pyromass for orange juices and pectins but was inferior for micro-organisms. The use of a wider mass range in the data analysis on the Pyromass 8–80 improved the discrimination of orange juices and pectins but impaired the discrimination of micro-organisms.  相似文献   

11.
Sulfasalazine (SLZ) is a synthetic nonsteroidal anti-inflammatory drug used mainly for the treatment of an inflammatory bowel and other diseases. Two pectins with different methylation degrees were blended to synthesized gel microspheres by ionotropic gelation for SLZ encapsulation. The encapsulation efficiency was found to be around of 99% in all formulations tested. However, different SLZ release profiles related to the methylation degrees of pectin were observed. Mixture of low methylated (LM) and high methylated (HM) pectins in the presence of calcium(II) displayed the best microsphere morphologies among the formulations tested determined by optical and electronic microscopies. The percentage of drug release using a mixture of LM and HM pectins after 255?min in simulated gastric fluid (pH?=?1.2), simulated intestinal fluid (pH?=?6.8), and phosphate buffer (pH?=?7.4) were 15.0%, 47.0%, and 52.2%, respectively.  相似文献   

12.
Summary 1. The protopectins of the petioles and leaves of Sosnovskii's cowparsnip and heartleaf colewort have been studied. It has been shown that the protopectins of wild-growing herbs are similar to the pectins of fruit and vegetables.2. The heterogeneity of the pectins isolated has been shown by the fractionation method. Two main fractions were obtained — neutral (weakly acidic) and acidic.M. V. Lomonosov Odessa Technological Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 760–763, November–December, 1977.  相似文献   

13.
Some molecular and structural features of apple pectins obtained by various methods have been revealed through an analysis of the results of physical and physicochemical investigations.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 792–796, November–December, 1997.  相似文献   

14.
Conditions of manufacture of microcrystalline cellulose from variously treated short flax fibers and of powdered cellulose from flax straw were examined. The effect of fats, waxes, and pectins contained in the fibers on the kinetics of hydrolysis of the polysaccharide was studied.  相似文献   

15.
Russian Journal of General Chemistry - Low- and high-methoxylated pectins were synthesized and modified with anthranilic and salicylic acids to obtain effective polymeric ligands. On their basis,...  相似文献   

16.
The aim of this study was to isolate pectins with antioxidant activity from the leaves of Epilobium angustifolium L. Two pectins, EA-4.0 and EA-0.8, with galacturonic acid contents of 88 and 91% were isolated from the leaves of E. angustifolium L. by the treatment of plant raw materials with aqueous hydrochloric acid at pH 4.0 and 0.8, respectively. EA-4.0 and EA-0.8 were found to scavenge the DPPH radical in a concentration-dependent manner at 17–133 μg/mL, whereas commercial apple pectin scavenged at 0.5–2 mg/mL. The antioxidant activity of EA-4.0 was the highest and exceeded the activity of EA-0.8 and a commercial apple pectin by 2 and 39 times (IC50—0.050, 0.109 and 1.961 mg/mL), respectively. Pectins EA-4.0 and EA-0.8 were found to possess superoxide radical scavenging activity, with IC50s equal to 0.27 and 0.97 mg/mL, respectively. Correlation analysis of the composition and activity of 32 polysaccharide fractions obtained by enzyme hydrolysis and anionic exchange chromatography revealed that the antioxidant capacity of fireweed pectins is mainly due to phenolics and is partially associated with xylogalacturonan chains. The data obtained demonstrate that pectic polysaccharides appeared to be bioactive components of fireweed leaves with high antioxidant activity, which depend on pH at their extraction.  相似文献   

17.
A series of water-soluble derivatives of natural and synthetic polysaccharides (dextran, pectins, Phycoll, pullulan, hydroxyethyl starch) containing aldehyde, hydrazide, sulfonate, and hydrazine groups were prepared.  相似文献   

18.
An HS-SPME GC-MS analysis of the volatile compounds adsorbed at the outer surface of lemon and grapefruit pectins obtained via the hydrodynamic cavitation of industrial waste streams of lemon and grapefruit peels in water suggests important new findings en route to understanding the powerful and broad biological activity of these new pectic materials. In agreement with the ultralow degree of esterification of these pectins, the high amount of highly bioactive α-terpineol and terpinen-4-ol points to limonene (and linalool) decomposition catalyzed by residual citric acid in the citrus waste peel residue of the juice industrial production.  相似文献   

19.
Pectins are dietary fibers with different structural characteristics. Specific pectin structures can influence the gastrointestinal immune barrier by directly interacting with immune cells or by impacting the intestinal microbiota. The impact of pectin strongly depends on the specific structural characteristics of pectin; for example, the degree of methyl-esterification, acetylation and rhamnogalacturonan I or rhamnogalacturonan II neutral side chains. Here, we review the interactions of specific pectin structures with the gastrointestinal immune barrier. The effects of pectin include strengthening the mucus layer, enhancing epithelial integrity, and activating or inhibiting dendritic cell and macrophage responses. The direct interaction of pectins with the gastrointestinal immune barrier may be governed through pattern recognition receptors, such as Toll-like receptors 2 and 4 or Galectin-3. In addition, specific pectins can stimulate the diversity and abundance of beneficial microbial communities. Furthermore, the gastrointestinal immune barrier may be enhanced by short-chain fatty acids. Moreover, pectins can enhance the intestinal immune barrier by favoring the adhesion of commensal bacteria and inhibiting the adhesion of pathogens to epithelial cells. Current data illustrate that pectin may be a powerful dietary fiber to manage and prevent several inflammatory conditions, but additional human studies with pectin molecules with well-defined structures are urgently needed.Subject terms: Mucosal immunology, Translational immunology  相似文献   

20.
Following the analysis of terpenes present in new lemon and grapefruit “IntegroPectin” pectins obtained via the hydrodynamic cavitation of industrial lemon and grapefruit processing waste, the HPLC-MS analysis of flavonoid and other phenolic compounds reveals the presence of eriocitrin, naringin, hesperidin and kaempferol typical of the respective citrus fruits. The pectic fibers rich in rhamnogalacturonan-I regions act as chemical sponges adsorbing and concentrating at their outer surface highly bioactive citrus flavonoids and terpenes. These findings, together with the unique molecular structure of these new whole citrus pectins, provide preliminary insight into the broad-scope biological activity of these new biomaterials. Numerous new biomedical applications are anticipated, including likely use in the prevention and treatment of microbial infections and neurodegenerative disease.  相似文献   

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