19 results on '"Abelmoschus"'
Search Results
2. Structural characterization and anti-inflammatory activity of a polysaccharide from the lignified okra
- Author
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Yong Liu, Xiaobo Hu, Yun-Fang Ye, and Jun-Hui Wang
- Subjects
Arabinose ,Magnetic Resonance Spectroscopy ,Polymers and Plastics ,Rhamnose ,medicine.drug_class ,Cell Survival ,Anti-Inflammatory Agents ,02 engineering and technology ,010402 general chemistry ,Polysaccharide ,Nitric Oxide ,01 natural sciences ,Anti-inflammatory ,chemistry.chemical_compound ,Mice ,Abelmoschus ,Polysaccharides ,Materials Chemistry ,medicine ,Animals ,Ethanol precipitation ,chemistry.chemical_classification ,integumentary system ,biology ,Chemistry ,Hexuronic Acids ,fungi ,Organic Chemistry ,NF-kappa B ,Galactose ,021001 nanoscience & nanotechnology ,biology.organism_classification ,0104 chemical sciences ,Molecular Weight ,RAW 264.7 Cells ,Biochemistry ,Phosphorylation ,Cytokines ,0210 nano-technology - Abstract
The polysaccharide (AP1-b) of molecular weight 6.59 × 105 Da was isolated from lignified okra (Abelmoschus esculentus (L.) Moench) by hot-water extraction, 40 % ethanol precipitation and purified by DEAE Cellulose chromatography, respectively. The structure and anti-inflammatory activity of AP1-b were investigated. AP1-b was composed of galactose, rhamnose, gluctose, arabinose and galacturonic acid in a molar ratio of 1.98:1.00:0.15:0.32:0.29. The structural features showed that the AP1-b consisted of →2)-α- d -Rhap-(1→, →4)-β- d -Galp-(1→, →4)-α- d -GalpA-(1→, →6)-β- d -Galp-(1→, β- d -Glcp-(1→ and α- l -Araf-(1→. AP1-b could observably improve the inflammatory injury of LPS-induced RAW 264.7 cells by inhibiting the secretion of NO and decreasing the levels of pro-inflammatory factors (IL-1β, iNOS and TNF-α). AP1-b also inhibited the phosphorylation levels of IκB and p65 proteins, manifesting the anti-inflammatory activity of AP1-b may associated with inhibition of NF-κB signaling pathway. Therefore, AP1-b had potential value in treating inflammatory injury.
- Published
- 2020
3. Fine structure, physicochemical and antioxidant properties of LM-pectins from okra pods dried under different techniques
- Author
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Mario M. Martinez, Mengmeng Guo, Kang Xu, and Bin Yang
- Subjects
food.ingredient ,Antioxidant ,Hot Temperature ,Polymers and Plastics ,Pectin ,DPPH ,medicine.medical_treatment ,Emulsifying properties ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Antioxidants ,chemistry.chemical_compound ,food ,Antioxidant activity ,Picrates ,Abelmoschus ,Materials Chemistry ,Side chain ,medicine ,Food science ,Benzothiazoles ,Desiccation ,Microwaves ,Drying ,ABTS ,Aqueous solution ,Organic Chemistry ,Biphenyl Compounds ,Galactan ,Apparent viscosity ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Freeze Drying ,chemistry ,Fruit ,Sunlight ,Pectins ,Sulfonic Acids ,0210 nano-technology ,Rheology - Abstract
This work investigates the effect of drying okra pods by different techniques [freeze-drying (FD), sun-drying (SD), oven-drying (OD) and microwave-drying (MD)] on the molecular structure, physicochemical and antioxidant properties of the subsequently extracted OP. Remarkably, although the degree of methyl esterification (∼41.1 %) remained similar among samples, the content of galacturonic acid (62.67–68.77 %), average number molecular weight (MnI: 758.8–808.5 kDa, MnII: 20.9–24.2 kDa), and to a greater extent the apparent viscosity of an aqueous solution of pectin molecules, water holding capacity (0.21–10.71 g/g) and emulsifying activity (42.3–72.7 %) and stability (38.6–53.5 %), decreased with the drying temperature in the order of FD-OP > SD-OP > OD-OP > MD-OP. On the other hand, only FD-OP presented a higher proportion of galactan and/or arabinan side chains [(Ara + Gal) / Rha = 12.37%] compared to the rest of the samples, with values ranging from 7.79 to 9.17%. FD-OP and SD-OP resulted in lower DPPH and ABTS radical scavenging activities.
- Published
- 2019
4. Investigating the influence of pectin content and structure on its functionality in bio-flocculant extracted from okra
- Author
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Eleanor Binner, Stephen E. Harding, Rachael Millett, Yujie Mao, Gleb E. Yakubov, and Chai Siah Lee
- Subjects
chemistry.chemical_classification ,Flocculation ,food.ingredient ,Polymers and Plastics ,Pectin ,Plant Extracts ,Organic Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Polysaccharide ,01 natural sciences ,0104 chemical sciences ,Water Purification ,food ,Linear relationship ,chemistry ,Abelmoschus ,Okra extract ,Materials Chemistry ,Pectins ,Food science ,0210 nano-technology ,Polymer bridging - Abstract
Okra extract is known to have potential application as a bio-flocculant for wastewater treatment. However, no research to date has given insight into the components responsible for the flocculating ability of okra extract or its flocculating mechanism. The work presented here addresses this knowledge gap showing that pectin, especially pectin homogalacturonan (HGA) regions, appear to be the polysaccharides responsible for the flocculating ability of okra extract. The way pectin works in flocculation may be best explained by a polymer bridging mechanism. Specifically, a linear relationship between okra bio-flocculating ability and pectin homogalacturonan region to rhamnogalacturonan-I region weight ratio (HGA/RG-I) was found (y = 2.0x+47.6, R2 = 0.93, when GalA content > 300 mg/g extract), which was also validated using commercial citrus peel pectin.
- Published
- 2019
5. Extraction and characterization of polysaccharides from tamarind seeds, rice mill residue, okra waste and sugarcane bagasse for its Bio-thermoplastic properties
- Author
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V. Renuka, M. Sukumar, B Vajiha Aafrin, C. Chandra Mohan, U. Lalitha priya, K. Harini, P Maria Jenita, K Sudarshan, S. Karthikeyan, and S. Babuskin
- Subjects
Polymers and Plastics ,Starch ,02 engineering and technology ,010402 general chemistry ,Polysaccharide ,01 natural sciences ,chemistry.chemical_compound ,Crystallinity ,Abelmoschus ,Polysaccharides ,Amylose ,Tamarindus ,Materials Chemistry ,Food science ,Cellulose ,chemistry.chemical_classification ,Bran ,Chemistry ,Organic Chemistry ,food and beverages ,Oryza ,021001 nanoscience & nanotechnology ,Saccharum ,0104 chemical sciences ,Mucilage ,Seeds ,0210 nano-technology ,Bagasse - Abstract
The aim of the present study is to extract potential thermoplastic polysaccharides from agricultural industrial wastes. Polysaccharides were extracted from renewable agro industrial wastes such as tamarind seeds [rich in starch (TSS)], okra head waste [rich in mucilage polysaccharide (OMP)], sugarcane bagasse [rich in cellulose (SBC)] and residual rice mill wastes [rich in starch and fiber (RS)]. Urigam variety of tamarind seed starch found to be an amylose rich starch. Different polysaccharides extracted from agro wastes were found to be having high thermal stability, except okra polysaccharide (comparatively low). X-ray diffraction pattern of tamarind seed starch proved its high crystallinity index. Crystallinity index of investigated polysaccharides were found to be in the order of SBC > TSS > RS > OMP. Chemical nature of extracted polysaccharides was confirmed by Fourier transform infrared spectroscopic analysis. Residual rice bran starch granules and tamarind seed starch globules were found to be having comparatively reduced particle size than sugarcane bagasse cellulose and okra mucilage. Scanning electron microscopic analysis revealed the cluster formations of RS granules and TSS globules. Residual rice bran starch found to be associated with other fibers (present in outer coat of rice). Okra mucilage and SBC were examined to be having linear sheets and linear bundles structures, respectively.
- Published
- 2018
6. Nanocomposite films based on CMC, okra mucilage and ZnO nanoparticles: Physico mechanical and antibacterial properties
- Author
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Abolfazl Kamkar, Ali Misaghi, and Hamid Reza Sadegh Mohammadi
- Subjects
Staphylococcus aureus ,Materials science ,Morphology (linguistics) ,Chemical Phenomena ,Polymers and Plastics ,Surface Properties ,Color ,Microbial Sensitivity Tests ,02 engineering and technology ,Permeability ,Nanocomposites ,Plant Mucilage ,0404 agricultural biotechnology ,Abelmoschus ,Polysaccharides ,Tensile Strength ,Ultimate tensile strength ,Escherichia coli ,Materials Chemistry ,Organic chemistry ,Solubility ,Nanocomposite ,Organic Chemistry ,Water ,04 agricultural and veterinary sciences ,021001 nanoscience & nanotechnology ,Microstructure ,040401 food science ,Anti-Bacterial Agents ,Steam ,Chemical engineering ,Mucilage ,Nanoparticles ,Zinc Oxide ,Elongation ,0210 nano-technology ,Antibacterial activity - Abstract
This work examined the physico mechanical parameters and antibacterial activity of CMC/okra mucilage (OM) blend films containing ZnO nanoparticles (NPs). Different proportions of CMC and okra mucilage (100/0; 70/30; 60/40 and 50/50 respectively), were mixed and casted to posterior analysis of formed films. The more colored films were obtained by higher contents of okra mucilage and adding ZnO nanoparticles. The incorporation of ZnO NPs into CMC film decreased the elongation at the break (EB) value of the films and increased the tensile strength (TS) value of the film. With increase in CMC concentration in the films, higher water vapor permeability and higher solubility in water were achieved. Microstructure analysis using SEM showed a smooth and compact surface morphology, homogeneous structure, and a rough surface for CMC, CMC+ZnO, and CMC/OM30%+ZnO, respectively. Nanocomposite films presented antibacterial activity against tested bacteria. Films contained okra mucilage showed more antibacterial activity. The inhibitory activities of resultant films were stronger against S. aureus than E. coli.
- Published
- 2018
7. Fabrication and characterization of a novel konjac glucomannan-based air filtration aerogels strengthened by wheat straw and okara
- Author
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Saffa Riffat, Fatang Jiang, Ying Fang, Weiling Wang, Xuewen Ni, Kao Wu, Yixin Wang, and Su, Yuehong
- Subjects
Materials science ,food.ingredient ,Polymers and Plastics ,Starch ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Gelatin ,law.invention ,Contact angle ,Mannans ,chemistry.chemical_compound ,food ,law ,Abelmoschus ,Air permeability specific surface ,Materials Chemistry ,Filtration ,Triticum ,Mechanical Phenomena ,Organic Chemistry ,Aerogel ,Microporous material ,Straw ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Air Filters ,0210 nano-technology ,Gels ,Porosity - Abstract
The konjac glucomannan (KGM)-based aerogel as an air filtration material was fabricated through sol-gel and freeze-drying methods. Results showed that gelatin and starch addition could increase the filtration efficiency and compressive strength of aerogel significantly, due to the appearance of more microporous structure and the formation of dense structure in aerogel. The addition of wheat straw could decrease the filtration resistance and increase the breathability of KGM-based aerogel, which was attributed to the multi-cavities of wheat straw. The aerogel with wheat straw had a filtration efficiency of 93.54% for particle matters ≥ 0.3 μm, a filtration resistance 29 Pa, and an air permeability 271.42 L/s·m2. Okara addition could increase the hydrophobicity of KGM-based aerogel by increasing the water contact angle and decreasing the equilibrium water content. The water contact angle of the aerogel containing okara reached 105.4°, and the equilibrium water content was decreased by 17.03%–81.10% compared with that without okara, with relative humidity 0%–80%. The results demonstrated that the KGM-based aerogel had good performance on filtration, mechanical and hydrophobic properties, indicating high potential application as an air filtration material.
- Published
- 2019
8. Grafting modification of okra mucilage: Recent findings, applications, and future directions
- Author
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Jae-Jin Shim, Jintae Lee, and Vinit Raj
- Subjects
Biocompatible polymers ,Polymers and Plastics ,Computer science ,Grafting (decision trees) ,Liquid-Liquid Extraction ,Antineoplastic Agents ,Chemistry Techniques, Synthetic ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Antioxidants ,Water Purification ,Plant Mucilage ,Drug Delivery Systems ,Anti-Infective Agents ,Abelmoschus ,Materials Chemistry ,Food Industry ,Humans ,Hypoglycemic Agents ,Organic Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Carbohydrate Sequence ,Mucilage ,Biochemical engineering ,0210 nano-technology - Abstract
Okra polysaccharides are biocompatible polymers with antimicrobial, anticancer, hypoglycemic, and antioxidant characteristics and hence are used in different fields such as drug delivery, food industry, and wastewater treatment. Consequently, okra-polymer modification by different methods, such as grafting, to satisfy industrial demands is attracting much scientific attention. Although a large body of literature is available on the extraction of okra polysaccharides and their applications, little is known about their grafting modification. While crosslinking and binary grafting can help in the realization of the desired properties, these methods have not been widely used on okra polysaccharides. In this review, we highlight the different methods used for the extraction of okra polysaccharides and systematically summarize major findings on their grafting modification and applications in different industries. This information will help in designing experimental protocols for the modification of okra polysaccharides to suit future needs.
- Published
- 2020
9. Effects of simulated saliva-gastrointestinal digestion on the physicochemical properties and bioactivities of okra polysaccharides
- Author
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Shengpeng Wang, Li Zhao, Tao Gou, Yuan He, Pan-Yin Xiang, Qin Yuan, Ding-Tao Wu, Ren-You Gan, Wen Qin, Miao-Miao Shen, and Zheng-Wen Cao
- Subjects
Saliva ,Antioxidant ,Polymers and Plastics ,medicine.medical_treatment ,02 engineering and technology ,010402 general chemistry ,Polysaccharide ,01 natural sciences ,Gastrointestinal digestion ,Abelmoschus ,Polysaccharides ,Materials Chemistry ,medicine ,Humans ,Food science ,chemistry.chemical_classification ,Molecular mass ,Plant Extracts ,Chemistry ,Prebiotic ,Stomach ,Organic Chemistry ,Glycosidic bond ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Prebiotics ,Digestion ,0210 nano-technology - Abstract
This study was to investigate the effects of in vitro simulated saliva-gastrointestinal digestion on the physicochemical properties and bioactivities of okra polysaccharides (OPS). Results showed that the digestibilities of OPS were about 5.1%, 37.5%, and 41.3% after saliva digestion (SD), saliva-gastric digestion (SGD), and saliva-gastrointestinal digestion (SGID), respectively. The SGID significantly changed the physicochemical properties of OPS, such as total uronic acids, total flavonoids, monosaccharide composition, rheological properties, and molecular weights (Mw). Especially, Mw changes resulted in the breakdown of glycosidic bonds during SGD, and the degradation of OPS during SGID was mainly caused by disrupting aggregates. Furthermore, the bioactivities of OPS were also affected by SGID. After SGID, OPS still possessed strong antioxidant activities, binding capacities, and prebiotic activities, but the α-glucosidase inhibitory effect was obviously decreased. Overall, results can provide valuable and scientific support on the oral administration of OPS as functional foods and medicines in the future.
- Published
- 2020
10. Colorimetric film based on polyvinyl alcohol/okra mucilage polysaccharide incorporated with rose anthocyanins for shrimp freshness monitoring
- Author
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Minmin Chen, Shaotong Jiang, Xingjiang Li, Junfeng Cheng, Shaolei Kang, Li Xia, Linlin Li, and Hualin Wang
- Subjects
Food Safety ,Polymers and Plastics ,Active packaging ,Composite film ,02 engineering and technology ,Rosa ,010402 general chemistry ,High sensitive ,complex mixtures ,01 natural sciences ,Polyvinyl alcohol ,Anthocyanins ,chemistry.chemical_compound ,Penaeidae ,Abelmoschus ,Ammonia ,Polysaccharides ,Materials Chemistry ,Animals ,Food science ,integumentary system ,Organic Chemistry ,bacterial infections and mycoses ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Shrimp ,Mucilage - Polysaccharide ,Seafood ,chemistry ,Color changes ,Polyvinyl Alcohol ,bacteria ,Colorimetry ,sense organs ,Naked eye ,0210 nano-technology ,Food Analysis - Abstract
In this work, a colorimetric film was designed for shrimp freshness monitoring by incorporating rose anthocyanins (RAs) in polyvinyl alcohol/okra mucilage polysaccharide (PVA/OMP) composite film. The presence of OMP changed the film-forming solution from Newtonian to non-Newtonian fluid. The addition of OMP and RAs decreased the crystalline of PVA due to the hydrogen bonds among RAs, OMP and PVA. An appropriate content of RAs and OMP could improve the film mechanical and barrier properties. The colorimetric film showed distinguishable color changes at pH 2-12 and was high sensitive to volatile ammonia. The target film of PVA/OMP-RAs could effectively monitor shrimp freshness in real time and the color changes were easily distinguished by naked eye, suggesting its potential in intelligent packaging for freshness monitoring of aquatic products and meat foods.
- Published
- 2020
11. Preparation and characterization of mucilage polysaccharide for biomedical applications
- Author
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Mohammed A. Fayidh, S. Babuskin, G. Archana, P. Azhagu Saravana Babu, K. Sabina, M. Sivarajan, M. Sukumar, and Kesavan Radhakrishnan
- Subjects
chemistry.chemical_classification ,Chromatography ,Tissue Engineering ,Polymers and Plastics ,Chemistry ,Methanol ,Chemical structure ,Organic Chemistry ,Extraction (chemistry) ,Temperature ,Chemical Fractionation ,Polysaccharide ,Acetone ,Plant Mucilage ,chemistry.chemical_compound ,Differential scanning calorimetry ,Mucilage ,Abelmoschus ,Solvents ,Materials Chemistry ,medicine ,Swelling ,medicine.symptom - Abstract
In the present investigation, the polysaccharide/mucilage from waste of Abelmoscus esculentus by modification in hot extraction using two different solvents (Acetone, Methanol) were extracted, characterized and further compared with seaweed polysaccharide for their potential applications. The percentage yield, emulsifying capacity and swelling index of this mucilage were determined. The macro algae and okra waste, gave high % yield (22.2% and 8.6% respectively) and good emulsifying capacity (EC%=52.38% and 54.76% respectively) with acetone, compared to methanol (11.3% and 0.28%; EC%=50%) (PH=7) while swelling index was greater with methanol than acetone extracts respectively. The infrared (I.R.) spectrum of the samples was recorded to investigate the chemical structure of mucilage. Thermal analysis of the mucilage was done with TGA (Thermal Gravimetric Analyzer) and DSC (Differential Scanning Calorimeter) which showed both okra and algal polysaccharide were thermostable hydrogels.
- Published
- 2013
12. Polysaccharide extraction from Abelmoschus esculentus: Optimization by response surface methodology
- Author
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Vahid Samavati
- Subjects
chemistry.chemical_classification ,Models, Statistical ,Chromatography ,Polymers and Plastics ,biology ,Plant Extracts ,Organic Chemistry ,Extraction (chemistry) ,Decoction ,Raw material ,Polysaccharide ,biology.organism_classification ,chemistry ,Abelmoschus ,Polysaccharides ,Yield (chemistry) ,Materials Chemistry ,Response surface methodology ,Mathematics - Abstract
Crude polysaccharide extraction from the Iranian Abelmoschus esculentus was performed using water decoction. Response surface methodology (RSM), based on a five level, four variable central composite rotatable design (CCRD), was employed to obtain the best possible combination of extraction time (X1: 0.5-6.5 h), extraction temperature (X2: 80-100 °C), number of extraction (X3: 1-5), and water to the raw material ratio (X4: 4-28) for maximum polysaccharide extraction. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods (ANOVA). The optimum extraction conditions were as follows: extraction time of 4.94 h, extraction temperature of 94.97 °C, number of extraction of 4, and the ratio of water to raw material of 21.74. Under these conditions, the experimental yield was 16.895±0.29%, which is well in close agreement with the value predicted by the model 16.916%.
- Published
- 2013
13. Effect of okra gum on the pasting, thermal, and viscous properties of rice and sorghum starches
- Author
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Shahzad Hussain, Abdellatif A. Mohamed, and Mohammed S. Alamri
- Subjects
Hot Temperature ,Materials science ,Polymers and Plastics ,Starch ,Viscosity ,Starch gelatinization ,chemistry.chemical_compound ,Differential scanning calorimetry ,Abelmoschus ,Plant Gums ,Materials Chemistry ,Shear stress ,Food science ,Sorghum ,biology ,Organic Chemistry ,food and beverages ,Viscometer ,Oryza ,biology.organism_classification ,Shear rate ,chemistry ,Agronomy ,Rheology - Abstract
The effect of okra gum (OE) on the physical properties of rice and sorghum starches was investigated using rapid visco-analyzer (RVA), Brookfield viscometer, differential scanning Calorimetry (DSC), and light microscopy. Starch was replaced with 5, 10, 15% OE weight basis (g/100 g). In the presence of OE, the peak and final viscosity as well as the setback of both starches were reduced. However, the difference between the theoretical and the measured setback was more than just can be attributed to the omitted starch. The DSC data of the blends showed higher peak temperature compared to the control, indicating slower starch gelatinization in the presence of OE. Brookfield profiles demonstrated increase in shear stress at higher shear rate confirming pseudoplasticity of the system (n < 1). Over all, it can be assumed that OE has influenced the properties of the starches, particularly, by decreasing viscosity, setback, and pseudoplasticity of the starch gels.
- Published
- 2012
14. Fine structure, physicochemical and antioxidant properties of LM-pectins from okra pods dried under different techniques.
- Author
-
Xu K, Martinez MM, Yang B, and Guo M
- Subjects
- Benzothiazoles chemistry, Biphenyl Compounds chemistry, Freeze Drying, Hot Temperature, Microwaves, Picrates chemistry, Sulfonic Acids chemistry, Sunlight, Abelmoschus, Antioxidants chemistry, Desiccation methods, Fruit, Pectins chemistry
- Abstract
This work investigates the effect of drying okra pods by different techniques [freeze-drying (FD), sun-drying (SD), oven-drying (OD) and microwave-drying (MD)] on the molecular structure, physicochemical and antioxidant properties of the subsequently extracted OP. Remarkably, although the degree of methyl esterification (∼41.1 %) remained similar among samples, the content of galacturonic acid (62.67-68.77 %), average number molecular weight (MnI: 758.8-808.5 kDa, MnII: 20.9-24.2 kDa), and to a greater extent the apparent viscosity of an aqueous solution of pectin molecules, water holding capacity (0.21-10.71 g/g) and emulsifying activity (42.3-72.7 %) and stability (38.6-53.5 %), decreased with the drying temperature in the order of FD-OP > SD-OP > OD-OP > MD-OP. On the other hand, only FD-OP presented a higher proportion of galactan and/or arabinan side chains [(Ara + Gal) / Rha = 12.37%] compared to the rest of the samples, with values ranging from 7.79 to 9.17%. FD-OP and SD-OP resulted in lower DPPH and ABTS radical scavenging activities., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
15. Colorimetric film based on polyvinyl alcohol/okra mucilage polysaccharide incorporated with rose anthocyanins for shrimp freshness monitoring.
- Author
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Kang S, Wang H, Xia L, Chen M, Li L, Cheng J, Li X, and Jiang S
- Subjects
- Ammonia analysis, Animals, Colorimetry, Food Safety, Penaeidae, Seafood analysis, Abelmoschus, Anthocyanins chemistry, Food Analysis methods, Polysaccharides chemistry, Polyvinyl Alcohol chemistry, Rosa
- Abstract
In this work, a colorimetric film was designed for shrimp freshness monitoring by incorporating rose anthocyanins (RAs) in polyvinyl alcohol/okra mucilage polysaccharide (PVA/OMP) composite film. The presence of OMP changed the film-forming solution from Newtonian to non-Newtonian fluid. The addition of OMP and RAs decreased the crystalline of PVA due to the hydrogen bonds among RAs, OMP and PVA. An appropriate content of RAs and OMP could improve the film mechanical and barrier properties. The colorimetric film showed distinguishable color changes at pH 2-12 and was high sensitive to volatile ammonia. The target film of PVA/OMP-RAs could effectively monitor shrimp freshness in real time and the color changes were easily distinguished by naked eye, suggesting its potential in intelligent packaging for freshness monitoring of aquatic products and meat foods., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
16. Influence of pH on mechanical relaxations in high solids LM-pectin preparations
- Author
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Stefan Kasapis, Katerina Alba, and Vassilis Kontogiorgos
- Subjects
Quantitative Biology::Biomolecules ,Polymers and Plastics ,Chemistry ,Organic Chemistry ,Kinetics ,Analytical chemistry ,Hydrogen-Ion Concentration ,Q1 ,Vitrification ,Viscoelasticity ,Dissociation (chemistry) ,Polyelectrolyte ,Solvent ,Condensed Matter::Soft Condensed Matter ,Differential scanning calorimetry ,Abelmoschus ,Materials Chemistry ,Physical chemistry ,Pectins ,QD ,Glass transition ,Macromolecule - Abstract
The influence of pH on the mechanical relaxation of LM-pectin in the presence of co-solute has been investigated by means of differential scanning calorimetry, ζ-potential measurements and small deformation dynamic oscillation in shear. pH was found to affect the conformational properties of the polyelectrolyte altering its structural behaviour. Cooling scans in the vicinity of the glass transition region revealed a remarkable change in the viscoelastic functions as the polyelectrolyte rearranges from extended (neutral pH) to compact conformations (acidic pH). This conformational rearrangement was experimentally observed to result in early vitrification at neutral pH values where dissociation of galacturonic acid residues takes place. Time-temperature superposition of the mechanical shift factors and theoretical modeling utilizing WLF kinetics confirmed the accelerated kinetics of glass transition in the extended pectin conformation at neutral pH. Determination of the relaxation spectra of the samples using spectral analysis of the master curves revealed that the relaxation of macromolecules occurs within ~0.1 s regardless of the solvent pH.
- Published
- 2015
17. Purification, characterization and immunomodulating activity of a polysaccharide from flowers of Abelmoschus esculentus
- Author
-
Weiwei Feng, Wei Wang, Qian Li, Xiangyang Wu, Huiyu Wu, Ting Zhao, Daheng Zheng, Mohammed Takase, Zheng Wei, Liuqing Yang, and Ye Zou
- Subjects
Cytotoxicity, Immunologic ,Polymers and Plastics ,Transcription, Genetic ,Rhamnose ,Drug Evaluation, Preclinical ,Nitric Oxide Synthase Type II ,Flowers ,Polysaccharide ,Nitric Oxide ,Cell Line ,chemistry.chemical_compound ,Mice ,Phagocytosis ,Abelmoschus ,Polysaccharides ,Materials Chemistry ,Animals ,Humans ,Immunologic Factors ,Secretion ,RNA, Messenger ,Cellulose ,Transcription factor ,chemistry.chemical_classification ,Cell Nucleus ,Molecular mass ,biology ,Tumor Necrosis Factor-alpha ,Macrophages ,Organic Chemistry ,NF-kappa B ,Water ,Hep G2 Cells ,biology.organism_classification ,Antineoplastic Agents, Phytogenic ,Up-Regulation ,Molecular Weight ,chemistry ,Biochemistry ,Solubility ,Galactose - Abstract
A water-soluble polysaccharide (OFPS11) was obtained from okra (Abelmoschus esculentus) flowers using aqueous extraction and purification with DEAE-52 cellulose and Sephacryl™ S-500 column. Its preliminary characterization and immunomodulating activity were investigated. Results showed that OFPS11 is mainly composed of galactose and rhamnose in a molar ratio of 2.23:1 with molecular mass of 1,700 kDa. RAW264.7 cells pretreated with OFPS11 significantly inhibited the proliferation of HepG-2 cells. Additionally, OFPS11 enhanced the phagocytic ability and induced the elevation of NO production, TNF-α and IL-1β secretion of RAW264.7 cells. Furthermore, OFPS11 promoted both the expression of iNOS protein and of iNOS and TNF-α mRNA. OFPS11 can strongly increase NF-κB levels in nucleuses, which is an important transcription factor that can modulate expressions of iNOS, NO and TNF-α. These outcomes support that OFPS11 exerts its antitumor activity by probably stimulating macrophage activities through nuclear NF-κB pathway.
- Published
- 2014
18. Polysaccharide extraction from Abelmoschus esculentus: optimization by response surface methodology.
- Author
-
Samavati V
- Subjects
- Models, Statistical, Plant Extracts, Abelmoschus, Polysaccharides isolation & purification
- Abstract
Crude polysaccharide extraction from the Iranian Abelmoschus esculentus was performed using water decoction. Response surface methodology (RSM), based on a five level, four variable central composite rotatable design (CCRD), was employed to obtain the best possible combination of extraction time (X1: 0.5-6.5 h), extraction temperature (X2: 80-100 °C), number of extraction (X3: 1-5), and water to the raw material ratio (X4: 4-28) for maximum polysaccharide extraction. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods (ANOVA). The optimum extraction conditions were as follows: extraction time of 4.94 h, extraction temperature of 94.97 °C, number of extraction of 4, and the ratio of water to raw material of 21.74. Under these conditions, the experimental yield was 16.895±0.29%, which is well in close agreement with the value predicted by the model 16.916%., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
19. Effect of okra gum on the pasting, thermal, and viscous properties of rice and sorghum starches.
- Author
-
Alamri MS, Mohamed AA, and Hussain S
- Subjects
- Hot Temperature, Rheology, Viscosity, Abelmoschus, Oryza, Plant Gums chemistry, Sorghum, Starch chemistry
- Abstract
The effect of okra gum (OE) on the physical properties of rice and sorghum starches was investigated using rapid visco-analyzer (RVA), Brookfield viscometer, differential scanning Calorimetry (DSC), and light microscopy. Starch was replaced with 5, 10, 15% OE weight basis (g/100 g). In the presence of OE, the peak and final viscosity as well as the setback of both starches were reduced. However, the difference between the theoretical and the measured setback was more than just can be attributed to the omitted starch. The DSC data of the blends showed higher peak temperature compared to the control, indicating slower starch gelatinization in the presence of OE. Brookfield profiles demonstrated increase in shear stress at higher shear rate confirming pseudoplasticity of the system (n<1). Over all, it can be assumed that OE has influenced the properties of the starches, particularly, by decreasing viscosity, setback, and pseudoplasticity of the starch gels., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
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