Modification of poly (styrene-co-divinyl benzene) porous materials for peptides enrichment and separation

2018 ◽  
Vol 47 (5) ◽  
pp. 406-414 ◽  
Author(s):  
Yi Liu ◽  
Hao Wang ◽  
Yongfeng Liu ◽  
Meng Shi ◽  
Duolong Di

PurposeThe purpose of this paper is to focus on the selection of the optimum porous material modified with poly-dopamine coating for peptides enrichment. The adsorption behaviors for peptides and the antioxidant capacity of peptides fraction purified by the porous materials were investigated.Design/methodology/approachThe optimum porous material with the highest adsorption capacity for peptides was selected for surface modification. The surface modified porous material was characterized by SEM, nitrogen adsorption-desorption isotherm and color change.FindingsThe results showed that the porous material was successfully modified with poly-dopamine coating. Adsorption capacity for peptides of the modified porous material was enhanced compared to the original porous material. Antioxidant capacity of peptides fraction enriched by the modified porous material was much higher than that enriched by the original porous material, indicating that the introduction of poly-dopamine coating was inclined to enrich peptides with certain amino acid residues.Research limitations/implicationsThe structures of peptides are a bit not clear, which is the subject of future investigation.Practical implicationsThis contribution provides a method to design and prepare porous materials with poly-dopamine coating to separate and enrich peptides or peptides fraction with high antioxidant capacity.Originality/valueIt showed that polarity, surface area, pore diameter and interactions were contributed to high adsorption capacity. The peptides fraction purified by the modified porous material showed excellent antioxidant capacity through results of reduction of DPPH radical, because of the enrichment of the peptides with certain amino acids residues which were considered to enhance radical scavenging capacity. This paper provides new insights into designing and preparing porous materials with poly-dopamine coating to enrich peptides fraction with high antioxidant capacity.

2020 ◽  
Vol 32 (3) ◽  
pp. 390-401
Author(s):  
Jiyoung Park ◽  
Youngmi Park

Purpose Equisetum arvense L. (Equisetum) is a weed that is very difficult to remove because of its deep roots. The purpose of this paper is to examine the dyeability and antioxidant activity of Equisetum extracted from hot water. Design/methodology/approach Dry Equisetum was extracted at 100°C for 2 h, and its dyeability according to time, temperature and repetition cycle, and the mordant effect by skim milk powder were confirmed. The color change according to the K/S, fastness to rubbing, light, sweat and washing, UV protection rate and antioxidant activity were evaluated. Findings UV‒Vis spectroscopy showed that the Equisetum extract contained a flavonoid compound. The addition of Equisetum to artificial silk produced the greatest color difference when dyed at 60°C for 1 h, and the K/S value increased slightly after the pre-mordant treatment. In the fastness test, light and washing had no significant effect, but the fastness to rubbing was very good at Grades 4 and 5, and there was also a considerable improvement in the UV protection rate. The antioxidant activity of the extract was confirmed by an analysis of the radical scavenging ability through the DPPH (1,1-diphenyl 2-picryl-hydrazyl) and ABTS ([2,2’- azino-bis (3-ethylbenzothialzoline-6-sulfonic acid) diammonium salt]) tests. Originality/value These results revealed a new natural antioxidant-containing dyestuff, weed grass, which is easy to obtain, easy to use as a dyeing material and has excellent antioxidant activity in an extracted dye solution and dyeing fabric.


2017 ◽  
Vol 46 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Nordiyanah Anuar ◽  
R.M. Taha ◽  
Noraini Mahmad ◽  
Sadegh Mohajer ◽  
Siti Aisha Na’illa Che Musa ◽  
...  

Purpose The aim of the present study is to gain correlation between saffron colours, their antioxidant capacity and the constituents of the secondary metabolites of three different saffron samples commonly available in the Malaysian market. Design/methodology/approach In this study, saffron samples imported from Iran, Spain and Kashmir were extracted using methanol and the total antioxidant capacity were analysed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Ultra-high performance liquid chromatography (UHPLC) and electrospray ionization coupled with mass spectrometry (ESI-MS/MS) were then used to identify secondary metabolites present in the saffron crude extracts. The colour variation of the saffron extract was expressed by the CIELAB colorimeter in terms of lightness (L*), greenness (a*), yellowness (b*), chroma (C) and hue angle (H°). Principle component analysis (PCA) was carried out to analyse the similarities and correlation between variables. Findings This study reveals that antioxidant has a positive correlation with flavanols, especially quercetin and kaempferol. In addition, colour appearance is not necessarily an indicator for the antioxidant level. Research limitations/implications The major classes of polyphenolics identified in saffron methanolic crude extract are flavonoids and phenolic acids. Further improvements in the extraction and identification methods may find other compounds that could attribute to the visual factors and antioxidant capacity as a complement for this preliminary study. Practical implications This analysis provides comparison basis and valuable information for saffron consumers in Malaysia depending on the consumers’ purpose of whether to have a certain desired colour or health benefits. Originality/value A comparative study about saffron product available in Malaysian market is original. To the best of the authors’ knowledge, this is the first attempt of evaluation on a saffron product that has been carried out in Malaysia.


2017 ◽  
Vol 69 (2) ◽  
pp. 88-94 ◽  
Author(s):  
Zhining Jia ◽  
Yanhong Yan ◽  
Weizheng Wang

Purpose The content of pore-foaming agent directly affects pore characteristics and oil-absorption properties of polyimide (PI) porous materials, which further influence the tribological performance of PI pore material. This research paper aims to discuss these issues. Design/methodology/approach Thermal vacuum molding technology was adopted to prepare PI porous material with different structures by changing the content of the pore-forming agent to control pore size and porosity of the PI material. PI oil-bearing materials were obtained by vacuum oil immersion. The tribological experiments of PI oil-bearing materials were conducted on the CETR friction and wear testing machine. Findings The study results showed that PI porous material with a specific structure can be obtained by controlling the content of a pore-forming agent. In a certain range, with the increase in the content of the pore-forming agent, the average pore size and porosity increased, also the oil content increased, which means that the friction coefficient and wear rate decreased to a very large extent, and antifriction and wear resistant properties of the PI porous materials greatly improved. When the content of the pore-forming agent exceeds 8 per cent, the wear rate and friction coefficient of the PI porous materials began to increase. Originality/value Because the complexity of the tribological system consists of lubricating oil, porous material and friction pair, the physical understanding of the mechanism of this process remains limited. Therefore, the present research was undertaken to identify the phenomena involved, which will provide practical guidance for the tribological application in the field of bearing parts.


2013 ◽  
Vol 43 (2) ◽  
pp. 116-127 ◽  
Author(s):  
Muhammad Nadeem Asghar ◽  
Javaid Akhtar ◽  
Muhammad Shafiq ◽  
Iram Nadeem ◽  
Muhammad Ashfaq ◽  
...  

PurposeThe cowpea plant, being affordable and protein‐rich, is considered poor man's meat. The aim of this paper is to undertake a detailed investigation regarding in vitro total antioxidant capacity (TAC) and chemical constituents of the vegetable oils from seeds of this plant, taking its nutritional value into consideration.Design/methodology/approachVegetable oils of different indigenous cowpea varieties were obtained using soxhelt extraction assembly and subjected to GC‐MS analyses and various antioxidant assays including 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulpohonic acid) (ABTS) radical cation scavenging, ferr, 2.2′‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging, total phenolic contents (TPC), lipid peroxidation inhibition, and iron chelation activity.FindingsVarious chemical constituents including different hydrocarbons, tocopherols, ketones, fatty esters, estragole and cedrene were identified. TPCs were found to be 5.439, 5.7279, 7.6126, 6.7573 and 10.0591 mg/L gallic acid equivalent for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively. Employing ABTS radical decoloration assay a significant linear correlation (R2=0.997, 0.996, 0.997, 0.996 and 0.997 for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively) was found between the percent inhibition of ABTS radical cation and the amount of vegetable oils. The percent inhibition of the Fe(II)‐Ferrozine complex formation was found to be 29.45, 53.76, 82.91, 86.59 and 57.87 for the same varieties, respectively.Originality/valueGC‐MS and standard in vitro antioxidative capacity analyses data clearly demonstrated the potency of the cowpea as antioxidant and radical scavenger plant which may be used as a good source of natural antioxidants. The plant seeds may prove a better and cost‐effective substitute of expensive food items.


J ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 193-205
Author(s):  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Taile Leswifi ◽  
Maurice S. Onyango

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.


Foods ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 281 ◽  
Author(s):  
Saleha Akter ◽  
Michael E. Netzel ◽  
Ujang Tinggi ◽  
Simone A. Osborne ◽  
Mary T. Fletcher ◽  
...  

Terminalia ferdinandiana (Kakadu plum) is a native Australian plant containing phytochemicals with antioxidant capacity. In the search for alternatives to synthetic preservatives, antioxidants from plants and herbs are increasingly being investigated for the preservation of food. In this study, extracts were prepared from Terminalia ferdinandiana fruit, leaves, seedcoats, and bark using different solvents. Hydrolysable and condensed tannin contents in the extracts were determined, as well as antioxidant capacity, by measuring the total phenolic content (TPC) and free radical scavenging activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Total phenolic content was higher in the fruits and barks with methanol extracts, containing the highest TPC, hydrolysable tannins, and DPPH-free radical scavenging capacity (12.2 ± 2.8 g/100 g dry weight (DW), 55 ± 2 mg/100 g DW, and 93% respectively). Saponins and condensed tannins were highest in bark extracts (7.0 ± 0.2 and 6.5 ± 0.7 g/100 g DW). The antimicrobial activity of extracts from fruit and leaves showed larger zones of inhibition, compared to seedcoats and barks, against the foodborne bacteria Listeria monocytogenes, Bacillus cereus, Methicillin resistant Staphylococcus aureus, and clinical isolates of Pseudomonas aeruginosa. The minimum inhibitory concentration and minimum bactericidal concentration in response to the different extracts ranged from 1.0 to 3.0 mg/mL. Scanning electron microscopy images of the treated bacteria showed morphological changes, leading to cell death. These results suggest that antioxidant rich extracts of Terminalia ferdinandiana fruits and leaves have potential applications as natural antimicrobials in food preservation.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1091 ◽  
Author(s):  
Dengke Li ◽  
Daoqing Chang ◽  
Bilong Liu

The diffuse sound absorption was investigated theoretically and experimentally for a periodically arranged sound absorber composed of perforated plates with extended tubes (PPETs) and porous materials. The calculation formulae related to the boundary condition are derived for the periodic absorbers, and then the equations are solved numerically. The influences of the incidence and azimuthal angle, and the period of absorber arrangement are investigated on the sound absorption. The sound-absorption coefficients are tested in a standard reverberation room for a periodic absorber composed of units of three parallel-arranged PPETs and porous material. The measured 1/3-octave band sound-absorption coefficients agree well with the theoretical prediction. Both theoretical and measured results suggest that the periodic PPET absorbers have good sound-absorption performance in the low- to mid-frequency range in diffuse field.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 48
Author(s):  
Anh Dao Thi Phan ◽  
Maral Seidi Damyeh ◽  
Saleha Akter ◽  
Mridusmita Chaliha ◽  
Michael E. Netzel ◽  
...  

Terminalia ferdinandiana (Kakadu plum), belonging to the family Combretaceae, is endemic to Australia and has a long history of traditional medicinal applications and food cuisine by the Australian Indigenous people. This study investigated the effects of maturity stages on the morphology, physicochemical parameters (total soluble solids (TSS), total acid content (TAC), and pH), soluble sugar profile and antioxidant capacity of Kakadu plum (KP) fruits that were wild harvested from different trees and classified into four different maturity stages (immature to mature). TSS and TAC were determined by standard assays/procedures, main sugars by UHPLC–MS/MS and antioxidant capacity (total phenolic content (TPC) and DPPH free radical scavenging capacity) by spectrophotometry. The results showed that soluble sugars (glucose, sucrose and fructose) ranging from 1.3 to 17.7% dry weight (DW), TSS (17.0–52.7% DW) and TAC (1.3–6.7% DW) increased with maturity. However, antioxidant capacity (TPC in the range of 7.4–21.9% DW and DPPH free radical scavenging capacity from 22 to 76% inhibition at the extract concentration of 20 g·L−1) did not follow the same trend as the one observed for soluble sugars, TSS and TAC. These differences were associated with the tree-to-tree variability as a consequence of the wild harvest condition. This study provides important information to both the KP industry and Indigenous enterprises regarding the selection of the appropriate maturity stage to harvest KP fruit to target for different markets (e.g., low-sugar vs. high-sugar fruit).


2021 ◽  
Vol 2 (5) ◽  
pp. 6608-6618
Author(s):  
Eva Coronel ◽  
Silvia Caballero ◽  
Gabriela Gonzalez ◽  
Miho Sunguino ◽  
Laura Mereles

Los frutos de Anisocapparis speciosa son nativas de la Ecoregión del Gran Chaco, crecen de manera silvestre en todo este territorio, su pulpa y semillas son comestibles y muy apreciadas por las poblaciones indígenas que lo habitan, además de otros usos con propiedades medicinales atribuidas por conocimientos etnobotánicos, pero no se tienen datos sobre la composición de estos frutos regionales y sus potenciales aplicaciones. El objetivo del presente trabajo fue evaluar la composición de la pulpa y semillas de frutos en estado maduro, y el potencial antioxidante en diferentes estadíos de madurez. La composición proximal, el contenido de minerales, vitamina C y solidos solubles se realizaron según metodologías oficiales de la AOAC.  Los fenoles totales se determinaron por el método de Folin Ciocalteau y la capacidad antioxidante total por medio de la inhibición del radical ABTS. Los componentes mayoritarios en pulpa y semillas fueron carhobidratos y fibra alimentaria. La pulpa madura posee un buen contenido de vitamina C (20 mg/100g). El contenido de fenoles y capacidad antioxidante total fue mayor en la pulpa que en la semillas en estados inmaduros. Los frutos de Anisocapparis speciosa pueden representar una buena fuente de carbohidratos, fibra alimentaria, Mg y vitamina C en la dieta. La pulpa y semillas son fuentes de antioxidantes naturales. Estudios futuros sobre métodos postcosecha, almacenamiento y procesamiento serán necesarios para potenciar su uso y re-valorización en el marco de la Seguridad alimentaria en la población regional.   The native Anisocapparis speciosa fruits from Gran Chaco Ecoregion, they grow wild throughout this territory, their edible pulp and seeds are highly appreciated by the indigenous populations that inhabit it, in addition to other uses with medicinal properties attributed by ethnobotanicals knowledge, but there are no data on the composition of these regional fruits and their potential applications. The aims of the present work were to analyze the pulp and seeds composition of fruits in the ripe state, and the antioxidant potential in different stages of maturity. The proximal composition, minerals content, vitamin C and soluble solids were carried out according to official AOAC methodologies. The total phenolics compounds (TPC) by the Folin Ciocalteau method and the total antioxidant capacity by means of the inhibition of the radical ABTS were evaluated. The main components in pulp and seeds were carbohydrates and dietary fiber. The ripe pulp has a good content of vitamin C (20 mg/100g). The content of TPC and total antioxidant capacity (ABTS radical scavenging) was higher in pulp than in the seeds, in immature stages. The Anisocapparis speciosa fruits can represent a good source of carbohydrates, dietary fiber, Mg and vitamin C in the diet of regional populations. The pulp and seeds are sources of natural antioxidants. Future studies on post-harvest, storage and processing methods will be necessary to enhance its use and re-valorization within the Food Security framework.  


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Naresh Yarramsetty ◽  
Naveen Sharma ◽  
Modumudi Lakshmi Narayana

Purpose This study aims to investigate the effect of porous material (clay pots) and it is facing on the productivity performance of a pyramid type solar still. The clay pots are placed in the basin facing up and facing down. The numbers of clay pots considered were 9 and 25, and its performance was compared with normal (0 clay pots) solar still. Design/methodology/approach The pyramid solar water distillation system has been designed, fabricated and tested under the actual environmental conditions of Kanchikacherla (16.6834 0N, 80.3904 0E), Andhra Pradesh, India. The solar still is used to produce the fresh water and hot water simultaneously from the brackish (i.e. containing dissolved salts) feed water for domestic applications. From open literature, it was established that the rate of evaporation is higher when the flowing water is held for a longer duration on the black color absorber plate, thereby leading to an increase in productivity of freshwater. Therefore, the pyramid solar still has been tested for smooth absorber plate and the absorber plate with porous heat storage material. Findings The porous material increases the production rate of freshwater compared to a base plate. However, the pyramid still with clay pots has higher productivity at a lower temperature because of the porosity effect. Originality/value The total dissolved solids, electrical conductivity and pH of the distilled water and the saline water have also been measured and compared.


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