Optimum Conditions For Purification Research Articles

Synergistic ultrasound pulsed electric field extraction of litchi peel polyphenols and determination of their properties

The effects of pulsed electric field combined with ultrasound (PEF-US) on the recovery of polyphenols from litchi peels were investigated. In addition, the optimal purification parameters for polyphenol extracts and their biological activities were also explored in this study. Single-factor and orthogonal experiments were used to optimize the extraction conditions of polyphenols. After optimization, the total phenol content (TPC) of the sample extracted by PEF-US was 2.30 times higher than that of the sample extracted by traditional hot-water extraction. The mechanism of PEF-US enhancing polyphenol recovery was also revealed by morphological analysis of the powder surface. LX-7 was the best resin by comparing the purification effect of nine macroporous resins. The optimum conditions for purification of litchi peel polyphenols by LX-7 resin were also optimized through adsorption and desorption experiments. UHPLC-MS and HPLC results revealed that gentisic acid, catechin, procyanidin A2 and procyanidin B1 are four main substances in purified samples. The results of bioactivity experiments showed that the purified polyphenol samples had strong antioxidant and antibacterial activity. Overall, PEF-US is an efficient method for recovering polyphenols from litchi peels. Our study also provides a strategy for the comprehensive utilization of fruit processing waste.

Acid leaching technology for post-consumer gypsum purification.

Contaminants and water-soluble salts present in mechanically recycled gypsum from refurbishment and demolition (post-consumer) plasterboard waste limit its use as a secondary raw material in plasterboard manufacturing. This research addresses this limitation, developing a novel acid leaching purification technology combined with an improved mechanical pre-treatment for post-consumer gypsum valorization. Laboratory-scale acid leaching purification was performed with a borosilicate beaker, hot plate, and overhead stirrer. Stuccos were produced after calcination of gypsum at 150 °C for 3 hours. Samples were characterized through X-ray fluorescence, X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy and particle size analysis. Acid leaching at 90 °C for 1 h using a 5 wt% sulfuric acid solution was revealed to be the optimum purification conditions. Stuccos produced from purified gypsum under optimum conditions had similar initial setting times to that of a commercial stucco but with higher water demand, which could be reduced by optimizing the calcination conditions. A magnesium-rich gypsum was precipitated from the wastewater. Purified post-consumer gypsum with > 96 wt% chemical purity and calcium sulfate dihydrate content was produced. The research recommends acid neutralization prior filtration, use of gypsum particles < 2 mm in size, and stirring speed of 50 rpm to reduce the economic and environmental impacts of the acid leaching purification process at industrial scale. The magnesium-rich gypsum could potentially be marketed as soil fertilizer.

Acid leaching technology for post-consumer gypsum purification

Background: Contaminants and water-soluble salts present in mechanically recycled gypsum from refurbishment and demolition (post-consumer) plasterboard waste limit its use as a secondary raw material in plasterboard manufacturing. This research addresses this limitation, developing a novel acid leaching purification technology combined with an improved mechanical pre-treatment for post-consumer gypsum valorization. Methods: Laboratory-scale acid leaching purification was performed with a borosilicate beaker, hot plate, and overhead stirrer. Stuccos were produced after calcination of gypsum at 150 °C for 3 hours. Samples were characterized through X-ray fluorescence, X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy and particle size analysis. Results: Acid leaching at 90 °C for 1 h using a 5 wt% sulfuric acid solution was revealed to be the optimum purification conditions. Stuccos produced from purified gypsum under optimum conditions had similar initial setting times to that of a commercial stucco but with higher water demand, which could be reduced by optimizing the calcination conditions. A magnesium-rich gypsum was precipitated from the wastewater. Conclusions: Purified post-consumer gypsum with &gt; 96 wt% chemical purity and calcium sulfate dihydrate content was produced. The research recommends acid neutralization prior filtration, use of gypsum particles &lt; 2 mm in size, and stirring speed of 50 rpm to reduce the economic and environmental impacts of the acid leaching purification process at industrial scale. The magnesium-rich gypsum could potentially be marketed as soil fertilizer.

Studies on the Processing of Fine Dusts from the Electric Smelting of Ilmenite Concentrates to Obtain Titanium Dioxide

This article presents studies on the ammonium fluoride processing of dusts from the reduction smelting of ilmenite concentrate with separation of silicon to obtain titanium dioxide. Optimal conditions for pyrohydrolysis of titanium fluorides were determined. The effects of temperature and duration on the process were studied. The optimal conditions for pyrohydrolysis of titanium fluorides were a temperature of 600 °C and duration of 240-300 min. The degree of titanium fluoride conversion to titanium oxide was 99.5% at these conditions. Titanium dioxide obtained by pyrohydrolysis of titanium fluorides was purified from iron, chromium, and manganese impurities. The effect of hydrochloric acid solution concentration, S:L ratio, and the process duration on the purification degree of titanium fluoride pyrohydrolysis was studied. The following optimum purification conditions were determined: hydrochloric acid solution concentration 12.5-15 wt%, temperature 25-30 °C, S:L = 1:6÷8, duration 20-30 min. The purified titanium dioxide consisted mainly of anatase. The pigmented titanium dioxide of rutile modification with 99.8 wt% TiO2 was obtained after calcination at 900 °C for 120 min.

Isolation, structural modification, characterization, and bioactivity of polysaccharides from Folium Isatidis

The purification process of Folium Isatidis polysaccharide (FIP) was optimized by response surface method (RSM) using AB-8 macroporous resin. A major homogeneous polysaccharide, named FIP-Ⅱ, was purified from FIP through DEAE-650 M and Sephadex G-75 column chromatography. The structure of the FIP-Ⅱ was investigated through the combination of HPLC, GC, FT-IR, sequential acid hydrolysis, peroxide oxidation, Smith degradation, and NMR analysis. Then, the sulfated, phosphorylated, and carboxymethylated derivatives of FIP-Ⅱ, namely FIP-Ⅱ-S, FIP-Ⅱ-P, and FIP-Ⅱ-C, were prepared. Their structures were characterized by extensive analysis of chromatographic and spectroscopic methods including UV, HPLC, GC, FT-IR, Congo red, CD, SEM-EDX, XRD, TG, DTG, and DSC. Results of RSM showed that optimum purification conditions were elution flow rate 2.76 BV/ h, the sample concentration 2.03 mg/mL, and the elution volume was 1.26 BV. The average comprehensive score of purification was up to 76.28%. FIP-Ⅱ and its derivatives were heteropolysaccharides composed of different molar ratios of rhamnose, arabinose, xylose, mannose, glucose, and galactose, with a molecular weight of 775.64, 911.75, 1288.31, and 1013.61 kDa. The structure modification influences the solution conformation, surface morphology, crystalline nature, and thermal properties of the FIP-Ⅱ and its derivatives. Antioxidant activity tests showed that structure modification could significantly enhance the activity of the polysaccharides differently. It could be a potential ingredient in the functional food and pharmaceutical industry.

Preparation and characterization of antioxidant flavonoid-enriched extract from saffron by-product: a combination of ultrasound-assisted extraction and macroporous resin purification

The stigma of saffron, a precious spice widely used in the world, takes only 7.4% (w/w) of the total weight of the flower, resulting in wasting the rest 92.6% of the flower. The utilization of the waste saffron floral bio-residues (SFB) has hence attracted people’s attention. In this paper, ultrasound-assisted extraction (UAE) associated with macroporous resin (MPR) purification step was successfully applied to enrich antioxidant flavonoid in SFB extract for the first time, resulting in significant increase in flavonoid content compared with other extraction method reported in literatures. The yield of the extract was up to 10%, and the content of kaempferol-3-O-sophoroside (KS) in the obtained extract was more than 50%, which was much higher than the total flavonoid content (2.05–19.2%) reported in other literatures. UAE procedure was optimized by studying the influence of parameters, e.g., extracting solvent, time, temperature and sample–solvent ratio, based on contents of KS and delphinidin-3,5-di-O-glucoside (DG) and the antioxidant activity of the extract. Further enrichment of flavonoid was achieved by D-101 MPR with optimum purification conditions. Furthermore, 52 flavonoids, 8 alkaloids and 10 polyols were identified or putatively characterized from the SFB extract using UPLC-MS, and the contents of KS and DG were determined to be 501.90 and 22.01 mg/g, respectively. Besides, the SFB flavonoid extract showed good antioxidant activities with IC50 33.79 μg/mL for DPPH scavenging effect and 39.65 μmol/mg trolox for ORAC values

Variations of binding, washing, and concentration of imidazole on purification of recombinant Fim-C Protein Salmonella typhi with Ni-NTA Resin

Typhoid fever is an endemic disease in Indonesia. Prevention of typhoid fever can be done by administering vaccines. It is known that one of the raw materials for vaccines is a recombinant protein. This study aims to obtain information on the optimum conditions for purification of Salmonella typhi Fim-C recombinant protein with Ni-NTA resin as vaccine raw material. The three main stages of the purification process in this study were binding, washing, and elution of S. typhi Fim-C recombinant proteins. The binding and washing variations of recombinant proteins were carried out twice, four times and six times, while the elution process was carried out at imidazole concentrations of 200 mM, 250 mM, and 300 mM. Purification with a binding process four and six times gave almost the same intensity of S. typhi Fim-C protein bands. Whereas protein was elution at an imidazole concentration of 300 mM showed higher band instability. The results of characterization using SDS-PAGE and analysis using software ImageJ gel analysis showed that the longer the incubation time and the repetition of the binding process, the more protein bound to the resin. Furthermore, the more washing processes are obtained the purer proteins. Based on the data obtained it can be concluded that the purification of the S. typhi Fim-C recombinant protein was optimum at a four-time binding process, six times washing and a 300 mM imidazole concentration. These results are expected to be the basis for recombinant protein refining on a pilot scale and industry scale in better vaccine preparation.

Effect of plastic carbon fiber-biofilm technology on landscape water purification

In this study, a new type of plastic carbon fiber filler was applied to biofilm technology. The optimum purification conditions for eutrophic landscape water were discussed by controlling the filling amount, aeration volume and pollutant concentration. The activated sludge from the sewage treatment plant is used for aeration and filming to explore the effect of the filler on the purification effect of the landscape water body. Studies have shown that the composite filler has a good removal effect on CODcr, TN and TP in eutrophic water, and is a highly efficient new water treatment material.

Purification of Amygdalin from the Concentrated Debitterizing-Water of Apricot Kernelsusing XDA-1 Resin

In this study, six macroporous resins were screened on their adsorption and de-adsorption characteristics for the amygdalin in the debitterizing wastewater concentrate (DWC). The results indicate that the XDA-1 resin exerts good adsorption and de-adsorption capacities on the amygdalin. In order to further confirm its feasibility, the factors affecting the capacity of adsorption and de-adsorption, and its adsorption mechanisms were also investigated. The results suggest that the optimum purification conditions were as follows: loading concentration of samples with 78.05 mg/mL, flow rate of 2 mL/min, and de-adsorption with 80% ethanol solution. The recovery rate was 88.75% and the relative content achieved 61.58% after purification by XDA-1 resin. The Freundlich model can be used to describe the entirety of the exothermic and physical adsorption processes. In summary, the conclusion which can be made from this research is that the wastewater generated from the debitterizing of apricot kernels can be well treated by resin to recycle the amygdalin and reduce its pollution to environment.

Recovery of phosphate as struvite from low-temperature combustion sewage sludge ash (LTCA) by cation exchange

As a phosphorus-rich material, low-temperature combustion sewage sludge ash (LTCA) contains over 9 wt% content of phosphorus (P) and a large proportion of impurities, especially the content of Fe arrives at 14.59 wt%. To fully utilize LTCA as a fertilizer, this study investigated a procedure for P recovery from LTCA via struvite crystallization with fewer impurities. The adsorption characteristics of P and Fe by cation exchange resin (CER) were explored by simulating using the macroscopic parametric equation Thomas model. Optimum purification conditions for P-rich leachate by cation exchange column method were determined. Results showed that approximately 97.21 wt% of P was extracted from LTCA at HCl concentration of 0.8 M and liquid/solid ratio of 20.0 ml/g. More than 90 wt% of impurities could be detached by making P-rich leachate flow through cation exchange bed filled by CER at 300 ml/h. The macroscopic parametric equation Thomas model could clearly describe the adsorption characteristics of Fe in P-rich leachate by CER. Theoretical basis for purification of high concentration Fe in P-rich leachate by CER was provided. Approximately 84.04 wt% of total P in LTCA was recovered as struvite crystal which had low concentrations of heavy metals (5.96 mg/kg for Cr, 45.21 mg/kg for Cu, 29.67 mg/kg for Ni, 2.24 mg/kg for Pb, and 290.6 mg/kg for Zn) and could be eco-friendly for agricultural application. X-ray diffraction and SEM-EDS analysis validated the formation of struvite.

Combined ultrafiltration and electrodeionization techniques for microbial xylitol purification

Oil palm empty fruit bunch (OPEFB) is biomass waste from crude palm oil industry that can be utilized for xylitol production. In recent years, xylitol production is dominated by a microbial fermentation method where the fermentation product contains many impurities, thus requires further purification and separation processes. In this work, ultrafiltration (UF) and electrodeionization (EDI) membranes were used for purification of xylitol from either model solution or OPEFB hydrolysate that has been fermented by Debaromyces hansenii. First, the optimum conditions for purification of xylitol from xylose, acetic acid, and salts in model solution using EDI were evaluated. The results showed that the optimum current density, concentrate flow rate, and diluate flow rate was found to be 22.5A/m2, 0.4m/s, and 0.5m/s, respectively. Meanwhile, validation experiment using the OPEFB hydrolysate fermentation broth showed that UF-EDI membrane configuration was able to remove 99% of microorganism and biomass, 99% pigment, >46% of xylose, and >99% ionic impurities including >90% acetic acid with a loss of xylitol about 30–50%.

Optimization of Aqueous Two-Phase System (ATPS) of Recombinant Bromelain by Response Surface Methodology

Recombinant bromelain is a protease that was partially purified using aqueous two-phase system (ATPS). The process variables (pH, PEG 6000 and potassium phosphate concentration) were optimized on enzyme activity and partition coefficient using response surface methodology (RSM) based on a face-centered central composite design (FCCCD) model. The optimum conditions for purification were at 18.47% [w/w] PEG6000 and 13% [w/w] potassium phosphate, pH 7.0 with enzyme activity was obtained as 0.272±0.0036 unit m/L, and partition coefficient as 1.394±0.093. The recombinant bromelain was preferentially partitioned into the top phase and the band was reduced in contrast to crude sample on SDS-PAGE gel.

Optimization of Ellagic Acid Purification from Pomegranate Husk by Antisolvent Recrystallization

AbstractEllagic acid (EA) was produced from pomegranate husk by extraction of tannins followed by acid hydrolysis and purified by antisolvent recrystallization. Response surface methodology, based on a five‐level, four‐variable central composite design, was employed to find the optimum purification conditions. Under these conditions, high purity and yield of EA was obtained in close agreement with the predicted values by the model. Analyzes of surface morphology and in vitro percutaneous absorption experiments of EA let conclude that the granule morphology of the purified EA was significantly different from the crude EA, and its particle size was much smaller than that of the crude EA. Evaluation in vitro demonstrated that the permeation rate of the purified EA was higher compared with the crude EA.

English

Tannase is an inducible extracellular enzyme produced by filamentous fungi, yeasts, and bacteria by solid-state fermentation (SSF) or submerged fermentation (SmF). Among the filamentous fungi, Aspergillus and Penicillium are recognized as the most efficient producers of tannase. The aims of this study were to evaluate the production of tannase under SSF by isolation from Aspergillus and Penicillium preserved in the Collection of Cultures Micoteca - URM (WDCM604); select the best enzyme producer, and use the crude extract to clarify mangaba and tamarind juices. The optimal conditions were determined by using the Placket-Burman Planning (PB) and response surface methodology (RSM). All tested crops produced activity between 2088.19 and 238.93 U/gds, and Aspergillus carneus URM5577 was the best producer. Through MSR, the best parameters for producing tannase were found to be 70 h of cultivation at pH 6.0, 7% tannic acid at 28°C and, as the response variable, 5449.31 activity U/gds. The optimum purification conditions were the molecular weight of PEG 8000 (g/mol), concentration of PEG 15% (w/w), 25% citrate (w/w), and pH 8.0. Its application in mangaba juice reduced the tannin content by 49.66% after 90 min and in tamarind by 51.82% at 120 min incubation at 37°C. Key words: Tannase, agroforestry waste, Aspergillus, Penicillium.

Purification, optimization and physicochemical properties of collagen from soft-shelled turtle calipash

The present work was to optimize the purification conditions for soft-shelled turtle (Pelodiscus sinensis) calipash collagen (STCC) isolated by pepsin and to explore collagen physicochemical properties for potential biomaterial applications. Single-factor test and orthogonal method L9 (34) were employed with the STCC recovery yield as indicator. The optimum purification conditions were obtained when NaCl concentration, collagen concentration and purification time were 2M, 8g/L, and 24h, respectively. Purified STCC were characterized by SDS-PAGE, UV scanning, FTIR, solubility, thermal behavior and amino acid analysis. The results showed that STCC contained high hydroxyproline content than that of other fishery skins, belonging to typical type I collagen in form of [α1(I)] 2α2(I). FTIR spectra of STCC were quite similar to other aquatic animals’ collagens. It has the lowest solubility at pH 6, and when NaCl concentration decreased from 2% to 6% (w/v), solubility dropped. The denaturation temperature (Td) and melting temperature (Tm) were 35.1°C and 105.14°C, respectively. Morphology of STCC depicted as regular and porous network structure by SEM. In general, the results suggested that turtle calipash can be exploited as alternatives to mammalian collagen and could also be used for biomedical applications as a potential new material.

Extraction and purification of lipase from Enterococcus faecium MTCC5695 by PEG/phosphate aqueous-two phase system (ATPS) and its biochemical characterization

Abstract Intracellular lipase from Enterococcus faecium MTCC5695 (MTCC5695), a lactic acid bacterium, grown at optimal conditions was subjected to purification and concentration using aqueous two-phase extraction system (ATPS). The partitioning behavior was studied for five different phase forming salts. Molecular weight of polyethylene glycol (PEG), concentration of PEG and phase forming salt, tie line length (TLL) and phase volume ratio were optimized for the purification of E. faecium lipase. Partitioning occurred towards bottom phase of the system containing sodium dihydrogen phosphate. The optimum conditions for purification were at PEG 8000, 41.24% TLL and 0.25 phase volume ratio. Activity recovery and purification factor achieved after ultrafiltration were 5.99% and 82.09%, respectively. In addition, enzyme characterization studies revealed that MTCC5695 produced an alkaline lipase. Molecular weight of the purified lipase was about 19.2 kDa; and, the purified lipase had optimal activity at pH 10.8 and 40 °C. Stability over different pH and temperature ranges along with the effect of variety of organic solvents is also reported. Studies involving group specific modifiers indicated the role of histidine, serine, carboxylate and tryptophan in the catalytic site, which is a characteristic feature of lipases.

Optimization of an Extraction and Purification Method of Total Flavonoids from Lycium barbarum Leaves

The content of total flavonoids as a evaluating factor and the extracting method of total flavonoids from Lycium barbarum leaves were investigated with an L9(34) orthogonal experiment.The optimum conditions were alcohol concentration 70%,ultrasonic time 50 min,ratio of liquor and material 30 ∶1,and ultrasonic wave power 250 W.The optimum conditions for purification were: addition of 4 mg/mL of the sample with pH 5.0,elution with 5.0 multiple column volume of 70% ethanol,sample flowing velocity 1 mL/min,and eluting velocity 1 mL/min.The extraction and purification methods were studied using adsorption capacity,desorption capacity,and recovery as the investigation parameters.Results showed that the method was superior to other methods due to its simplicity,low toxicity,and low variation coefficient.

Direct Purification of Pectinase from Mango (Mangifera Indica Cv. Chokanan) Peel Using a PEG/Salt-Based Aqueous Two Phase System

An Aqueous Two-Phase System (ATPS) was employed for the first time for the separation and purification of pectinase from mango (Mangifera Indica Cv. Chokanan) peel. The effects of different parameters such as molecular weight of the polymer (polyethylene glycol, 2,000–10,000), potassium phosphate composition (12–20%, w/w), system pH (6–9), and addition of different concentrations of neutral salts (0–8%, w/w) on partition behavior of pectinase were investigated. The partition coefficient of the enzyme was decreased by increasing the PEG molecular weight. Additionally, the phase composition showed a significant effect on purification factor and yield of the enzyme. Optimum conditions for purification of pectinase from mango peel were achieved in a 14% PEG 4000-14% potassium phosphate system using 3% (w/w) NaCl addition at pH 7.0. Based on this system, the purification factor of pectinase was increased to 13.2 with a high yield of (97.6%). Thus, this study proves that ATPS can be an inexpensive and effective method for partitioning of pectinase from mango peel.

Extraction of naringin from pomelo peels as dihydrochalcone's precursor

A new method for the separation of naringin from pomelo peels was investigated by using ultrasonic-assisted extraction and macroporous resin purification technology. The ultrasonic extraction efficiency was dependent on agent's concentration, ratio of sample and solvent and ultrasonic time. Several parameters of macroporous resin-purified process, including resin selection, initial concentration, concentration of eluted agent and pH, were optimized. The experimental results showed that the naringin content in the mature pomelo peels was 2.20% and purification rate of naringin was 77.26% under optimum conditions of purification. The structure of synthetic naringin dihydrochalcone was determined by a series of spectroscopic methods, such as UV, NMR and MS.

Ultrasonic activation of reagent purification of surface wastewaters from oil products

Reagent purification of water from oil contaminants can be intensified by preliminary ultrasonic short treatment of concentrated solutions. The major mechanism of the ultrasonic treatment of reagents is dispersion of coagulant and flocculant particles by cavitation. Based on the results of our studies, we chose the most suitable reagent and the optimum conditions of purification. The new acoustic reagent flotation technology is recommended for use in constructing waste disposal plants for surface water contaminated with oil products.