scholarly journals Laccase pretreatment for enhancing microwave-assisted alkaline extraction of hemicellulose from bagasse

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 931-942
Author(s):  
Jizhen Huang ◽  
Yuxin Liu ◽  
Bing Sun ◽  
Jiaoyang Li ◽  
Renfeng Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lignin Content ◽  
Structural Characteristics ◽  
Extraction Yield ◽  
Extraction Time ◽  
Alkaline Extraction ◽  
Optimum Conditions ◽  
Box Behnken Design ◽  
Microwave Assisted ◽  
Scanning Electron

Laccase pretreatment is a promising approach to degrade lignin polymer for enhanced hemicellulose extraction from bagasse. A Box-Behnken design was employed to optimize microwave-assisted alkaline extraction of hemicellulose with the aim of maximizing the hemicellulose extraction yield. The effect of laccase pretreatment on the structural characteristics of the bagasse hemicellulose was studied with scanning electron microscopy and the Brunauer-Emmett-Teller method. The results showed that the lignin content of the bagasse decreased by 7.9% and the specific surface area increased by 95.9% after pretreatment with 160 U/g laccase for 6 h. The hemicellulose extraction yield was 88.7% under the optimum conditions of 8% NaOH, 50 min, and 900 W. The interaction between the NaOH concentration and extraction time, and between the extraction time and microwave power significantly affected hemicellulose extraction from the bagasse. Overall, the laccase pretreatment was beneficial to extraction of hemicellulose from bagasse using a microwave-assisted alkaline solution.

Optimization of Microwave-Assisted Extraction of Polysaccharides from Panax japlcus Var

2013 ◽  
Vol 774-776 ◽  
pp. 919-922
Author(s):  
Xiao Song ◽  
Peng Zhao
Keyword(s):  
Microwave Power ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Raw Material ◽  
Extraction Time ◽  
Microwave Assisted Extraction ◽  
Box Behnken Design ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Optimum Extraction

Polysaccharide fromPanax japlcus var(PJVPs) was extracted with microwave-assisted (MAE). The effects of operating conditions, such as extraction time, ratio of water to raw material , and microwave power, on the extraction yield of PJVPs were studied through a Box-Behnken design (BBD). The optimum extraction conditions were as follows: extraction time 9.14 min, power 728.5 W and ratio of water to raw material 27.57ml/g. The yield of polysaccharide was 14.02 % based on the above mentioned conditions.

Optimization of Microwave-Assisted Extraction of Polysaccharides from Acanthopanax Obouatus Hoo

2012 ◽  
Vol 549 ◽  
pp. 504-507
Author(s):  
Xiao Rong Li ◽  
Peng Zhao
Keyword(s):  
Microwave Power ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Raw Material ◽  
Extraction Time ◽  
Microwave Assisted Extraction ◽  
Box Behnken Design ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Optimum Extraction

Polysaccharide from Acanthopanax obouatus Hoo(AHPs) was extracted with microwave-assisted(MAE). The effects of operating conditions, such as extraction time, ratio of water to raw material , and microwave power, on the extraction yield of AHPs were studied through a Box-Behnken design (BBD). The optimum extraction conditions were as follows: extraction time 13.5min, power 796 W and ratio of water to raw material 16.5ml/g. The yield of polysaccharide was 5.18% based on the above mentioned conditions.

scholarly journals Effects of Ultrasonic-Microwave-Assisted Technology on Hordein Extraction from Barley and Optimization of Process Parameters Using Response Surface Methodology

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xiao Guan ◽  
Lv Li ◽  
Jing Liu ◽  
Sen Li
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Microwave Power ◽  
Process Intensification ◽  
Extraction Yield ◽  
Extraction Time ◽  
Quadratic Model ◽  
Ultrasonic Power ◽  
Microwave Assisted ◽  
The Difference

We investigated the process intensification of ultrasonic-microwave-assisted technology for hordein extraction from barley. Response surface methodology was utilized to optimize the extraction conditions and to analyze the interaction between four selected variables: temperature, microwave power, ultrasonic power, and extraction time. The validated extraction yield of hordein reached 8.84% at 78°C, microwave power 298 W, and ultrasonic power 690 W after 20 min as optimum conditions. Compared with traditional water-bath extraction (4.7%), the ultrasonic-microwave-assisted technology effectively increased the hordein extraction yield and shortened the extraction time. According to the obtained quadratic model (R2 = 0.9457), ultrasonic power and extraction time were the first two significant factors. However, temperature limited the effects of other factors during extraction. SDS-PAGE and scanning electron microscopy were used to identify the hordein extract and to clarify the difference between the two hordein fractions extracted with new and traditional methods, respectively. Ultrasonic-microwave-assisted technology provided a new way to improve hordein extraction yield from barley and could be a good candidate for industrial application of process intensification.

scholarly journals DETERMINATION OF CHLORPYRIFOS IN LETTUCE (LACTUCA SATIVA L.) BY MICROWAVE-ASSISTED EXTRACTION COUPLED WITH HEADSPACE SINGLE DROP MICROEXTRACTION

2017 ◽  
Vol 9 (5) ◽  
pp. 248
Author(s):  
Naruephon Watthanaphap ◽  
Surapol Natakankitkul ◽  
Nuchnart Jonglaekha
Keyword(s):  
Ph Value ◽  
Limit Of Detection ◽  
Extraction Time ◽  
Microwave Assisted Extraction ◽  
Optimum Conditions ◽  
Single Drop ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Single Drop Microextraction ◽  
Limit Of Quantitation

Objective: The objective of this research was to improve the method of extracting pesticide residue from vegetable by using microwave-assisted extraction, headspace single drop microextraction (MAE-HS-SDME) and analysed by gas chromatograph-mass spectrometer (GC-MS).Methods: Microwave-assisted extraction (MAE) coupled with headspace single drop microextraction (HS-SDME) was used for extraction of chlorpyrifos insecticide residues in lettuce. The optimum conditions for obtaining efficient extraction have been tried; kind and quantity of solvent, extraction time, microwave irradiation power, pH value and the amount of salt added in the sample followed the method of Plackett–Burman. Optimum conditions for efficient analysis were evaluated by using a central composite design (CCD) combined with a response surface methodology (RSM).Results: The optimum extract conditions from CCD for the MAE-HS-SDME method were: using 1.5 µl of n-butyl acetate, 460 W of the microwave power, 4.5 min of the extraction time, no pH adjustment and no salt addition. Verification of the optimized experimental conditions showed that validation of the determination coefficient ranges from the concentrations of 0.01 to 0.10 mg/l, equal to 0.999; the percentages of variation coefficient were ranges from 4.6 to 7.7%; the recoveries ranges from 70.0 to 79.5%; limit of detection was 0.003 mg/kg and limit of quantitation was 0.01 mg/kg.Conclusion: In this study, the MAE-HS-SDME method coupled with GC-MS was found most suitable for chlorpyrifos analysis. The results obtained from analyzing chlorpyrifos in lettuce samples indicated that this method is rapid, simple, sensitive, reducible cost and safety for the analyst and the environment.

scholarly journals Optimization of Insoluble and Soluble Fibres Extraction fromAgave americanaL. Using Response Surface Methodology

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Amine Bouaziz ◽  
Manel Masmoudi ◽  
Amel Kamoun ◽  
Souhail Besbes
Keyword(s):  
Ionic Strength ◽  
Design Methodology ◽  
Extraction Yield ◽  
Agitation Speed ◽  
Optimum Conditions ◽  
Box Behnken Design ◽  
Factors Affecting ◽  
Soluble Fibre ◽  
Experimental Design Methodology ◽  
Significant Factors

Experimental design methodology was used to determine significant factors affecting the extraction yield of soluble and insoluble fibres fromAgave americanaL. and in second time to find optimum conditions leading to the highest yield. Results clearly indicated that the temperature, the powder to water (P/W) ratio, and the agitation speed were the most important factors influencing fibres extraction yield which increased with temperature, P/W ratio, and agitation speed. Ionic strength affected significantly soluble fibre extraction yield and was the most important factor among nonsignificant ones influencing insoluble fibres extraction yield. Then, a Box-Behnken design was carried out to maximise fibres extraction. Selected optimal conditions were temperature: 90°C; P/W ratio: 0.1625; agitation speed: 400 rpm; and ionic strength: 1.5 g/L. These conditions yielded 93.02% and 80.46% of insoluble and soluble fibres, respectively. Concentrates showed high fibres purity and good functional properties.

Examination of whewellite kidney stones by scanning electron microscopy and powder neutron diffraction techniques

2009 ◽  
Vol 42 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Michel Daudon ◽  
Dominique Bazin ◽  
Gilles André ◽  
Paul Jungers ◽  
Alain Cousson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Neutron Diffraction ◽  
Kidney Stones ◽  
Structural Characteristics ◽  
Calcium Oxalate Monohydrate ◽  
Atomic Scale ◽  
Mesoscopic Scale ◽  
Powder Neutron Diffraction ◽  
Scanning Electron

Kidney stones made of whewellite,i.e.calcium oxalate monohydrate, exhibit various morphological aspects. The crystalline structure of whewellite at the atomic scale was revisited through a single-crystal neutron study at room temperature using a four-circle automated diffractometer. The possible relationships between the various morphological types of whewellite stones and their structural characteristics were examined at the mesoscopic scale by the use of scanning electron microscopy and at the nanometric scale by powder neutron diffraction. All types of whewellite stones displayed a similar structure at the nanometric scale. However, significant differences were found at the mesoscopic scale. In particular, the crystallites in kidney stones resulting from a genetic hyperoxaluria exhibited a peculiar structure. There was a close relationship between stone morphology and crystallite organization at the mesoscopic level and the effectiveness of extracorporeal shockwave lithotripsy.

Kenaf Nanofiber/Polylactic Acid (PLA) Nanocomposite

2011 ◽  
Vol 471-472 ◽  
pp. 1095-1100 ◽  
Author(s):  
Agnes Surai Lasat ◽  
Abdan Khalina ◽  
Nor Azowa Ibrahim
Keyword(s):  
Electron Microscopy ◽  
Lignin Content ◽  
Tensile Modulus ◽  
Kenaf Fiber ◽  
Transmission Electron ◽  
Acetyl Group ◽  
Treated Fiber ◽  
High Pressure Homogenizer ◽  
Internal Mixer ◽  
Scanning Electron

Kenaf fiber was treated with alkaline to reduce lignin content and tested under Fourier transform infrared spectroscopy (FTIR). FTIR result showed that peak at 1146 cm-1 which is acetyl group of lignin was reduced in treated fiber while disappearing of carbonyl group in treated kenaf fiber at 1750cm-1 was significantly shown compared to untreated kenaf fiber. Treated fiber undergoes mechanical size decrement process by high pressure homogenizer with 500bar pressure and 60 passes. Transmission Electron microscopy (TEM) was used to determine size and distribution of fiber. Moreover, morphology of nanofiber was observed under scanning electron microscope (SEM). Nanofiber (3%, 5%, 8% and 10%) was mixed with PLA using internal mixer and then compressed with hot pressed to produce specimen for tensile test. Tensile strength and tensile modulus of nanocomposite with 10% of nanofiber increased by 30% and 85% respectively compared to pure PLA.

scholarly journals Optimization of process variables for phyllanthin extraction from Phyllanthus amarus leaves by supercritical fluid using a Box-Behnken experimental design followed by HPLC identification

2013 ◽  
Vol 63 (2) ◽  
pp. 193-207 ◽  
Author(s):  
Ajit A. Patil ◽  
Sachin S. Bhusari ◽  
Devanand B. Shinde ◽  
Pravin S. Wakte
Keyword(s):  
Carbon Dioxide ◽  
Hplc Analysis ◽  
Extraction Time ◽  
Phyllanthus Amarus ◽  
Process Variables ◽  
Optimum Conditions ◽  
Box Behnken Design ◽  
Assisted Extraction ◽  
Predicted Values ◽  
Good Agreement

The response surface methodology using the Box-Behnken design was established to describe supercritical carbon dioxide assisted extraction of phyllanthin from Phyllanthus amarus Schum and Thonn leaves prior to HPLC analysis. The effects of extraction pressure, temperature, modifier concentration and extraction time on the yield of phyllanthin were investigated. By solving the regression equation, the optimum conditions were as follows: extraction pressure 23.2 MPa, temperature 40 °C, methanol as modifier at a concentration of 10 % and time 90 min. Under these conditions, the phyllanthin yield was 12.83 ± 0.28 mg g-1, which was in good agreement with the predicted values. Modifier concentration and extraction time showed a significant effect on the phyllanthin yield.

scholarly journals Supercapacitors based on graphene/pseudocapacitive materials

2017 ◽  
Vol 82 (4) ◽  
pp. 411-416
Author(s):  
Denis Sacer ◽  
Magdalena Kralj ◽  
Suzana Sopcic ◽  
Milica Kosevic ◽  
Aleksandar Dekanski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Precursor Solution ◽  
Single Step ◽  
X Ray ◽  
Supercapacitor Application ◽  
Microwave Assisted ◽  
Simultaneous Synthesis ◽  
Insight Into ◽  
Scanning Electron

Composites of graphene and SnO2 were successfully prepared by a single step simultaneous synthesis of SnO2 and reduction of graphene oxide (GO). Three different compositions of precursor solution resulted in different composite materials containing graphene and SnO2. The reaction was realized by microwave-assisted hydrothermal synthesis. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) gave insight into the morphology and composition of the obtained materials. Good capacitive/pseudocapacitive properties of the obtained material suitable for supercapacitor application were registered by cyclic voltammetry, from where specific capacitance values up to 93 F g-1 were determined.

Microwave-Assisted Preparation of Cu2O Octahedral Microcrystals

2011 ◽  
Vol 284-286 ◽  
pp. 746-749
Author(s):  
Chong Hai Deng ◽  
Han Mei Hu ◽  
Ming Di Yang
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Growth Mechanism ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Microwave Assisted ◽  
Morphology And Structure ◽  
Scanning Electron

In this paper, we reported a facile microwave-assisted green chemical route to prepare pure, uniform, and monodispersed Cu2O octahedron wrapped by the {111} faces by using glucose as a reducing agent. X-ray diffraction (XRD), energy dispersive X-ray spectrometry(EDX) and field emission scanning electron microscopy (FESEM) were used to characterize the as-synthesized products. It was found that the morphology and structure of Cu2O crystals were greatly affected by the concentration of NaOH. A solid-solution-solid growth mechanism was possibly proposed on the basis of the comparative experimental results.

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