Alternative Extraction Method Research Articles

Casework direct kit as an alternative extraction method to enhance touch DNA samples analysis

Latent fingerprints are commonly found in crime scenes, and currently used in forensic analysis to obtain STR profiles from DNA recovered from finger contact. Analysis of STR profiles obtained from touch DNA has been very useful to elucidate crimes and the extraction method may be determinant for the recovery of genetic material collected from different surfaces. This study aimed to verify and compare the efficiency of two different extraction kits for processing touch DNA samples obtained from fingerprints deposited on computer keyboards, knife handles and exterior door handles and steering wheels of cars.One hundred and four experiments were conducted to simulate crime scenes and evaluate the efficiency of two extraction kits for touch DNA samples: the DNA IQ™ System and the Casework Direct Kit (both Promega Corporation). Each experiment was conducted with two individuals in order to obtain a mixture profile. The genetic material deposited was collected by double swab method (Sweet et al. 1997) and DNA quantification was conducted using Quantifiler Trio™ (ThermoFisher Scientific). Samples were amplified by PowerPlex® Fusion System kit (Promega).It was possible to obtain STR profiles for 32 (61.5%) out of the 52 extracted using DNA IQ and 51 (98.1%) out of the 52 extracted using the Casework Direct Kit. Samples extracted by DNA IQ had higher average of quantification values for long targets (>200bp) across all tested surfaces. That seems to be due to an incompatibility between the Quantifiler Trio and the Casework Direct Kit. Samples with positive quantification but without STR profile, as well as samples without quantification but with STR profiles were also observed.Statistical analysis showed that the Casework Direct Kit produced significantly more useful profiles than DNA IQ (p-value = 0.001), since these profiles had more STR markers with allelic correspondence to second donators present in the mixture.This study provides insights about the effect of different surfaces and extraction methods on recovery and generation of STR profiles. Limitations for the quantification step for these samples with a low quantity of DNA were highlighted as well. We concluded that the Casework Direct Kit was much more efficient for processing touch DNA samples than DNA IQ.

Application of Schiff bases derived from carboxymethylcellulose sodium in the separation of polysaccharides from kelp

AbstractBACKGROUNDA novel and rapid method for the separation and simultaneous extraction of two types of polysaccharides from kelp was developed using an ultrasonic‐assisted solid–liquid extraction method. Many polysaccharides obtained from diverse plant sources have important properties, such as anticancer, antioxidant and antitumor activities. Edible brown algae contain many bioactive compounds, including polysaccharides, vitamins and minerals. As the most common brown alga on the coastal areas of the Korean peninsula, kelp was selected to extract laminarin and fucoidan. Using ethanol as a solvent, the effects of ultrasonic‐assisted solid–liquid extraction on the extraction of polysaccharides from kelp, such as the extraction period, temperature, pH and mass:solvent ratio were investigated by high performance liquid chromatography.RESULTSCompared to traditional heating and microwave‐assisted extraction methods, ultrasonic‐assisted solid–liquid extraction produced higher extraction yields in a shorter time. The optimal conditions for the ultrasonic‐assisted solid–liquid extraction supporting the highest recoveries of the two polysaccharides were 40 °C, ethanol as a solvent at pH 6, 40 min and a 1:30 g mL−1 mass:solvent ratio. Under the optimal conditions, the recoveries of fucoidan and laminarin were 94.29% and 88.90%, respectively. The real quantities of fucoidan and laminarin extracted from kelp with synthesized carboxymethylcellulose sodium Schiff bases added to ethanol in the proposed method were 120.7 ± 0.26 and 45.3 ± 0.19 mg g−1, respectively.CONCLUSIONUltrasonic‐assisted solid–liquid extraction not only improved the recoveries of the extraction, but also was an eco‐friendly, efficient and promising alternative method for the simultaneous extraction of polysaccharides from kelp. © 2020 Society of Chemical Industry

Electronic Tongue Recognition with Feature Specificity Enhancement.

As a kind of intelligent instrument, an electronic tongue (E-tongue) realizes liquid analysis with an electrode-sensor array and certain machine learning methods. The large amplitude pulse voltammetry (LAPV) is a regular E-tongue type that prefers to collect a large amount of response data at a high sampling frequency within a short time. Therefore, a fast and effective feature extraction method is necessary for machine learning methods. Considering the fact that massive common-mode components (high correlated signals) in the sensor-array responses would depress the recognition performance of the machine learning models, we have proposed an alternative feature extraction method named feature specificity enhancement (FSE) for feature specificity enhancement and feature dimension reduction. The proposed FSE method highlights the specificity signals by eliminating the common mode signals on paired sensor responses. Meanwhile, the radial basis function is utilized to project the original features into a nonlinear space. Furthermore, we selected the kernel extreme learning machine (KELM) as the recognition part owing to its fast speed and excellent flexibility. Two datasets from LAPV E-tongues have been adopted for the evaluation of the machine-learning models. One is collected by a designed E-tongue for beverage identification and the other one is a public benchmark. For performance comparison, we introduced several machine-learning models consisting of different combinations of feature extraction and recognition methods. The experimental results show that the proposed FSE coupled with KELM demonstrates obvious superiority to other models in accuracy, time consumption and memory cost. Additionally, low parameter sensitivity of the proposed model has been demonstrated as well.

Novel ultrasound-assisted extraction of kefiran biomaterial, a prebiotic exopolysaccharide, and investigation of its physicochemical, antioxidant and antimicrobial properties

In recent years, ultrasound application as an alternative or auxiliary method for extraction of plant or microbial biopolymers has been considered by researchers. There is generally limited research on extraction of kefiran biomaterial. To the best of our knowledge, there is no information in the literature regarding the use of ultrasound for extraction of kefiran. In this regard, kefiran was extracted by hot water (HW), ultrasound (U) and hot water-ultrasound (HW + U) treatments and effects of the extraction methods were investigated on physicochemical, antioxidant and antimicrobial properties. Hybrid HW + U method significantly increased total sugars, protein, extraction yield, antioxidant activity and antimicrobial properties of kefiran compared to HW and U treatments. Kefiran samples produced by U treatment had the best color regarding the highest whiteness and lightness indices. Fourier transform infrared spectroscopy illustrated that there were no differences between the peaks of extracted samples with different treatments, confirming that the extraction methods did not influence the chemical structure of kefiran. Considering all the applied treatments, hybrid HW-U treatment generally demonstrated the best results in terms of various physicochemical, antioxidant, and antimicrobial characteristics of kefiran biopolymer and may be suggested for its commercial production for use in food and medicinal industries.

Applications of Dissimilatory Iron Reducing Bacteria (DIRB) for recovery of Ni and Co from low-grade lateritic nickel ore

Dissimilatory Iron Reducing Bacteria (DIRB) in specific has found wide range of application in bio-beneficiation for removal of iron impurities from different ores and in bioremediation for detoxification of heavy metals, hazardous pollutants, etc. Numerous research works have been reported for bio-beneficiation of kaolin, bauxite by IRB. This study aims at studying effect of anaerobic dissimilatory iron (III) reducing bacterial consortium on different phases of iron present in lateritic nickel ore. Such conversion in lateritic nickel ore is helpful in better recovery of sorbed metal values like Ni and Co by subsequent bioleaching or acid leaching. Over the past decade, the global demand-supply chain of nickel is constrained due to depletion of sulphidic nickel ores. However, with anticipated boom in electric vehicles (EVs), the forthcoming decade for battery demand is very bullish for nickel. Hence, there is an urgent need to extract nickel from lateritic nickel ores to meet its high demand. Application of conventional methods for nickel extraction from lateritic ores is challenging from metallurgical and technical viewpoint and requires high capital investments. There is ongoing search for alternative nickel extraction methods from lateritic ores to meet the high nickel demand loom. In India, nickel metal is concentrated in the Chromite overburden (COB) dumps of Sukinda Valley Jajpur, Odisha. The nickel metal is ingrained within the stable goethite matrix (oxidic mineral phase) which requires stringent actions (high energy and/or chemical attack) for its dissociation. 70% Ni and 81% Co was recovered on acid-leaching of DIRB-treated ore whereas only 54% Ni and 57% Co was recovered on acid leaching of untreated COB Hence, pre-treatment of COB with DIRB can enhance the recovery of nickel. Exploitation of competent indigenous microorganisms can thus formulate an eco-friendly approach for nickel extraction. This work discusses the various aspects of microbial application for nickel recovery from lateritic nickel ores.

Novel Method of Extraction for Radiocarbon Measurements of Atmospheric Carbon dioxide

ABSTRACTIn this paper, we present the first data from an alternative extraction method for atmospheric 14CO2 analysis, based on the direct trapping of whole air samples onto a molecular sieve zeolite (13X) trap, incorporated into a commercially available automated graphitization system. Results are presented for both inter-laboratory comparison samples and an in-house reference standard. The in-house reference was used to calculate the standard deviation of measurements (2.0‰). This newly developed method will facilitate faster sample processing and therefore lower cost per analysis, critical for scaling up such studies.

Intermittent and multi-stage fracture stimulation to optimise fracture propagation around a single injection well for enhanced in-situ leaching applications

Artificial fracture stimulation in host rock formations is a potential technique to improve the recovery efficiency of in-situ leaching mining applications, which is gradually creeping in as an alternative mining method for mineral extraction in low-grade ore deposits. In this study, we report two new methods of fracture stimulation by injecting a modified Soundless Cracking Demolition Agent (SCDA) into a target rock through an injection well as opposed to completely filling the injection well once with SCDA to produce a fracture. The first method, intermittent charging (where the injection well is charged intermittently with SCDA), was found to minimize the amount of SCDA used to fracture a finite rock mass. Experimental results suggest a 22.4% improvement in the efficiency (measured by the area of fracture produced per unit mass of SCDA) of fracturing for intermittent charging compared to continuous charging. Numerical simulations were carried out in conjunction using Particle Flow Code 3D (PFC3D) to understand the underlying mechanics of rock fragmentation during intermittent charging. The simulations reveal that during intermittent charging, an additional bending force is applied to the uncharged regions resulting in a supplementary fracture propagation, which improves fracturing efficiency. The second method, multi-stage charging (where SCDA is injected in two consecutive stages using the same injection well) increases the fracture density of a finite rock mass without the need for multiple injection wells. During stage two injection, the fracture density was increased, first by extending the fractures created during the first stage of injection, and second by creating micro hairline fractures around the first stage fractures. The laboratory experiments suggest that the methods introduced in this study can be used to optimize the fracture network generated in a host rock formation.

Comparison of the physicochemical and structural characteristics of enzymatic produced chitin and commercial chitin

White shrimp (Litopenaeus vannamei) waste is a good source of chitin. However, the chemical chitin extraction generates a large amount of environmental-pollution and increases partial deacetylation of chitin. Therefore, the use of biological extraction is an interesting alternative. This study aimed to isolate chitin by Trypsin and Ficin with/without sodium-metabisulfite and investigate their properties as compared to commercial chitin. Shell demineralization and deproteinization were done by lactic-acid and proteolytic-enzyme (0.1–0.05%w/w). The enzymatic deproteinized shells were subjected to mild-alkali treatment (0–2% NaOH; 60 °C and 30 min). After demineralization the ash content was decreased to ~1.1%. The combination of enzymatic and mild chemical treatments exhibited the 92% deproteinization. The enzymatic deproteinization was higher in presence of sodium-metabisulphite (p > 0.05). The CI of enzymatic-chitin was more than commercial-chitin (p < 0.05). Therefore, a smooth with high molecular packing microstructure was observed in enzymatic- chitins. The DA% of enzymatic chitins (81–83%) were higher than chemical (p < 0.05). The chitins with DA between 70 and 90% and low protein content, is considered as good final products. Therefore, the enzyme-assisted chitin extraction generated the high grade chitin under mild and semi-ecofriendly conditions. This method is a promising alternative method for chemical extraction which can retain the native microstructure of chitin.

Simultaneous production of lignocellulolytic enzymes and extraction of antioxidant compounds by solid-state fermentation of agro-industrial wastes

In recent years, the interest to find alternative extraction methods has increased. Extraction of natural phenolics by enzymes produced during solid-state fermentation (SSF) is a useful and novel technique environmentally friendly. On the other hand, agro-industrial wastes are an excellent source of natural antioxidants as phenolics.The aim of the work was to evaluate the increase of antioxidant compounds extraction from agro-industrial wastes after SSF and to relate it to the production of lignocellulolytic enzymes. Several filamentous fungi were evaluated as candidates to increase the extraction of antioxidant compounds by solid-state fermentation of wineries, olive mill and brewery wastes. Fermented and unfermented agro-industrial wastes were extracted with water and lignocellulolytic enzymes, total phenolic compounds and antioxidant activity were determined in the extract. The maximum xylanase and cellulase activities were achieved by A. ibericus strains using brewer´s spent grain (BSG) as substrate and ranged from 300 to 313 U xylanase/g and 51–62 U cellulase/g. The best producer of β-glucosidase was A. niger CECT2088 using BSG as substrate (94 ± 4 U/g). The results of extraction of phenolic compounds revealed a higher extraction by SSF in olive mill wastes followed by winery wastes. In the same form, the maximum increase of antioxidant activity was achieved by SSF of exhausted olive pomace by Rhizopus oryzae MUM 10.260, increasing 12.9-fold in relation to unfermented waste. In addition, the production of enzymes, the extraction of phenolic compounds and the increase of antioxidant activity were related by principal component analysis. The first component grouped the BSG along with maximum enzymes production, the second component related positively the production of enzymes and the extraction of phenolic compounds and the increase of antioxidant activity.SSF proved to be an innovative environmentally friendly process that can improve the extraction of antioxidant compounds and simultaneously to produce lignocellulolytic enzymes from different agro-industrial wastes.

Use of Aqueous Two-Phase and Three-Phase Partitioning Systems for Purification of Lipase Obtained in Solid-State Fermentation by Rhizopus arrhizus

Background: Purification of enzymes by conventional methods such as precipitation and chromatographic techniques is a costly and time-consuming procedure and may lead to low yields of enzyme activity. Alternative liquid-liquid extraction methods such as Aqueous Two-Phase Systems (ATPS) and Three Phase Partitioning (TPP) are characterized by the high enzyme yields and purification degree. Objective: The objective of this study was the application of partitioning systems ATPS and TPP for purification of lipase produced in solid-state fermentation by Rhizopus arrhizus. Methods: ATPS and TPP were used for purification of lipase, obtained by solid state cultivation of Rhizopus arrhizus. Results: Lipase was isolated with PEG4000/potassium sodium tartrate ATPS and the effect of the system composition, including PEG 4000 and potassium sodium tartrate concentrations on lipase partitioning was studied. When using 30% PEG4000/21% potassium sodium tartrate, lipase was distributed in the top phase, and the highest recovery yield of 217% and purification fold of 6.1 were achieved. It was found that at PEG4000 concentration of or higher than 15%, the enzyme was present in the top polymer-rich phase with a partitioning yield of over 90%. Upon application of TPP for lipase isolation, the effect of t-butanol concentration, ammonium sulfate concentration and pH on enzyme partitioning was investigated. The highest lipase recovery yield of 71% and 19.1-fold purification were achieved in the interfacial phase in the presence of 30% ammonium sulfate saturation with 1.0:0.5 crude extract/t-butanol ratio at pH 7 in a single step. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymographic analysis showed significant purification of lipase by TPP and the presence of two multiple forms of the enzyme. Conclusion: ATPS (PEG4000/ Potassium sodium tartrate) and TPP (1.0:0.5 crude extract/t-butanol ratio, 30% ammonium sulfate saturation, pH 7) proved to be rapid methods for the isolation and purification of lipase and they can be used in downstream processing for industrial preparation of the enzyme.

Subcritical Fluid Extraction of Antioxidant Phenolic Compounds from Pistachio (Pistacia vera L.) Nuts: Experiments, Modeling, and Optimization.

A process to obtain phenolic compounds with antioxidant properties from pistachio nuts using water/ethanol mixture under high temperature and pressure conditions was carried out. To optimize extraction conditions and antioxidant activity of bioactive compounds, theoretical models were scanned against experimental data. Phenolic profile was dominated by several flavonoids and gallic acid derivatives. A fitted model for phenolic compounds extraction presented a maximum predicted value under the following conditions: 220 °C extraction temperature, 6.5MPa pressure, and 50% ethanol. Beneath these conditions, phenolic extracts gave the highest radical scavenging capacity, similar to that reached by using commercial antioxidants. A mathematical model, namely two-site desorption kinetic model, showed to be suitable for the description of extraction kinetics under the optimal operation conditions. Overall, the process described in this study shows a potential alternative method for extraction of pistachio bioactive compounds. PRACTICAL APPLICATION: Pistachio nuts are known to contain a vast array of phenolic and polyphenolic substances having strong antioxidant properties. Currently, the use of natural antioxidants in the food industry has increased, in consequence there is a growing interest in improving the extraction processes using GRAS (general recognize as safe) solvents. This study describes a safe, inexpensive, and short-time method (subcritical fluid extraction) to obtain antioxidant extracts from defatted pistachio nuts. This type of process may be adapted toward applications at industrial scale.

Constrained stability of conservative static equilibrium

Modelling of static structural stability problems is considered. Focus is set on problems where passive physical constraints affect the response to applied forces, and where more than one free parameter describes the setting. The existence of vibration frequencies at equilibrium states is investigated, as an indication of stability. The relevant Jacobian matrix is developed, with an emphasis on the necessity to formulate the constraint equations from an energy form in a conservative problem. The corresponding mass matrix is introduced, with zero mass contribution from constraint equations. Three different forms of the relevant Jacobians are considered, and alternative methods for the eigenvalue extraction given. Stability is discussed in a context of generalized equilibrium problems, where auxiliary parameters and equations can be included in a continuation setting. Examples show the formulation, implementation and interpretation of stability.

Bacterial hyaluronic acid production through an alternative extraction method and its characterization

AbstractBACKGROUNDIn this study, hyaluronic acid (HA) was produced using Streptococcus equi ssp. equi via an optimized Central Composite Design process, with purification by an alternative extraction method. Determinations of molecular weight, cytotoxicity, viscosity; proton nuclear magnetic resonance (H‐NMR) and Fourier transform infrared‐attenuated total reflection (FTIR‐ATR) analyses were provided.RESULTSThe HA yield obtained was up to c. 12 g L−1 under the reaction conditions of pH 7.8, 33 °C incubation temperature, 24 h incubation time and 187 rpm agitation rate. According to gel permeation chromatography results, HA has an average molecular weight of 79 416 Da. FTIR‐ATR analysis showed that the spectrum of the standard HA sample overlapped with the spectrum obtained from this study.CONCLUSIONIn this study, higher titer production of HA was obtained with a simple and economical sequential process. Additionally, the results indicate that the HA produced is an appropriate biomaterial for medical applications. © 2019 Society of Chemical Industry

Effect of high-pressure homogenization on the extraction of sulforaphane from broccoli (Brassica oleracea) seeds

High-pressure homogenization (HPH) has the potential to improve the exaction yield of bioactive compound from food and food waste. This study investigated the use of HPH or microfluidization as an alternative assisted method for sulforaphane extraction from raw broccoli seeds. The mean particle size, morphological characteristics, and extraction yields of all samples processed at different HPH pressure levels (3000-23,000 psi) and passes (1–5) were examined. After HPH, the particle size of broccoli seeds was reduced 2–10 times and the particle size distribution pattern also changed from bimodal to unimodal with increasing pressures and number of passes. The highest sulforaphane content obtained with HPH at 5000 psi and 5 passes was 2199 μg sulforaphane/g broccoli seeds, which is 3 times more than the control one. Particular interest was given to the relationship between sulforaphane yield and particle size. Generally, the extraction yield increased with decreasing particle size; however, excessive size reduction did not necessarily result in significant increase in sulforaphane content. In addition, the pressure is not the higher the better (<8000 psi, 55 MPa). Scanning electron morphology (SEM) also confirmed that cell rupture and cell walls breakage occurred during the HPH process.

Extraction of potato cyst nematodes from soil samples: Cobb’s decanting and sieving method vs. Fenwick’s method

Potato cyst nematodes are a threat to several agricultural crops around the world with some species considered quarantine pests and subjected to strict regulatory measures in many countries. Usually, cysts nematodes co-exist in the soil with other species of plant-parasitic nematodes, so, a time and cost-efficient extraction technique becomes of primary importance. The ideal extraction method should be able to obtain cysts as well as detecting the presence of other motile plant-parasitic nematodes with a potential impact on potato farming (such as Meloidogyne sp. and Pratylenchus sp.). In recent years, studies have been carried out to test the efficiency of various methods of nematode extraction but few results have been published. Therefore, to test if a method that extracts simultaneously cysts and motile nematodes can be used instead of the reference method that extracts cysts only, the efficiency of Cobb’s decanting and sieving technique was compared to Fenwick’s technique. As a result, in the 74 samples evaluated, a greater number of cysts were extracted from 24 samples using Fenwick’s method and from 11 samples employing Cobb’s decanting and sieving technique. The statistics results showed a significance level of 0,05 using Fenwick’s can allowing to conclude that this method is much more efficient than Cobb’s decanting and sieving technique, and confirming it should not be replaced by alternative methods for cysts extraction.

Mass transfer intensification in bioactive compounds recovery by alternative extraction methods: effects of solvent

&lt;p&gt;Recently, the exploration of new alternatives to common organic solvents in combination with non-conventional energy sources is a subject of intense research and development as tools for green extraction of plant-derived natural products. This paper deals with the use of low frequency ultrasound (100 W, 32 kHz) and pulsed electrical fields (0.86 kV cm-1, 13 Hz) to raise the efficiency of the extraction of selected plant species rich in valuable phenolic compounds.Four types of natural deep eutectic solvents were applied for the ultrasound-assisted extraction of silymarin from milk thistle among which a choline-chloride-based mixture with glycerol was proved to be the most promising one. Additionally, the usage of high ultrasound power significantly increased the concentration of sylimarin as compared to traditional ethanol extraction, generating rapidly for 10 min considerable temperature rise as a side effect under non-cooling conditions. The application of PEF as a pre-treatment for 0.8 s to the extraction allowed reducing the ethanol percentage in the ethanol/water mixtures giving comparable phenolic yields, without any, or very little, increase in temperature. As such, optimized power intensity in conjunction with appropriate solvent system provides a potential to improve the release of thermally unstable bioactive compounds under mild processing conditions.&lt;/p&gt;

Composition Analysis of Essential Oil from Melaleuca bracteata Leaves Using Ultrasound-assisted Extraction and its Antioxidative and Antimicrobial Activities

To extract essential oil from Melaleuca bracteata leaves without thermal degradation, ultrasound-assisted extraction (UAE) was developed and optimized using a response surface method (RSM) based on the Box-Behnken design (BBD). Under the optimized extraction conditions, a higher essential oil yield of 4.55% was achieved in comparison to that of 1.02% via the conventional hydrodistillation extraction method, which suggested that UAE could be used as an alternative and efficient extraction method for the essential oil from M. bracteata leaves. Furthermore, the composition of the essential oil extract was analyzed by gas chromatography-mass spectrometry. The results showed that 42 constituents, including methyl eugenol (86.5%), methyl cinnamate (4.33%), 3,4,5-trimethoxybenzoic acid, methyl ester (1.77%), and germacrene D (1.24%) were identified in the essential oil of M. bracteata leaves. The essential oil showed strong 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and reducing property. Additionally, remarkable bacteriostatic activity was observed against the tested pathogens, including Chromobacterium violaceum ATCC31532, Pseudomonas aeruginosa PAO1, Serratia marcescens MG1, and Serratia marcescens H30. These results indicated that the essential oil from M. bracteata leaves had potential applications due to its antioxidative and antimicrobial activities.

Assessing and refining the satellite-derived massive green macro-algal coverage in the Yellow Sea with high resolution images

During over the past 10 years, the massive green macro-algal bloom has regularly occurred in the Yellow Sea, the spatial coverage of which is mainly derived by the remote sensing community from satellite images with moderate/low resolution (30-m–1000-m), such as the 250-m-resolution MODIS (Moderate Resolution Imaging Spectroradiometer). In this paper, the MODIS estimates are compared for the first time with the concurrent high resolution (3-m) airborne Synthetic Aperture Radar (SAR) data. We find that the MODIS results are overestimated by more than a factor of 3 when each algae pixel is assumed to be pure (i.e. 100% algae cover), whereas the overestimation is significantly reduced to 1.14 when the pure pixel assumption is abandoned and the genuine (fractional) algae coverage is derived with the linear pixel un-mixing method. These results, together with the re-sampling processing of the high resolution images, indicate that the mixed pixel effect, that is inherent with images with moderate and low resolutions, is the key factor for the satellite extraction of the macro-algae coverage, and these findings are further confirmed by the satellite data with different resolutions. Besides, significant correlations (R2 > 0.9) are found between the macro-algae coverage from 3-m resolution SAR images and those from concurrent satellite images with various resolutions (30-m–1000-m) under the pure pixel assumption, which provides an alternative statistics-based method (in addition to the linear pixel un-mixing) for the accurate macro-algae coverage extraction from satellite images with coarse resolution (e.g. HJ-1 CCD, AQUA MODIS, COMS GOCI). This new method is independently validated with high resolution optical images, and applied to derive the annual maxima of the massive green macro-algal bloom areas (fractional coverage) in the Yellow Sea from 2007 to 2016, which ranges from 45.6 to 732.9-km2 with an average of 247.9 ± 199.3-km2.

Kinerja Ekstraksi Minyak Akar Wangi dengan Metode Ultrasonikasi dan Soxhletasi

This study aims to extract vetiver oil by alternative extraction methods, namely ultrasonic extraction and soxhlet extraction. The performance of both extraction methods is compared based on the effect of extraction operation conditions with yield and quality parameters of vetiver oil produced. The quality of vetiver oil was determined and compared with SNI 06- 2386-2006. The specified quality parameters are color, odor, density, refractive index, and solubility in 95% ethanol. The composition of compounds in vetiver oil was identified by GC-MS method (Gas Chromatography-Mass Spectrometry). The results showed that ultrasonic extraction performed more effectively than soxhlet extraction. The ultrasonic extraction and soxhlet extraction gave an oil yield of 3.98±0.58% and 3.95±0.81%. In the extraction with ultrasonic aid performed in extraction time about 3/10 times shorter and solvent consumption about 2/3 times less compared with soxhlet extraction. In terms of quality, vetiver oil from ultrasonic extraction has eligible with the quality standard according to SNI 06-2386-2006 based on the test parameter. The GC-MS showed that vetiver oil from ultrasonic extraction composed of the mayor compounds of khusenic acid (36.40%), zierone (13.89%), nootkatone (1.92%), γ-selinene (1.57%), α-vetivone (1.43%), isolongifolene (1.32%), δ-cadinene (0.86%), and khusimene (0.64%).

Supercritical Carbon Dioxide Extraction of Selected Herbal Leaves: An Overview

Supercritical fluid extraction of carbon dioxide (SC-CO2) is one of new alternative extraction method that has been widely used to isolate bioactive components from variety of plant materials. The method was proved to be clean and safe, compatible for the extraction of edible products such as spices, food additives, medicines and nutritional supplement products compared to traditional extraction techniques such as solvent extraction, hydro distillation and steam distillation. The SC-CO2 extraction was known as highly influenced by its process parameter such as temperature and pressure for obtaining maximum yield. Therefore, a clear review on the optimum range of temperature and pressure for herbal leaves extraction using SC-CO2 is necessary for future reference. The aim of this work is to analyze the effect of temperature and pressure of SC-CO2 process without modifier on extraction yield of some selected herbal leaves i.e clubmoss, drumstick leaves, kratom leaves, mallee and myrtle leaves. The values of investigated parameters were; pressure from 8.9 to 50 MPa and temperature from 35 to 80°C. The results showed that the highest extraction yields were obtained when the pressure and temperature were above 30 MPa and 40°C. The interaction between pressure and temperature for SC-CO2 extraction of plant leaves are crucial since the values cannot be very high or very low in order to preserve the quality of the extracts.