scholarly journals Subcritical Water Technology for Enhanced Extraction of Biochemical Compounds fromChlorella vulgaris

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
S. A. Awaluddin ◽  
Selvakumar Thiruvenkadam ◽  
Shamsul Izhar ◽  
Yoshida Hiroyuki ◽  
Michael K. Danquah ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Subcritical Water ◽  
Operating Conditions ◽  
Biofuel Production ◽  
Extraction Time ◽  
High Yield ◽  
Process Conditions ◽  
Subcritical Water Extraction ◽  
Total Carbohydrate ◽  
Microalgal Biomass

Subcritical water extraction (SWE) technology has been used for the extraction of active compounds from different biomass materials with low process cost, mild operating conditions, short process times, and environmental sustainability. With the limited application of the technology to microalgal biomass, this work investigates parametrically the potential of subcritical water for high-yield extraction of biochemicals such as carbohydrates and proteins from microalgal biomass. The SWE process was optimized using central composite design (CCD) under varying process conditions of temperature (180–374°C), extraction time (1–20 min), biomass particulate size (38–250 μm), and microalgal biomass loading (5–40 wt.%).Chlorella vulgarisused in this study shows high volatile matter (83.5 wt.%) and carbon content (47.11 wt.%), giving advantage as a feedstock for biofuel production. The results showed maximum total carbohydrate content and protein yields of 14.2 g/100 g and 31.2 g/100 g, respectively, achieved under the process conditions of 277°C, 5% of microalgal biomass loading, and 5 min extraction time. Statistical analysis revealed that, of all the parameters investigated, temperature is the most critical during SWE of microalgal biomass for protein and carbohydrate production.

scholarly journals Kinetic Study of Subcritical Water Extraction of Carbohydrate from Microalgae Nannochloropsis sp.

2021 ◽  
Vol 21 (1) ◽  
pp. 11
Author(s):  
Nur Baiti Listyaningrum ◽  
Muhammad Mufti Azis ◽  
Sarto Sarto ◽  
Anis Nurdhiani Rosdi ◽  
Mohd Razif Harun
Keyword(s):  
Kinetic Model ◽  
Subcritical Water ◽  
Maximum Yield ◽  
Operating Conditions ◽  
Water Extraction ◽  
Extraction Time ◽  
Process Conditions ◽  
Total Carbohydrate ◽  
Consecutive Reaction ◽  
Microalgal Biomass

Microalgae contain a significant amount of carbohydrates that can be converted further to produce valuable compounds. To extract carbohydrates from microalgae, sub-critical water extraction (SWE) is a viable and novel method. Compared to other existing chemical and biological extraction methods, SWE is more economical, effective, and efficient in terms of process conditions. This process uses high temperature and pressure of water at just below supercritical conditions to keep water at a liquid state. This study aims to investigate the factors that affect the extraction yield of carbohydrates from microalgae Nannochloropsis sp. using the SWE process. The extraction was carried out at a temperature of 160 – 320 oC, a duration of 5 – 25 min, and microalgal biomass loading of 5 - 25% w/v. The kinetics study was conducted in an extraction time of 5 – 25 min at 200 oC and 5% (w/v) biomass loading. A simplified kinetic model based on a consecutive reaction was used to describe carbohydrate production and decomposition via SWE. It was found that the maximum yield of total carbohydrate was 18.04 g/100 g which was obtained at 200 oC, 10 min, and 5% (w/v) microalgal biomass loading. The carbohydrate concentration was decreased as the temperature, extraction time and microalgal biomass loading increased. This result indicated that the SWE is a promising extraction method for carbohydrate recovery from microalgae, and the factors investigated here had a significant effect on the extraction process. The proposed kinetic model was also able to capture the experimental data well within the range of operating conditions studied in this work. 

A green strategy for obtaining anthraquinones from Rheum tanguticum by subcritical water

2020 ◽  
Vol 18 (1) ◽  
pp. 702-710
Author(s):  
Guoying Zhang ◽  
Xiaofeng Chi
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Subcritical Water ◽  
Extraction Time ◽  
High Yield ◽  
Extraction Temperature ◽  
Subcritical Water Extraction ◽  
Traditional Chinese Herbal Medicine ◽  
Anthraquinone Glycosides ◽  
Rheum Tanguticum

AbstractRheum tanguticum is a traditional Chinese herbal medicine, which contains abundant anthraquinones. In this study, anthraquinones were efficiently extracted from Rheum tanguticum by subcritical water extraction (SWE). The parameters of extraction time (33–67 min), temperature (100–200°C), and SW flow rate (1.4–4.6 mL/min) were optimized so as to achieve a high yield of the target product. A high yield of the total anthraquinones was achieved under the optimized SWE conditions of extraction time 54 min, extraction temperature 170°C, and the flow rate 2.0 mL/min. The comparison between the SWE and traditional extraction techniques implied that the SWE is an efficient and green alternative method for the extraction of anthraquinones. Four anthraquinone glycosides were purified from the SWE extract by high-speed counter-current chromatography and identified as emodin-1-O-β-D-glucoside, physcion-8-O-β-D-glucopyranoside, chrysophanol-1-O-β-D-glucoside, and chrysophanol-8-O-β-D-glucoside.

scholarly journals Recent Trends in Extraction Techniques for High Value Compounds from Algae as Food Additives

2018 ◽  
Vol 6 (8) ◽  
pp. 1008 ◽  
Author(s):  
Saniye Akyil ◽  
Işıl İlter ◽  
Mehmet Koç ◽  
Figen Ertekin
Keyword(s):  
Subcritical Water ◽  
Food Additives ◽  
Process Conditions ◽  
Extraction Techniques ◽  
Subcritical Water Extraction ◽  
Ultrasound Assisted Extraction ◽  
Algae Biomass ◽  
Green Extraction ◽  
Advantages And Disadvantages ◽  
Assisted Extraction

Algae have been considered as a source of high value bioactive compounds including pigments, lipids, fatty acids, polysaccharides, antioxidants and minerals. These compounds serve as a source of nutrition for both humans and animals and as additives in food production. Conventional solvent and/or green extraction techniques are mostly applied to extract these compounds from algae biomass. In this review, paper the most frequently used green extraction techniques such as supercritical fluid extraction, microwave assisted extraction, ultrasound-assisted extraction, pressurized liquid extraction, subcritical water extraction and pulsed electric field extraction were investigated in terms of their process conditions, applications, advantages and disadvantages.

scholarly journals Subcritical Water Extraction of Chestnut Bark and Optimization of Process Parameters

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2774 ◽  
Author(s):  
Tanja Gagić ◽  
Željko Knez ◽  
Mojca Škerget
Keyword(s):  
Process Parameters ◽  
Subcritical Water ◽  
Extraction Process ◽  
Extraction Yield ◽  
Water Extraction ◽  
Bark Extract ◽  
Total Phenol Content ◽  
Process Conditions ◽  
Subcritical Water Extraction ◽  
Influence Of Process Parameters

The aim of the work was the optimization of the subcritical water extraction process of chestnut bark using Box–Behnken response surface methodology. The influence of process parameters, such as temperature, extraction time and solvent-solid ratio, on extraction yield, yield of the main compounds, total phenol content, total tannin content and antioxidant activity has been investigated. The identified compounds were ellagic and gallic acids, ellagitannins (vescalagin, castalagin, 1-o-galloyl castalagin, vescalin and castalin), sugars (maltose, glucose, fructose and arabinose) and sugar derivatives (5-HMF, furfural and levulinic acid). Finally, the optimal process conditions for obtaining the bark extract highly rich in ellagic acid and with satisfactory levels of total phenols and total tannins have been determined.

Study on Subcritical Water Extraction of Flavonoids from Scutellaria baicalenses

2013 ◽  
Vol 662 ◽  
pp. 293-296 ◽  
Author(s):  
Yan Cheng ◽  
Jing Liu ◽  
Chang An Liu
Keyword(s):  
Subcritical Water ◽  
Extraction Yield ◽  
Water Extraction ◽  
Extraction Time ◽  
Particle Sizes ◽  
Extraction Temperature ◽  
Subcritical Water Extraction ◽  
Operation Conditions ◽  
Conventional Extraction ◽  
Total Extraction

The extraction of baicalin, baicalein, wogonin and wogonoside from Scutellaria Baicalenses was performed using subcritical water. The effects of key operation conditions by varying the temperature (110-160 °C), extraction time (10-90 min), water loadings (2.0-4.0 mL)and particle sizes (>20- <100 mesh) were evaluated. The highest extraction yields of baicalin and wogonoside were obtained at extraction temperature of 160 °C, extraction time of 60 min, water loadings of 4.0 mL and 60-100 mesh. The highest extraction yields of baicalein and wogonin were obtained at extraction temperature of 110 °C, extraction time of 10 min, water loadings of 4.0 mL and 60-100 mesh. The subcritical water extraction was compared with the conventional extraction method. The total extraction yield by SCWE was higher than those obtained using ethanol as the solvent.

Lipids Extraction from Wet and Unbroken Microalgae Chlorella vulgaris Using Subcritical Water

2019 ◽  
Vol 964 ◽  
pp. 103-108 ◽  
Author(s):  
Siti Zullaikah ◽  
Maria Christy P. Jessinia ◽  
Rinaldi ◽  
Medina Yasmin ◽  
M. Rachimoellah ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Chlorella Vulgaris ◽  
Subcritical Water ◽  
Dry Weight ◽  
High Water ◽  
Extraction Time ◽  
High Water Content ◽  
Subcritical Water Extraction ◽  
Factors Affecting ◽  
Polarity Index

Lipids extraction from wet and unbroken microalgae (Chlorella vulgaris) using subcritical water with aid of co-solvents has been investigated. Lipids extraction from wet and unbroken microalgae has a crucial role in order to eliminate dewatering and drying steps. Subcritical water is able to extract lipids from feedstock with high water content. This work was conducted to study several factors affecting in subcritical water extraction (SWE) from wet and unbroken microalgae. In this study, effect of co-solvent types (without co-solvent, chloroform, methanol, ethanol, ethyl acetate, and n-hexane) under subcritical water (microalgae = 5g (dry weight), moisture content= 94.12%, T= 160°C, P = 80 bar, t= 30 min), extraction time (15 min, 30 min, 1 h, 3 h, and 5 h), and temperature (160o C, 180o C and 200o C) on yield of lipids were investigated orderly. Yield of lipids obtained without co-solvent (water polarity index = 10.2) and with co-solvents of methanol (PI=5.1), ethanol (PI=5.2), chloroform (PI=4.1), ethyl acetate (PI=4.4), and n-hexane (PI=0.1) were 38.73%, 26.47%, 26.12%, 51.93%, 53.40%, and 25.59%, respectively compared to the yield of lipids extracted using Bligh and Dyer method. Ethyl acetate is solvent with moderate PI, therefore can extract more lipids that is also have moderate polarity. Ethyl acetate shows a good performance to extract lipids from wet and unbroken microalgae because ethyl acetate can extract broader range of lipids including neutral and polar lipids. This study also found that increasing of extraction time and temperature to extract lipids in subcritical water condition can increase yield of lipids.

scholarly journals Subcritical Water Extraction of Chlorella pyrenoidosa: Optimization through Response Surface Methodology

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Selvakumar Thiruvenkadam ◽  
Shamsul Izhar ◽  
Yoshida Hiroyuki ◽  
Razif Harun
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Subcritical Water ◽  
Chlorella Pyrenoidosa ◽  
Water Extraction ◽  
Biofuel Production ◽  
Oil Yield ◽  
Subcritical Water Extraction

Subcritical water extraction (SCW) was used to extract oil from Chlorella pyrenoidosa. The operational factors such as reaction temperature, reaction time, and biomass loading influence the oil yield during the extraction process. In this study, response surface methodology was employed to identify the desired extraction conditions for maximum oil yield. Experiments were carried out in batch reactors as per central composite design with three independent factors including reaction temperature (170, 220, 270, 320, and 370°C), reaction time (1, 5, 10, 15, and 20 min), and biomass loading (1, 3, 5, 10, and 15%). A maximum oil yield of 12.89 wt.% was obtained at 320°C and 15 min, with 3% biomass loading. Sequential model tests showed the good fit of experimental data to the second-order quadratic model. This study opens the great potential of SCW to extract algal oil for use in algal biofuel production.

scholarly journals Valorization of Yarrow (Achillea millefolium L.) By-Product through Application of Subcritical Water Extraction

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1878
Author(s):  
Jelena Vladić ◽  
Martina Jakovljević ◽  
Maja Molnar ◽  
Senka Vidović ◽  
Milan Tomić ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Bioactive Compounds ◽  
High Performance ◽  
Subcritical Water ◽  
Extraction Process ◽  
High Performance Liquid Chromatographic ◽  
Extraction Time ◽  
Achillea Millefolium ◽  
Subcritical Water Extraction ◽  
By Products

In the present study, valorization of yarrow (Achillea millefolium) by-product from the filter tea industry was investigated through the application of subcritical water for the extraction of bioactive compounds. The influence of different process parameters (temperature 120–200 °C, extraction time 10–30 min, and HCl concentration in extraction solvent 0–1.5%) on extract quality in terms of content of bioactive compounds and antioxidant activity was investigated. Optimal conditions of the extraction process (temperature 198 °C, extraction time 16.5 min, and without acidifer) were determined and, when applied, the most efficient exploitation of by-products is achieved, that is, attainment of extracts rich in total phenols and flavonoids and high antioxidant activity. In addition, by applying the high performance liquid chromatographic analysis, the content of chlorogenic acid was determined as well as the hydroxymethylfurfural content in obtained extracts. The results demonstrated that subcritical water can be successfully used for utilization of yarrow by-products for obtaining extracts rich in antioxidants.

scholarly journals Comparative Studies on Different Extraction Methods of Centella asiatica and Extracts Bioactive Compounds Effects on Antimicrobial Activities

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 457
Author(s):  
Farhana Nazira Idris ◽  
Masrina Mohd Nadzir
Keyword(s):  
Bioactive Compounds ◽  
Environmental Sustainability ◽  
Subcritical Water ◽  
Folk Medicine ◽  
Centella Asiatica ◽  
Extraction Methods ◽  
Antimicrobial Activities ◽  
Subcritical Water Extraction

The interest of consumers in using products containing phytochemicals derived from plants is growing day by day due to the shift of consumers’ preferences from convenience to environmental sustainability. One plant utilized in many products is Centella asiatica, a herb commonly used in folk medicine, health supplements, and beauty products. Extraction of bioactive compounds from C. asiatica was performed using conventional methods and modern methods (e.g., microwave or ultrasound-assisted and subcritical water extraction). This review summarizes the variety of methods used to extract active compounds from C. asiatica, their influence on the bioactive compounds and antimicrobial activity in vitro and in vivo, and the safety and toxicology of C. asiatica extract.

scholarly journals Investigation of operating conditions for soil remediation by subcritical water

2009 ◽  
Vol 15 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Saeed Soltanali ◽  
Shams Hagani ◽  
Venous Rouzbahani
Keyword(s):  
Extraction Efficiency ◽  
Subcritical Water ◽  
Data Interpretation ◽  
Operating Conditions ◽  
Hot Water ◽  
Extraction Time ◽  
Limiting Factor ◽  
Transfer Resistance ◽  
Water Flows ◽  
Rate Limiting

The aim of the present research is to investigate the application of subcritical water to naphthalene removal from soils. The extraction curves obtained show no clear patterns relating the operating conditions to the extraction time. This is mainly due to anomalies that occurred during some extraction runs. The analysis of the results shows an extraction time rather constant as function of the operating conditions (pressure, temperature, and mass flow). The extraction efficiency, on the other hand, is found to increase at higher hot water flows and lower temperatures, while no dependence is recorded from the pressure or the density. The data interpretation suggests that the film transfer resistance is the extraction rate limiting factor in the flow range considered. Finally, the relationships between the extraction efficiency and the operating conditions, together with the non-achievement of 100% efficiency, seems to confirm some authors' theory on the resistance to desorption due to the presence in the soil of 'resistant' and slowly desorbing fractions, constituted by immobile fluid in pores.

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