scholarly journals Spruce Bark—A Source of Polyphenolic Compounds: Optimizing the Operating Conditions of Supercritical Carbon Dioxide Extraction

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4049 ◽  
Author(s):  
Petra Strižincová ◽  
Aleš Ház ◽  
Zuzana Burčová ◽  
Jozef Feranc ◽  
František Kreps ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Total Phenolics ◽  
Extraction Process ◽  
Solvent Mixture ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Bark Extract ◽  
Water Mixture ◽  
Spruce Bark ◽  
Phenolics Content

The present study described the optimization of the extraction process with carbon dioxide in supercritical state for obtaining extractives, especially polyphenols from softwood bark, Norway spruce (Picea abies (L.) Karst.). Using a full 23 factorial design of experiments, the effect of varying the working parameters on the yield of extractives was studied for the following ranges: temperature 40–100 °C, pressure 1050–9000 psi (7.2–62 MPa), and concentration of EtOH/water co-solvent mixture 40–96.6%. In addition, total phenolics content and the antioxidant capacity of the spruce bark extract were determined. The optimum operating conditions for the yield of extractives were identified as 73 °C, 6465 psi (44.5 MPa), and 58% EtOH/water cosolvent concentration for a yield of 8.92%. The optimum conditions for achieving a total phenolics content of 13.89 mg gallic acid equivalent (GAE)/g dry extract were determined as: 45 °C, 1050 psi (7.2 MPa), and 96.6% EtOH/water mixture.

Exergy Analysis of a Combined Power and Refrigeration Thermodynamic Cycle Driven by a Solar Heat Source

2003 ◽  
Vol 125 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Afif Akel Hasan ◽  
D. Y. Goswami
Keyword(s):  
Heat Source ◽  
Exergy Analysis ◽  
Thermodynamic Cycle ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Water Mixture ◽  
Exergy Destruction ◽  
Ammonia Water ◽  
Solar Heat

Exergy thermodynamics is employed to analyze a binary ammonia water mixture thermodynamic cycle that produces both power and refrigeration. The analysis includes exergy destruction for each component in the cycle as well as the first law and exergy efficiencies of the cycle. The optimum operating conditions are established by maximizing the cycle exergy efficiency for the case of a solar heat source. Performance of the cycle over a range of heat source temperatures of 320–460°K was investigated. It is found that increasing the heat source temperature does not necessarily produce higher exergy efficiency, as is the case for first law efficiency. The largest exergy destruction occurs in the absorber, while little exergy destruction takes place in the boiler.

scholarly journals Response Surface Optimization of Supercritical Carbon Dioxide Extraction of Tea Polyphenols from Green Tea Scraps

2019 ◽  
Vol 102 (2) ◽  
pp. 451-456 ◽  
Author(s):  
Weifang Wang ◽  
Sai Han ◽  
Xianjun Zha ◽  
Jiangrui Cheng ◽  
Junying Song ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Response Surface ◽  
Green Tea ◽  
Maximum Yield ◽  
Extraction Process ◽  
Operating Conditions ◽  
Tea Polyphenols ◽  
Optimal Conditions ◽  
Key Factors

Abstract Background: The green tea scraps are the waste materials during the process of green tea production, and it is significant to extractvaluable tea polyphenols (TP) for reuse. Objective: The objective of this study was to extract valuable TP from green tea scraps, and the extraction conditions were optimized to obtain maximum yield of TP. Methods: The TPwere extracted by supercritical carbon dioxide (SC-CO2) with 65% (v/v) aqueous ethanol solution as cosolvent. The content of TP was determinedwith the Folin-Ciocalteu method. The key factors ofthe extraction process, including temperature (313.15–323.15 K), pressure (20–30 Mpa), and amount of cosolvent (50–150 mL) were optimized by response surface methodology (RSM). Results: These key factors showed the extremely complex effects on the extraction yield of TP. A second-order polynomial mathematical modelwasdeveloped for the response with high R-squared value (R2 = 0.9946) and used to predict the optimal conditions (i.e., temperature of 322.15 K, pressure of 23.60MPa, and amount of cosolvent of 150 mL). The verification experiments showed that the maximum yield ofTP was 23.07 ± 0.82% under the optimal conditions, which was in good agreement with the predicted value. Conclusions: TP can be successfully extracted from green tea scraps by SC-CO2, and RSM could be used to optimize the extraction process. Highlights: SC-CO2 extraction of TP from green tea scraps was developed. The operating conditions, including pressure, temperature, and amount of cosolvent, were optimized. RSM could successfully predict the optimal operating conditions.

scholarly journals Antioxidant Activity of Extract from Ultrasonic-Assisted Extraction of Durian Peels

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Bambang Kunarto ◽  
Ely Yuniarti Sani
Keyword(s):  
Antioxidant Activity ◽  
Total Phenolics ◽  
Extraction Process ◽  
Extraction Time ◽  
Total Flavonoids ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Total Flavonoids Content ◽  
Phenolics Content ◽  
Ultrasonic Assisted Extraction

The increase in durian production results in the accumulation of durian peel waste. The bioactive component of durian peel has the potential to be used as an antioxidant. Thus, there is a need to carry out an extraction process to obtain  bioactive compounds from durian peel. However, conventional extraction methods cause damage to phenolic compounds due to oxidation, hydrolysis and ionization reactions during the extraction process. Therefore, durian peel extraction was carried out using ultrasonic assisted extraction method (UAE) in this study. The purpose of this study was to investigate the effect of varying ratios of durian peel to ethanol solvents and extraction time on the yield, total phenolics content, total flavonoids content and antioxidant activity. The results of the research data were analyzed using a two-factor completely randomized design, which included variations of the ratio of durian peel to ethanol solvents and extraction time The Duncan’s New Multiple Range Test (DNMRT) was carried out as a follow up test to determine the differences in each treatment at a significance level of 0.05. The results showed that the best treatment for peel extraction using ultrasonic assisted extraction was a 1: 9 ratio of durian peel to ethanol at an extraction time of 20 minutes. The extraction of durian peel under this condition gave the highest yield of 12.77 ± 0.16%, antioxidant activity (IC50) of 38.33 ± 0.12 ppm, total phenolic content of 63.30 ± 0.08 mgGAE / g and total flavonoids content of 47.53 ± 0.48 mgQE / g. In addition, total phenolics content and total flavonoid content showed a strong correlation to the antioxidant activity of durian peel extract.

Potential of Five-Leaved Chaste Tree (Vitex negundo L.) Leaves as Source of Natural Dye from Supercritical Carbon Dioxide (SC-CO2) Extraction

2013 ◽  
Vol 594-595 ◽  
pp. 207-213
Author(s):  
T.A.T. Mohd ◽  
Nur Hashimah Alias ◽  
Nurul Aimi Ghazali ◽  
A. Azizi ◽  
Idris S. Adeib ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Low Cost ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Synthetic Dyes ◽  
Vitex Negundo ◽  
Optimum Operating Condition ◽  
Supercritical Carbon

Natural dyes represent a sustainable source of colorants, which are low cost and safer than synthetic dyes, concerning human health. The purpose of this study is to extract Vitex negundo L. leaves using supercritical carbon dioxide extraction and to identify the extracts potential as a dye. The extraction process has been conducted at different operating conditions by varying temperature from 40 to 65°C with an increment of 5°C at 20, 25, and 30 MPa within 60 minutes constant time. The extracts obtained at different conditions were analyzed using Gas Chromatography Mass Spectrometer (GC-MS) to determine the chemical compounds present. Increase of temperature increased the extraction yield, but further increasing the temperature above 50°C has reduced the yield. The effect of pressure gave two different patterns, in which the first one showed the yield kept increasing with pressure (20 to 30 MPa) at 40, 45, 50, and 55°C. The second pattern showed sudden reduction of yield above 25 MPa at another two higher temperatures. The highest extraction yield (13.94 mg/g) was obtained at 30 MPa and 50°C which considered as optimum operating condition. GC-MS analysis showed the presence of several phytochemicals including some flavonoid compounds, which are potential sources of dye.

scholarly journals Influence of Elicitation and Germination Conditions on Biological Activity of Wheat Sprouts

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Dariusz Dziki ◽  
Urszula Gawlik-Dziki ◽  
Monika Kordowska-Wiater ◽  
Monika Domań-Pytka
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Biological Activity ◽  
Total Phenolics ◽  
Aerobic Bacteria ◽  
Bark Extract ◽  
Wheat Cultivars ◽  
Germination Temperature ◽  
Microbiological Examination ◽  
Phenolics Content ◽  
Lower Temperature

The influence of elicitation, time, and temperature of germination on the biological activity of wheat sprouts was studied. The total phenolics content (TPC), antioxidant activity (AA), and microbiological purity of seeds of three wheat cultivars elicited withSaccharomyces cerevisiae(Y) andSalix daphnoidesbark extracts (W) and their mixture (1 : 1) germinated in different conditions were studied. The increase of germination time caused an increase the TPC and AA for all tested wheat cultivars. Germination temperature also influenced these parameters. Generally the highest values in TPC were obtained for sprouts germinated at 20°C. This tendency was found for all tested wheat cultivars. The highest values of TPC and AA were obtained after elicitation byS. daphnoidesbark extract. The results of microbiological examination showed that generally for seeds germinated at lower temperature (15°C and 20°C) and during 2 and 4 days the molds were not detected and the levels of aerobic bacteria did not exceed the usually accepted limits. Taking into account both biological activity and microbiological purity of samples the best quality sprouts were in the most cases obtained for wheat germinated during four days at 20°C and elicited by W.

Parametric Study of a Combined Power and Cooling Thermodynamic Cycle for Low Temperature Heat Sources

2009 ◽  
Author(s):  
Ricardo Vasquez Padilla ◽  
Gokmen Demirkaya ◽  
D. Yogi Goswami ◽  
Elias L. Stefanakos
Keyword(s):  
Low Temperature ◽  
Parametric Study ◽  
Waste Heat ◽  
Ammonia Concentration ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Working Fluid ◽  
Basic Solution ◽  
Water Mixture

A combined power/cooling cycle, which combines the Rankine and absorption refrigeration cycles, uses ammonia-water mixture as a working fluid and produces power and refrigeration while power is the primary goal. This cycle, also known as the Goswami Cycle, can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using low temperature sources such as geothermal and solar energy. This paper presents a parametric analysis of the combined cycle. Parametric study of the cycle was carried out in the commercial software Chemcad 6.1. The thermodynamic property data used in simulations were validated with experimental data. Chemcad model was also compared with simulations previously carried out in the process simulator Aspen Plus. The agreement between the two sets has proved the accuracy of the model developed in Chemcad. Then, optimum operating conditions were found for a range of ammonia concentration in the basic solution, isentropic expander efficiency and boiler pressure. It is shown that the cycle can be optimized for net work, cooling output, effective first and exergy efficiencies.

scholarly journals Optimization of the antioxidants extraction process from the bacaba (oenocarpus distichus mart.) using response surface methodology

2020 ◽  
Vol 9 (8) ◽  
pp. e229985427
Author(s):  
Paula Beatriz Rocha Sampaio ◽  
Andressa Sousa Pereira ◽  
Caroline Roberta Freitas Pires ◽  
Rodolfo Castilho Clemente ◽  
Guilherme Nobre Lima do Nascimento
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Rural Communities ◽  
Response Surface ◽  
Total Phenolics ◽  
Extraction Process ◽  
Solvent Mixture ◽  
Chemical Characteristics ◽  
Palm Trees ◽  
Efficient Extraction

Bacaba (Oenocarpus distichus Mart) is a fruit that comes from palm trees native from the Arecaceae family and presents important nutritional and socioeconomic value for rural communities. Although being very popular, this fruit has very few cataloged chemical characteristics. The present study aimed to optimize the bacaba antioxidant extraction process by investigating the most efficient extraction interval and the best rotation time, using ethanol and methanol/acetone solvents, with the content of total phenolics and antioxidant activity. Methanol acetone solvent mixture was the most efficient solvent for extracting antioxidants from bacaba, with an extraction time of 90 minutes and 20 minutes of rotation interval at 5,000 rpm.

Experimental Investigation and Optimization of Non-Catalytic In-Situ Biodiesel Production from Rice Bran Using Response Surface Methodology Historical Data Design

2021 ◽  
Vol 10 (4) ◽  
pp. 803-810
Author(s):  
Siti Zullaikah ◽  
Ari Krisna Putra ◽  
Fathi Haqqani Fachrudin ◽  
Rosada Y Naulina ◽  
Sri Utami ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Rice Bran ◽  
Historical Data ◽  
Ethanol Concentration ◽  
Operating Conditions ◽  
Biodiesel Production ◽  
Optimum Operating ◽  
Water Mixture ◽  
Data Design

Rice bran oil (RBO)is claimed to be a potential feedstock for biodiesel production. Non-catalytic in-situ biodiesel production from a low-cost feedstock (rice bran) using subcritical ethanol-water mixture was investigated in this study. The influence of four independent variables, i.e., addition of co-solvent, ethanol concentration, temperature, and time of reactions, on the yield of biodiesel was examined. The results showed that the most effective co-solvent wasethyl acetate and the optimum ethanol concentration, temperature and reaction time were 80% v/v, 200 oC and 3 hours, respectively. The maximum yield of biodiesel was found to be around 80%. The optimization of operating conditions was carried out by response surface methodology (RSM) with historical data design (HDD). The statistical method also suggested similar optimum operating conditions, i.e., 78.44% (v/v) ethanol concentration, 200 oC, and 3.2 hours reaction time with ethyl acetate as a co-solvent. The predicted maximum biodiesel yield was also slightly lower, i.e., 76.98%. Therefore, this study suggests that biodiesel production from rice bran through a non-catalytic in-situ process using a subcritical ethanol-water mixture with ethyl acetate as a co-solvent is very feasible since the yield can reach 80%. The study also found that RSM with HDD can predict the optimum operating conditions with a good accuracy.

scholarly journals Recovery of Phenolic Compounds from Red Grape Pomace Extract through Nanofiltration Membranes

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1649 ◽  
Author(s):  
Jaime A. Arboleda Mejia ◽  
Arianna Ricci ◽  
Ana S. Figueiredo ◽  
Andrea Versari ◽  
Alfredo Cassano ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Phase Inversion ◽  
Total Phenolics ◽  
Operating Conditions ◽  
Grape Pomace ◽  
Hydraulic Permeability ◽  
Permeate Flux ◽  
Phenolics Content ◽  
Valuable Compounds ◽  
Red Grape

The winemaking process generates a large amount of residues such as vine shots, stalks, grape pomace, and wine lees, which were only recently considered for exploitation of their valuable compounds. The purpose of this work was to investigate the performance of nanofiltration for the recovery of phenolic compounds, with bioactive capacity like antioxidant, from red grape pomace extract. Four membranes were compared in this study—three cellulose acetate (CA series: lab-prepared by phase inversion) and one commercial (NF90). All membranes were characterized for their hydraulic permeability and rejection coefficients to reference solutes like saccharose, glucose, raffinose, polyethylene glycol, sodium chloride, and sodium sulfate. Permeation flowrates and rejection coefficients towards total phenolics content, antioxidant activity, proanthocyanidins, glucose and fructose were measured in the nanofiltration of grape pomace extract using selected operating conditions. Among the investigated membranes, the CA400-22 exhibited the highest permeate flux (50.58 L/m2 h at 20 bar and 25 °C), low fouling index (of about 23%), the lowest rejection coefficients towards the reference solutes and the best performance in terms of separation between sugars and phenolic compounds. Indeed, the observed rejections for glucose and fructose were 19% and 12%, respectively. On the other hand, total phenolics content and proanthocyanidins were rejected for 73% and 92%, respectively.

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