scholarly journals Extraction and characterization of bioactive compounds in Vernonia amygdalina leaf ethanolic extract comparing Soxhlet and microwave-assisted extraction techniques

2019 ◽  
Vol 13 (1) ◽  
pp. 414-422 ◽  
Author(s):  
Oluwaseun Ruth Alara ◽  
Nour Hamid Abdurahman ◽  
Chinonso Ishmael Ukaegbu ◽  
Nassereldeen Ahmed Kabbashi
2021 ◽  
Vol 11 (1) ◽  
pp. 430
Author(s):  
Hassan Hadi Mehdi Al Rubaiy ◽  
Ammar Altemimi ◽  
Ali Khudair Jaber Al Rikabi ◽  
Naoufal Lakhssassi ◽  
Anubhav Pratap-Singh

The present study proposes microwave-assisted extraction as a sustainable technique for the biosynthesis of bioactive compounds from rice fermented with Aspergillus flavus (koji). First, fermentation conditions (i.e., pH from 3–12, five temperatures from 20–40 °C, and four culture-fermentation media viz. wheat, wheat bran, malt and rice) were optimized for producing microbial bioactive compounds. Microwave extraction was performed at 2450 MHz and 500 W for 20, 30, and 40 s with seven solvents (distilled water, ethyl acetate, hexane, ethanol, chloroform, diethyl ether, and methanol). The obtained results revealed that ethyl acetate is the most appropriate solvent for extraction. Effects of this ethyl acetate extract were compared with a commercial synthetic antioxidant. Antioxidant properties were enhanced by preventing the oxidation of the linoleic acid (C18H32O2) with an inhibition rate (antioxidant efficacy) of 73.13%. Notably, the ferrous ion binding ability was marginally lower when compared to the disodium salt of ethylenediaminetetraacetic acid (EDTA). Additionally, the obtained total content of phenolic compounds in the ethyl acetate extract of fermented rice (koji) by Aspergillus flavus was 232.11 mg based on gallic acid/mL. Antioxidant compounds in the ethyl acetate extract of fermented rice showed stability under neutral conditions, as well as at high temperatures reaching 185 °C during 2 h, but were unstable under acidic and alkaline conditions. The results demonstrate the efficacy of novel microwave-assisted extraction technique for accelerating antioxidant production during rice fermentation.


2020 ◽  
Vol 16 (1-2) ◽  
Author(s):  
Cassiano Brown da Rocha ◽  
Caciano Pelayo Zapata Noreña

AbstractThe grape pomace is a by-product from the industrial processing of grape juice, which can be used as a source of bioactive compounds. The aim of this study was to separate the phenolic compounds from grape pomace using an acidic aqueous solution with 2 % citric acid as a solvent, using both ultrasound-assisted extraction, with powers of 250, 350 and 450 W and times of 5, 10 and 15 min, and microwave-assisted extraction using powers of 600, 800 and 1,000 W and times of 5, 7 and 10 min. The results showed that for both methods of extraction, the contents of total phenolic compounds and antioxidant activity by ABTS and DPPH increased with time, and microwave at 1,000 W for 10 min corresponded to the best extraction condition. However, the contents of phenolic compounds and antioxidant activity were lower than exhaustive extraction using acidified methanol solution.


2016 ◽  
Vol 70 (6) ◽  
Author(s):  
Van T. Nguyen ◽  
Michael C. Bowyer ◽  
Ian A. van Altena ◽  
Christopher J. Scarlett

Abstractis known as a healing herb which has traditionally been used in the treatment of various diseases such as hepatitis, diabetes and cancer. The extraction parameters have great effects on the extraction efficiency of bioactive compounds and pharmacological activity of the extracts. This study sought to optimise the microwave-assisted extraction parameters for phenolic compounds-enriched extracts and antioxidant capacity from


2019 ◽  
Vol 129 ◽  
pp. 395-404 ◽  
Author(s):  
Nacim Nabet ◽  
Bienvenida Gilbert-López ◽  
Khodir Madani ◽  
Miguel Herrero ◽  
Elena Ibáñez ◽  
...  

Ingeniería ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 77-92
Author(s):  
Ciliana Florez Montes ◽  
Andrés Felipe Rojas González ◽  
Sneyder Rodríguez Barona

Context: Currently, the increase in agroindustrial waste generation has encouraged the search for viable use alternatives. In this paper, four methods to obtain extracts from mango, soursop, and grape peels, as well as and grape seeds, are studied. Their efficiency is analyzed through extraction yields and antioxidant capacity characterization of the extracts. Method: The extraction was performed using solvent, Soxhlet, microwave-assisted, and ultrasound assisted extraction. The characterization of the extracts was made by total phenolic compounds and flavonoids quantification, as well as antioxidant capacity determination, using the DPPH, FRAP, and ORAC tests. Results: It was found that grape seed extracts obtained by different extraction methods, highlighting those obtained by microwave assisted extraction, present a high total content phenolic compounds (>321.381,41 ± 3.476,85 μg Gallic Acid/g) and flavonoids (>103.232,01 ± 4.638,19 μg Quercetin/g), in addition to high antioxidant activity, according to the results of the DPPH (<1,06 ± 0,01), FRAP (>152.280,08 ± 5.197,53 µg TROLOX/g), and ORAC (>124.566,81 ± 581,96 μg TROLOX/g) tests. Conclusions: The results presented in this study suggest that the extracts obtained from grape seeds, especially those obtained by means of microwave-assisted extraction, have a potential use in food and pharmaceutical industries, due to their high antioxidant capacity and their total phenolic compounds and flavonoids content.


2008 ◽  
Vol 91 (5) ◽  
pp. 1124-1129 ◽  
Author(s):  
Takamitsu Otake ◽  
Yoshie Aoyagi ◽  
Masahiko Numata ◽  
Takashi Yarita

Abstract The efficiency of microwave-assisted extraction (MAE) was evaluated for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fish. An isotope dilution method was used for quantification via analysis of the samples by gas chromatography and mass spectrometry. MAE solvent, temperature, and time were optimized, and observed concentrations were compared. The MAE results were also compared to those of other extraction techniques (Soxhlet extraction, pressurized liquid extraction, saponification, and homogenization). Concentrations of PCBs and OCPs obtained by MAE at 120C for 10 min were comparable to those by the other techniques. The results suggest that MAE can be used for the analysis of PCBs and OCPs in fish.


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