scholarly journals Phenolic Profile, Antioxidant Capacity and Antimicrobial Activity of Nettle Leaves Extracts Obtained by Advanced Extraction Techniques

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6153
Author(s):  
Ivona Elez Elez Garofulić ◽  
Valentina Malin ◽  
Maja Repajić ◽  
Zoran Zorić ◽  
Sandra Pedisić ◽  
...  

Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS2 and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative Pseudomonas fragi ATCC 4973 and Campylobacter jejuni NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.

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


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.


Heliyon ◽  
2020 ◽  
Vol 6 (5) ◽  
pp. e03845 ◽  
Author(s):  
G. Astrid Garzón ◽  
Carlos Y. Soto ◽  
Marcela López-R ◽  
Kenneth M. Riedl ◽  
Cindi R. Browmiller ◽  
...  

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 678
Author(s):  
Ao Shang ◽  
Min Luo ◽  
Ren-You Gan ◽  
Xiao-Yu Xu ◽  
Yu Xia ◽  
...  

In this study, the effects of microwave-assisted extraction conditions on antioxidant capacity of sweet tea (Lithocarpus polystachyus Rehd.) were studied and the antioxidants in the extract were identified. The influences of ethanol concentration, solvent-to-sample ratio, microwave power, extraction temperature and extraction time on Trolox equivalent antioxidant capacity (TEAC) value, ferric reducing antioxidant power (FRAP) value and total phenolic content (TPC) were investigated by single-factor experiments. The response surface methodology (RSM) was used to study the interaction of three parameters which had significant influences on antioxidant capacity including ethanol concentration, solvent-to-sample ratio and extraction time. The optimal conditions for the extraction of antioxidants from sweet tea were found as follows—ethanol concentration of 58.43% (v/v), solvent-to-sample ratio of 35.39:1 mL/g, extraction time of 25.26 min, extraction temperature of 50 ℃ and microwave power of 600 W. The FRAP, TEAC and TPC values of the extract under the optimal conditions were 381.29 ± 4.42 μM Fe(II)/g dry weight (DW), 613.11 ± 9.32 μM Trolox/g DW and 135.94 ± 0.52 mg gallic acid equivalent (GAE)/g DW, respectively. In addition, the major antioxidant components in the extract were detected by high-performance liquid chromatography with diode array detection (HPLC-DAD), including phlorizin, phloretin and trilobatin. The crude extract could be used as food additives or developed into functional food for the prevention and management of oxidative stress-related diseases.


2012 ◽  
Vol 16 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Višnja Katalinic ◽  
Sonja Smole Mozina ◽  
Ivana Generalic ◽  
Danijela Skroza ◽  
Ivica Ljubenkov ◽  
...  

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