scholarly journals Direct ultrasound-assisted extraction and characterization of phenolic compounds from fresh houseleek (Sempervivum marmoreum L.) leaves

2018 ◽  
Vol 72 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Ivana Karabegovic ◽  
Sasa Stojicevic ◽  
Dragan Velickovic ◽  
Nada Nikolic ◽  
Miodrag Lazic

The effects of ultrasound power and frequency on the yield of total extractive substances (TES), total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (AOA) of fresh houseleek leaves extracts obtained by direct ultrasound-assisted extraction (DUAE) were studied. Preliminary extraction of plant material was performed using methanol, acetone and 2-propanol by Soxhlet extraction. It was found that maximum TES yield could be obtained by methanol extraction (2.91?0.02), followed by acetone and 2-propanol with a TES yield of 2.32?0.01 and 2.01?0.03 g per 100 g of fresh plant material, respectively. In the fresh houseleek leaves extracts obtained by DUAE and methanol as the chosen solvent, TPC, TFC and AOA were in the ranges of: 40.5?85.9 mg gallic acid/g dry extract, 12.7?19.3 mg rutin/g dry extract and 24.6?108.2?g/ml, respectively. The results showed that the increase in the ultrasound power and extraction time have positive and significant (p < 0.05) effects on the TPC, TFC and AOA, while the increase in the ultrasound frequency leads to a decrease in the TPC, TFC and AOA of the extracts. A chromatographic analysis of crude extract identified the following: kaempferol 3-O-(6??-O-malonylglucoside)- 7-O-glucosyde, kaempferol 3-O-glucoside-7-O-rhamnoside, luteolin 5-O-(6??-O-malonylglucoside), kaempferol 3-O-(6??-O-acetylglucoside)-7-O-rhamnoside, genkwanin 5-O-glucoside, luteolin 5-O-(6??-O-malonylglucoside), kaempferol 3-O-(6??-O-malonylglucoside), kaempferol 3-O-rhamnoside, quercetin, genkwanin 4?-O-glucoside and hyperoside.

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 931
Author(s):  
Cristina Reche ◽  
Carmen Rosselló ◽  
Mónica M. Umaña ◽  
Valeria Eim ◽  
Susana Simal

Valorization of an artichoke by-product, rich in bioactive compounds, by ultrasound-assisted extraction, is proposed. The extraction yield curves of total phenolic content (TPC) and chlorogenic acid content (CAC) in 20% ethanol (v/v) with agitation (100 rpm) and ultrasound (200 and 335 W/L) were determined at 25, 40, and 60 °C. A mathematical model considering simultaneous diffusion and convection is proposed to simulate the extraction curves and to quantify both temperature and ultrasound power density effects in terms of the model parameters variation. The effective diffusion coefficient exhibited temperature dependence (72% increase for TPC from 25 °C to 60 °C), whereas the external mass transfer coefficient and the equilibrium extraction yield depended on both temperature (72% and 90% increases for TPC from 25 to 60 °C) and ultrasound power density (26 and 51% increases for TPC from 0 (agitation) to 335 W/L). The model allowed the accurate curves simulation, the average mean relative error being 5.3 ± 2.6%. Thus, the need of considering two resistances in series to satisfactorily simulate the extraction yield curves could be related to the diffusion of the bioactive compound from inside the vegetable cells toward the intercellular volume and from there, to the liquid phase.


Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 248 ◽  
Author(s):  
Ivana Savic Gajic ◽  
Ivan Savic ◽  
Ivana Boskov ◽  
Stanko Žerajić ◽  
Ivana Markovic ◽  
...  

The aim of this study was to optimize the ultrasound-assisted extraction of phenolic compounds from black locust (Robiniae pseudoacaciae) flowers using central composite design. The ethanol concentration (33–67%), extraction temperature (33–67 °C), and extraction time (17–33 min) were analyzed as the factors that impact the total phenolic content. The liquid-to-solid ratio of 10 cm3 g−1 was the same during extractions. The optimal conditions were found to be 59 °C, 60% (v/v) ethanol, and extraction time of 30 min. The total phenolic content (TPC = 3.12 gGAE 100 g−1 dry plant material) and antioxidant activity (IC50 = 120.5 µg cm−3) of the extract obtained by ultrasound-assisted extraction were compared with those obtained by maceration (TPC = 2.54 gGAE 100 g−1 dry plant material, IC50 = 150.6 µg cm−3) and Soxhlet extraction (TPC = 3.22 gGAE 100 g−1 dry plant material, IC50 = 204.2 µg cm−3). The ultrasound-assisted extraction gave higher total phenolic content and better antioxidant activity for shorter extraction time so that it represents the technique of choice for the extraction of phenolic compounds. The obtained extract, as the source of antioxidants, can be applied in the pharmaceutical and food industries.


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.


2021 ◽  
Vol 43 ◽  
pp. e55564
Author(s):  
Suelen Siqueira dos Santos ◽  
Carolina Moser Paraíso ◽  
Letícia Misturini Rodrigues ◽  
Grasiele Scaramal Madrona

Blueberry and raspberry pomace are a rich source of bioactive compounds that have not been commercially utilized yet, and ultrasound-assisted technology can efficiently extract these compounds. Also, the use of water as a solvent added to the ultrasound-assisted technology improves this eco-friendly process. Therefore, an aqueous eco-friendly extraction, including extraction time and ultrasound presence or absence (conventional extraction) was performed in order to extract bioactive compounds from blueberry and raspberry pomace. Response parameters included levels of anthocyanins, phenolic compounds, and flavonoids, and antioxidant activity determined by DPPH, ABTS, and FRAP methods. Analysis of variance results indicated that ultrasound-assisted extraction for 45 min. was feasible to extract the bioactive compounds. The antioxidant content of the extract obtained by the ultrasound-assisted process was 1.4 times higher on average and the total phenolic concentration was 1.6 times higher (for blueberry 5.02 and for raspberry 2.53 mg gallic acid equivalent/g) compared with those obtained by the conventional process. Thus, the ultrasound-assisted extraction method can be a profitable alternative to extract bioactive compounds from blueberry and raspberry pomace, as it is energy efficient, requires fewer chemicals, and produces less effluent. This eco-friendly technology is therefore viable for food, nutraceutical, and cosmetic industries, and also for reducing food waste.


Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 326 ◽  
Author(s):  
María José Aliaño-González ◽  
Estrella Espada-Bellido ◽  
Marta Ferreiro-González ◽  
Ceferino Carrera ◽  
Miguel Palma ◽  
...  

Two optimized methods for ultrasound-assisted extraction were evaluated for the extraction of two types of acai bioactive compounds: Total anthocyanins (TAs) and total phenolic compounds (TPCs). For the extraction optimization, a Box Behnken factorial design of different variables in the following intervals was used: Methanol-water (25%–75%) for solvent composition, temperatures between 10 and 70 °C, amplitude in the range between 30% and 70% of the maximum amplitude −200 W), extraction solvent pH (2–7), the ratio for sample-solvent (0.5 g:10 mL–0.5 g:20 mL), and cycle between 0.2 and 0.7 s. The extraction kinetics were studied using different periods between 5 and 30 min. TA and TPC were analyzed by UHPLC and the Folin–Ciocalteu method, respectively. Optimized conditions for TA were: 51% MeOH in water, 31 °C temperature, pH 6.38, cycle 0.7 s, 65% amplitude, and 0.5 g:10 mL of sample-solvent ratio. Optimized conditions for the TPC were: 49% MeOH in water, 41 °C temperature, pH 6.98, cycle 0.2 s, 30% amplitude, and 0.5 g:10 mL of sample-solvent ratio. Both methods presented a relative standard deviation below 5% in the precision study. The suitability of the methods was tested in real samples. It was confirmed that these methods are feasible for the extraction of the studied bioactive compounds from different açai matrices.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Claudia Giovagnoli-Vicuña ◽  
Sebastián Pizarro ◽  
Vilbett Briones-Labarca ◽  
Álvaro Delgadillo

Square wave voltammetry (SWV) analysis was used to assess the antioxidant interactions (synergism, addition, and antagonism) of fruit mixture extracts from grape (G), lemon (L), and blueberry (B) obtained by conventional extraction, ultrasound-assisted extraction, and high hydrostatic pressure extraction. The experimental results showed antagonistic antioxidant effects in all binary mixture extracts (L-G, L-B, and G-B). In DPPH and FRAP assays, the greatest antioxidant capacity was found in the G-B mixture (108.7 and 108.8 μmol TE g−1 dry extract, respectively) obtained by high hydrostatic pressure extraction; however, there were no significant differences when measured by ultrasound-assisted extraction. For TPC and TFC assays, the greatest values were for G-B (6.67 mg GA g−1 dry extract) and L-G (1.63 mg QE g−1 dry extract), respectively. SWV experiments showed antagonistic behavior in the mixtures. Among the different ratios of the fruit mixture extracts evaluated by SWV, 1 : 1 (w/w) combination showed the greatest antagonistic antioxidant effects. SWV suggests the components of the mixture with the highest antioxidant capacity oxidize after mixing. The results indicate that the presence of natural bioactive antioxidants in fruit mixtures does not guarantee that the interactions are synergistic.


2015 ◽  
Vol 29 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Jana Šic Žlabur ◽  
Sandra Voća ◽  
Nadica Dobričević ◽  
Mladen Brnčić ◽  
Filip Dujmić ◽  
...  

Abstract The aim of the present study was to reveal an effective extraction procedure for maximization of the yield of steviol glycosides and total phenolic compounds as well as antioxidant activity in stevia extracts. Ultrasound assisted extraction was compared with conventional solvent extraction. The examined solvents were water (100°C/24 h) and 70% ethanol (at 70°C for 30 min). Qualitative and quantitative analyses of steviol glycosides in the extracts obtained were performed using high performance liquid chromatography. Total phenolic compounds, flavonoids, and radical scavenging capacity by 2, 2-azino-di-3-ethylbenzothialozine- sulphonic acid) assay were also determined. The highest content of steviol glycosides, total phenolic compounds, and flavonoids in stevia extracts were obtained when ultrasound assisted extraction was used. The antioxidant activity of the extracts was correlated with the total amount of phenolic compounds. The results indicated that the examined sonication parameters represented as the probe diameter (7 and 22 mm) and treatment time (2, 4, 6, 8, and 10 min) significantly contributed to the yield of steviol glycosides, total phenolic compounds, and flavonoids. The optimum conditions for the maximum yield of steviol glycosides, total phenolic compounds, and flavonoids were as follows: extraction time 10 min, probe diameter 22 mm, and temperature 81.2°C.


2011 ◽  
Vol 65 (4) ◽  
pp. 473-477 ◽  
Author(s):  
Jelena Mladenovic ◽  
Pavle Maskovic ◽  
Rados Pavlovic ◽  
Blaga Radovanovic ◽  
Gordana Acamovic-Djokovic ◽  
...  

This study was aimed at evaluating the antioxidant activity and efficacy of the ethanolic extract of the ultrasonic extracts of leek Allium porrum L. Ethanolic (50%; v/v) extracts of edible leek parts (stem and leaf) were prepared by ultrasound-assisted extraction, which was followed by evaluation of total phenols, flavonoids and antioxidant activity. Total phenols were determined using the modified Folin-Ciocalteu method. Antioxidant activity was assessed by scavenging the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The results of antioxidant activity were compared with control antioxidants: vitamin C and BHT. The higher content of phenols (69.46 mg GAE/g dry extract) and flavonoids (33.53 mg CE/g dry extract) was found in the ethanolic extract of leek stem. The measured values of IC50 were 98.90 g/ml and 61.05 g/ml for the ethanolic extract of leek leaf and stem, respectively.


Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1665
Author(s):  
Shusheng Wang ◽  
Amy Hui-Mei Lin ◽  
Qingyou Han ◽  
Qin Xu

Potato peels (PPs) are generally considered as agriculture waste. The United States alone generates over one million tons of PPs a year. However, PPs contain valuable phenolic compounds with antioxidant activities. In this study, we evaluated the efficiency of ultrasound-assisted extraction techniques in recovering antioxidants from PPs. These techniques included a direct ultrasound-assisted extraction (DUAE), an indirect ultrasound-assisted extraction (IUAE), and a conventional shaking extraction (CSE). Results of this study showed that DUAE was more effective in extracting phenolic compounds than IUAE and CSE. We also evaluated the factors affecting the yield of total phenolic compounds (TPC) in DUAE, including the temperature, time, acoustic power, ratio of solvent to solids, and size of PPs particles. TPC yield of DUAE was higher, and the extraction rate was faster than IUAE and CSE. Furthermore, TPC yield was strongly correlated to the temperature of the mixture of PPs suspension. SEM images revealed that the irradiation of ultrasound energy from DUAE caused micro-fractures and the opening of PPs cells. The extract obtained from DUAE was found to have antioxidant activity comparable to commercial synthetic antioxidants. Results of this preliminary study suggest that DUAE has the potential to transform PPs from agricultural waste to a valuable ingredient. A future systematic research study is proposed to advance the knowledge of the impact of processing parameters in the kinetics of phenolic compounds extraction from potato peels using various extraction methods.


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