Optimal Ultrasound-assisted Extraction Conditions Research Articles

Intensification of bioactive compounds extraction from Feijoa (Feijoa sellowiana Berg.) leaves using ultrasonic waves

In this study, ultrasound-assisted extraction (UAE) of bioactive compounds from Feijoa sellowiana leaves was optimized using response surface methodology. Box-Behnken design was applied to evaluate the effects of ultrasonic intensity, duty cycle and extraction temperature on crude extraction yield (CEY) and radical scavenging activity (RSA) in terms of inhibition of DPPH, OH and ABTS+ radicals. The correlation analysis of mathematical-regression models indicated that quadratic polynomial models could be employed to optimize UAE process. Under the optimal conditions (1569.10W/cm2, 89.00% and 46.00°C) the predicted values of the CEY and RSA of DPPH, OH and ABTS+ were 53.22mgg−1, 78.43%, 62.00% and 81.54%, respectively. High-performance liquid chromatography (HPLC) analysis showed that gallic acid, catechin, ferulic acid, quercetin and apigenin are the major phenolic compounds existed in the extracts. The improvement of UAE was investigated by combining pre-leaching stage (PLS) with optimized UAE conditions (PLS-UAE). Spectrophotometric methods and HPLC analysis results revealed that the bioactive phenolic compounds increased using PLS-UAE, where gallic acid had the highest concentration (123.15±0.34mgg−1). The comparative study results, which has been done between optimized UAE, PLS-UAE and conventional Soxhlet extraction (CSE) revealed that higher CEY (81.11±0.11mgg−1) could be achieved using CSE even through, the quality of extracts in terms of phenolic compounds and RSA was significantly (p-value<0.05) higher using optimized UAE and PLS-UAE. Scanning electron microscopy (SEM) images showed that PLS-UAE can significantly damage the structure of vegetal tissues leads to improved extraction of bioactive compounds.

Ultrasound-assisted extraction of bioactive compounds from Malva sylvestris leaves and its comparison with agitated bed extraction technique.

The effects of ultrasound-assisted extraction (UAE) variables-namely extraction temperature (40-60°C), ultrasonic power (50-150W), and sonication time (40-60min)-on the extractive value (EV) of bioactive phenolics from Malva sylvestris leaves were investigated and optimized using Response surface methodology. The effects of extraction solvents (ethanol, ethyl acetate, and n-hexane) on EV, free radical scavenging activity (FRSA), total phenolic content (TPC), and major bioactive phenolics were studied using agitated bed extraction (ABE), and the results were compared with the UAE findings. Under the optimal UAE conditions (48°C, 110.00W, and 48.77min) the experimental EV was 279.89±0.21mg/g with 71.12±0.15% DPPHsc, 73.35±0.11% ABTSsc, and a TPC of 152.25±0.14mg GAE/g. Ethanolic ABE results in higher EV (320.16±0.25mgg-1) compared to UAE, while the FRSA and TPC values were reduced. HPLC analysis revealed that the concentration of bioactive phenolics increased significantly (p<0.05) under the optimal UAE conditions.

Optimization of ultrasound-assisted extraction of polyphenolic compounds from pomegranate peel using response surface methodology

The pomegranate peel is discarded as waste although it contains high amount of biologically active phenolics and has high value for recycling. In this study we have determined optimal conditions for ultrasound-assisted extraction (UAE) of polyphenols from pomegranate peel using response surface methodology (RSM). The influence of extraction time (X1: 10–60 min), ethanol concentration (X2: 10–90%), solid to solvent ratio (X3: 1:10–1:50) and extraction temperature (X4: 20–80 °C) on total polyphenols content (TPC) as well on content of individual polyphenolic compounds (ellagic acid, gallic acid, punicalagin and punicalin) was investigated. The optimal extraction process conditions were as follows: extraction time of 25 min, ethanol concentration of 59%, solid to solvent ratio of 1:44, and extraction temperature of 80 °C. Experimentally obtained values were in agreement with those predicted by RSM model, indicating suitability of the employed model and the success of RSM in optimizing the extraction conditions.

Optimization of trans lutein from pumpkin (Cucurbita moschata) peel by ultrasound-assisted extraction

In order to avoid the occurrence of high proportion of carotenoid cis isomers during conventional solvent extraction (CSE), ultrasound-assisted extraction (UAE) was used to extract trans lutein and total trans carotenoids from the pumpkin (Cucurbita moschata Duch. cv. Miben) peel. Results showed ethanol–petroleum ether mixture (2:1, v/v) was the suitable solvent for ultrasound-assisted recovery of trans lutein, and high frequency resulted in oxidative degradation of trans lutein from pumpkin peel. The yields of trans lutein and total trans carotenoids positively correlated with ultrasonic power and solvent to material ratio, but negatively correlated with extraction time. Total cis carotenoids gradually increased with the increase of extraction time, but maintained at a low level within a short extraction time. Optimal UAE conditions obtained by Face-centred Central Composite design and response surface methodology were as follows: ultrasonic power of 203W, extraction time of 30min, and solvent to material ratio of 31mL/g. The maximum yields of trans lutein and total trans carotenoids were 237.6μg/g and 344.9μg/g, respectively. However, the total cis carotenoids only accounted for 5.3%. Compared to the CSE, UAE avoided degradation and isomerization, resulting in high yield of trans lutein and trans carotenoids.

Optimization of ultrasound-assisted extraction of bioactive alkaloids from Stephania cambodica using response surface methodology

Abstract An ultrasound-assisted extraction (UAE) was optimized for the extraction of three bioactive alkaloids, namely, palmatine, roemerine, and tetrahydropalmatine from the tuber of Stephania cambodica . The performance of UAE and microwave-assisted extraction (MAE) was compared with that of percolation. UAE and MAE are also more environmentally friendly and use less toxic chemicals. MAE was as efficient as UAE for the extraction of tetrahydropalmatine; however, UAE significantly enhanced extraction yields of palmatine and roemerine. The influence of effective variables viz. liquid–solid ratio, percentage of ethanol, and time on UAE was then investigated using response surface methodology. The optimal UAE conditions were found to be ethanol 52%, time 9 min, and liquid–solid ratio 26.6:1 mL/g. Structural change was conducted by scanning electron microscopy. These findings suggest that UAE is a practical extractive procedure for preparation of alkaloid-rich extract for pharmacological investigation and for analytical control of S. cambodica tuber.

Ultrasound increases the aqueous extraction of phenolic compounds with high antioxidant activity from olive pomace

Olive pomace is a waste produced by the olive oil industry in massive quantities each year. Disposal of olive pomace is difficult due to high concentrations of phenolic compounds, which is an environmental concern. However, phenolic compounds have applications in the health industry. Therefore, extraction of phenolic compounds from olive pomace has the potential to remove an environmentally hazardous portion of pomace while creating an additional source of income for farmers and producers. Using advanced technologies including Ultrasound Assisted Extraction (UAE), combined with water as an extraction solvent, has recently gained popularity. The present study outlines the optimal UAE conditions for the extraction of phenolic compounds with high antioxidant activity from olive pomace. Optimal conditions were developed using RSM for parameters power, time and sample-to-solvent ratio. Total phenolic compounds determined by Folin Ciocalteu method and total major bioactive compounds determined by HPLC as well as antioxidant capacity (DPPH and CUPRAC) were investigated. The optimal conditions for the extraction of phenolic compounds with high antioxidant activity were 2 g of dried pomace/100 mL of water at 250 W power for 75 min. UAE improved the extraction efficiency of water and yielded extracts with high levels of phenolic compounds and strong antioxidant activity.

Plant Phenolics Extraction from Flos Chrysanthemi: Response Surface Methodology Based Optimization and the Correlation Between Extracts and Free Radical Scavenging Activity.

The work of the research investigated the plant phenolics in Flos Chrysanthemi and antioxidant capacities. These results of this study can support the development of antioxidant additive and relative food.

Optimization of Ultrasound-Assisted Extraction of Antioxidants from Apium graveolens L. Seeds using Response Surface Methodology

In this study, optimum conditions for ultrasound-assisted extraction (UAE) of antioxidants from Apium graveolens L. seeds were investigated by Response Surface Methodology (RSM). A Box-Behnken Design (BBD) was used to evaluate the effect of sonication time (5, 10, 15 min), ultrasound power (60, 120, 180 W) and the ratio of extraction solvent in terms of methanol (0, 50, 100%) on antioxidant capacity. The optimal UAE conditions for the parameters investigated were 11 min of sonication time, ultrasound power of 131 W and 100% methanol as an extraction solvent. Under these conditions, UAE of antioxidants from the seeds achieved a maximum of 95.08% in respect to 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity. Additionally, the high value of the adjusted coefficient of determination ( R 2 adj = 0.9192) and the non-significant difference between experimental and predicted values confirmed the validity of the quadratic polynomial model. Hence, UAE is a suitable, fast, economical and practical technique for the extraction of antioxidants from Apium graveolens L. seeds.

Optimization of low power ultrasound-assisted extraction of phenolic compounds from mandarin (Citrus reticulata Blanco cv. Sainampueng) peel

Mandarin peel is a good source of phenolic compounds, which can be extracted by the ultrasound-assisted extraction (UAE) method. This research was to optimize the UAE conditions for maximum mandarin peel extract (MPE) relating to the extract yield, total phenolic content and the content of a mandarin peel rich flavonoid, hesperidin, using a response surface method comparing with the maceration extraction (MAE) method. The results showed that the selected factors (temperature, time and power) have a significant influence on the extraction yield, total phenolic content and hesperidin content. The extraction at 48°C and 56.71W for 40min was considered the optimal UAE condition since it provided the maximum yield (26.52%), total phenolic (15,263.32mgEq gallic/100g DW) and hesperidin (6435.53mg/100g DW). At the same extraction temperature and time, UAE showed greater extraction efficiency than MAE with 1.77 times higher yield than that of MAE.

Optimisation of ultrasound-assisted extraction conditions for phenolic content and antioxidant activities of the alga Hormosira banksii using response surface methodology

This study aimed to optimise ultrasound-assisted extraction (UAE) conditions of the brown alga Hormosira banksii for total phenolic content (TPC) and antioxidant activities including total antioxidant capacity (ABTS), DPPH free radical scavenging capacity (DPPH) and ferric reducing antioxidant power (FRAP) using response surface methodology (RSM). Box–Behnken design was employed to assess the effect of ultrasonic temperature, time and power on the TPC and antioxidant activities of the extracts. The results showed that RSM was an accurate and reliable method in predicting TPC and antioxidant activities (ABTS, DPPH and FRAP) of the extracts with R 2 values of 0.97, 0.96, 0.92 and 0.94, respectively. The ultrasonic temperature and time had the significant impact on TPC and antioxidant capacities. The optimal UAE conditions for the maximal values of TPC and antioxidant activities were of 30 °C, 60 min and power 60%, or 150 W. The values of TPC and antioxidant activities (ABTS, DPPH, FRAP) achieved under these parameters were 23.12 (mg GAE g−1), 85.64 (mg TE g−1), 47.24 (mg TE g−1) and 12.56 (mg TE g−1), respectively. UAE was found to be more efficient in comparison to conventional extraction, with shorter time for extraction and higher of TPC level and antioxidant activities. Therefore, ultrasonic-assisted extraction using RSM is effective for extraction and further isolation and purification of phenolic compounds from H. banksii. In addition, this alga could be a potential rich source of natural antioxidants applied in food and pharmaceutical fields.

Ultrasound-assisted extraction and characterization of anthocyanins from purple corn bran

Purple corn is abundant in anthocyanins, which has attractive colors and potential applications in beneficial health. This study aimed to determine the optimal ultrasound-assisted extraction conditions for purple corn anthocyanins (PCA), and to confirm the anthocyanins from purple corn bran extracts by HPLC-DAD-ESI-MS/MS. Ultrasonic-assisted extraction (UAE) is more time-efficient by comparison of traditional extraction. Meanwhile extraction with corn bran could save the consumption of extractant and improve the extraction yield. The optimal UAE conditions were obtained with the extraction time 35 min, the ultrasonic times 90, solid–liquid ratio 1:8, and the ultrasonic power 400 W. At these conditions, total anthocyanins content was determined as 3.625 ± 0.105 g kg−1, and the extraction yield was 92.45%. The HPLC/MS-MS results showed that the purple corn bran extracts consisted of six kinds of anthocyanins. Practical applications Purple corn is abundant in anthocyanins, which has potential applications in beneficial health, such as antioxidants. The purpose of this study was to find the optimal UAE conditions for purple corn anthocyanins using ultrasound-assisted extraction and identify the anthocyanins from the purple corn bran. The results of this study are suitable for the industrial production of purple corn anthocyanins.

Optimization of the ultrasound-assisted extraction of tryptophan and its derivatives from rice (Oryza sativa) grains through a response surface methodology

An analytical ultrasound-assisted extraction (UAE) technique has been optimized and validated for the extraction of tryptophan and its derivatives from rice grains. A Box–Behnken design in conjunction with a response surface methodology based on six factors and three levels was used to evaluate the effects of the studied factors prior to optimizing the UAE conditions. The significant (p < 0.05) response surface models with high coefficients of determination were fitted to the experimental data. The most significant (p < 0.0001) effect is the solvent-to-sample ratio while quadratic effects caused by temperature and solvent-to-sample ratio were of moderate importance (p < 0.05). The optimal UAE conditions were as follows: extraction time of 5 min, ultrasound amplitude of 30%, cycle of 0.7 s−1, extraction temperature of 30 °C, 8% methanol in water as the extraction solvent at pH 3 and a solvent/solid ratio 5:1. The method validation ensured that appropriate values were obtained for the LOD, LOQ, precision and recovery. Furthermore, the method was successfully applied to the analysis of a number of rice samples of different varieties. It was demonstrated that this particular UAE method is an interesting tool for the determination of tryptophan and tryptophan derivatives in rice grain samples.

Ultrasound-assisted extraction of polysaccharides from Rhododendron aganniphum: Antioxidant activity and rheological properties

In this study, we aimed to optimize the extraction of polysaccharides from the leaves of Rhododendron aganniphum and investigate its rheological properties and antioxidant activity. After optimizing the operating parameters using a Box-Behnken design (BBD), the results showed that the optimal ultrasound-assisted extraction conditions were as follows: extraction temperature, 55°C; liquid-solid ratio, 25:1; extraction time, 2.2h; and ultrasound treatment power, 200W. The optimized experimental yield of polysaccharides by ultrasound-assisted extraction (PUAE) was 9.428%, higher than that obtained by hot water extraction (PHWE) for 12h at the same liquid-solid ratio and extraction temperature. In the in vitro antioxidant activity tests, PUAE had higher positive radical scavenging activity for hydroxyl, superoxide and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals than PHWE. However, PUAE and PHWE solutions had similar intermolecular interactions in the steady-shear flow and dynamic viscoelasticity tests, resulting in similar macroscopic behaviour. With respect to the apparent viscosity, storage modulus (G′) and loss modulus (G″) of PUAE were lower at the same shear rate or angular frequency. All PUAE solutions exhibited non-Newtonian shear-thinning pseudoplastic behaviour that was accurately described by the Carreau model but was better fit by the power-law model at high shear rates (≥1/s), which demonstrated that the variation in the apparent viscosity dependence was greater at higher concentrations and shear rates. The G′ and G″ of the solutions increased as the experimental frequency increased from 0.05 to 500rad/s under all experimental concentrations, and the modulus crossover point decreased gradually with increasing PUAE concentration. The above results demonstrated that the ultrasound-assisted extraction methods gave a higher yield of polysaccharides from the leaves of R. aganniphum with a shorter extraction time than the hot water extraction method, which could affect the apparent viscosity and dynamic viscoelasticity. PUAE presented good radical scavenging activity for DPPH, superoxide and hydroxyl radicals in vitro and could be used as a natural antioxidant in the food and medical industries.

Ultrasound-assisted extraction of natural antioxidants from the flower of Limonium sinuatum: Optimization and comparison with conventional methods

Natural antioxidants are widely used as dietary supplements or food additives. An optimized method of ultrasound-assisted extraction (UAE) was proposed for the effective extraction of antioxidants from the flowers of Limonium sinuatum and evaluated by response surface methodology. In this study, ethanol concentration, ratio of solvent to solid, ultrasonication time and temperature were investigated and optimized using a central composite rotatable design. The optimum extraction conditions were as follows: ethanol concentration, 60%; ratio of solvent to solid, 56.9:1mL/g; ultrasonication time, 9.8min; and temperature, 40°C. Under the optimal UAE conditions, the experimental values (483.01±15.39μmolTrolox/gDW) matched with those predicted (494.13μmolTrolox/gDW) within a 95% confidence level. In addition, the antioxidant activities of UAE were compared with those of conventional maceration and Soxhlet extraction methods, and the ultrasound-assisted extraction could give higher yield of antioxidants and markedly reduce the extraction time.

Effect of oil extraction assisted by ultrasound on the physicochemical properties and fatty acid profile of pumpkin seed oil (Cucurbita pepo)

The effects of amplitude and time of ultrasound-assisted extraction on the physicochemical properties and the fatty acid profile of pumpkin seed oil (Cucurbita pepo) were evaluated. Ultrasound time (5–30min) and the response variables amplitude (25–100%), extraction yield, efficiency, oxidative stability in terms of the free fatty acids (FFA) of the plant design comprising two independent experiments variables, peroxide (PV), p-anisidine (AV), totox value (TV) and the fatty acid profile were evaluated. The results were analyzed by multiple linear regression. The time and amplitude showed significant differences (P<0.05) for all variables. The highest yield of extraction was achieved at 5min and amplitude of 62.5% (62%). However, the optimal ultrasound-assisted extraction conditions were as follows: ultrasound time of 26.34min and amplitude of 89.02%. All extracts showed low FFA (2.75–4.93% oleic acid), PV (1.67–4.68meq/kg), AV (1.94–3.69) and TV (6.25–12.55) values. The main fatty acids in all the extracts were oleic and linoleic acid. Therefore, ultrasound-assisted oil extraction had increased performance and reduced extraction time without affecting the oil quality.

Ultrasound-assisted extraction of flavonoids and phenolic compounds from Ocimum tenuiflorum leaves

Ultrasound-assisted extraction (UAE) was optimized for extraction of flavonoids and phenolics from dried leaves of Ocimum tenuiflorum using response surface methodology with a central composite rotatable design and independent variables of ethanol concentration (30-70%), sonication time (5-15 min), and ultrasonic energy density (UED) (0.15-0.35 W/cm3). A significant (p 0.05). Linear and quadratic effects of independent variables significantly (p<0.001) influenced flavonoid content (FC) and total phenolic content (TPC) yields. Optimized UAE conditions of ethanol concentration, sonication time, and UED were 55.34%, 11.71 min, and 0.26 W/cm3, respectively, resulting in predicted FC and TPC yields of 6.69 mg of quercetin equivalents QE/g and 9.41 mg of gallic acid equivalents GAE/g, respectively. HPLC analysis revealed different phenolic and flavonoid compounds. UAE extracts exhibited better in vitro antioxidant activities and thermo-oxidative stability values than conventional solvent extracts.

Optimization of ultrasound-assisted extraction to obtain mycosterols from Agaricus bisporus L. by response surface methodology and comparison with conventional Soxhlet extraction

Ergosterol, a molecule with high commercial value, is the most abundant mycosterol in Agaricus bisporus L. To replace common conventional extraction techniques (e.g. Soxhlet), the present study reports the optimal ultrasound-assisted extraction conditions for ergosterol. After preliminary tests, the results showed that solvents, time and ultrasound power altered the extraction efficiency. Using response surface methodology, models were developed to investigate the favourable experimental conditions that maximize the extraction efficiency. All statistical criteria demonstrated the validity of the proposed models. Overall, ultrasound-assisted extraction with ethanol at 375W during 15min proved to be as efficient as the Soxhlet extraction, yielding 671.5±0.5mg ergosterol/100gdw. However, with n-hexane extracts with higher purity (mg ergosterol/g extract) were obtained. Finally, it was proposed for the removal of the saponification step, which simplifies the extraction process and makes it more feasible for its industrial transference.

Ultrasound-assisted extraction of azadirachtin from dried entire fruits of Azadirachta indica A. Juss. (Meliaceae) and its determination by a validated HPLC-PDA method

Azadirachta indica A. Juss., also known as neem, is a Meliaceae family tree from India. It is globally known for the insecticidal properties of its limonoid tetranortriterpenoid derivatives, such as azadirachtin. This work aimed to optimize the azadirachtin ultrasound-assisted extraction (UAE) and validate the HPLC-PDA analytical method for the measurement of this marker in neem dried fruit extracts. Box–Behnken design and response surface methodology (RSM) were used to investigate the effect of process variables on the UAE. Three independent variables, including ethanol concentration (%, w/w), temperature (°C), and material-to-solvent ratio (gmL−1), were studied. The azadirachtin content (µgmL−1), i.e., dependent variable, was quantified by the HPLC-PDA analytical method. Isocratic reversed-phase chromatography was performed using acetonitrile/water (40:60), a flow of 1.0mLmin−1, detection at 214nm, and C18 column (250×4.6mm2, 5µm). The primary validation parameters were determined according to ICH guidelines and Brazilian legislation. The results demonstrated that the optimal UAE condition was obtained with ethanol concentration range of 75–80% (w/w), temperature of 30°C, and material-to-solvent ratio of 0.55gmL−1. The HPLC-PDA analytical method proved to be simple, selective, linear, precise, accurate and robust. The experimental values of azadirachtin content under optimal UAE conditions were in good agreement with the RSM predicted values and were superior to the azadirachtin content of percolated extract. Such findings suggest that UAE is a more efficient extractive process in addition to being simple, fast, and inexpensive.

Optimization of ultrasound-assisted extraction of polyphenols from maize filaments by response surface methodology and its identification.

Maize filaments (MF) are the outer thread-like part of corn, which are widely used in traditional and official medicine. In the current study, central composite design (CCD) was used to investigate the effect of process variables on polyphenols contents from MF by ultrasound-assisted extraction (UAE). Results showed that the obtained optimal UAE conditions were as follows: extraction power of 520.01 W, ethanol concentration of 61.08%, and a solvent-to-material ratio of 26.83 mL/g for polyphenols extraction. These experimental values under optimal conditions were consistent with the predicted values with polyphenols content of 7.1±0.015 mg/g. Sixteen phenolic compounds, including gallic acid, catechin, picatechin, hyperoside etc were identified in MF polyphenols extractions by HPLC-MS/MS method. The antioxidant activity of the MF polyphenols extractions were also studied, which showed that MF polyphenols extractions have excellent radical scavenging ability for ABTS radicals, •OH, DPPH radicals and •O 2 -, and 42.56 ± 1.24% of lipid oxidation inhibition.

Ultrasound-assisted extraction of resveratrol from functional foods: Cookies and jams

Rapid extraction techniques with ultrasonic systems have been established to extract resveratrol from two functional foods, namely cookies and jams. The ultrasound-assisted extraction (UAE) was optimized using a full factorial design with three variables: solvent composition (10–70% and 30–90% methanol in water for cookies and jams, respectively), solvent-to-solid ratio (10:1–40:1), and ultrasonic probe diameter (2 and 7mm). The extraction kinetics (5–30min) were studied to confirm the full recovery of resveratrol from the functional foods. The resveratrol was quantified by Ultrahigh Performance Liquid Chromatography with a Fluorescense Detector (UPLC-FD).The solvent composition was found to have a significant effect on the recovery (p<0.005) for both of the functional foods studied. The optimal UAE conditions were 90% methanol in water, an extraction time of 10min, an ultrasonic probe with a diameter of 7mm, and solvent-to-solid ratios of 40:1 and 10:1, respectively, for cookies and jams.The methods developed in this study show a high precision in terms of Coefficient of Variance (CV), with values of less than 5% for both repeatability and intermediate precision. The applicability of the methods to real samples has been evaluated and it was confirmed that the methods are suitable for the extraction of resveratrol from cookies and jams.