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Ultrasound-assisted extraction of oil from tea seed

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Abstract

Ultrasound-assisted extraction (UAE) of oil from tea seeds, and the effects of some operating parameters such as ultrasonic power, extraction time, extraction temperature and solvent to solid ratio on the yield of tea seed oil were investigated; some of the results were compared with those of the conventional method. It was found that UAE requires a shorter extraction time and a reduced solvent consumption. The yield of tea seed oil increased with the increase of the ultrasonic power and decreased as the temperature increased. The fatty acid compositions of the oils extracted by the ultrasound-assisted method and the conventional method were analyzed using gas chromatography. The result showed no significant affect on the compositions of the tea seed oil by the application of ultrasound. The ultrasound-assisted extraction (UAE) can enhance the extraction efficiency, facilitating solvent penetration into the plant material and allowing the intracellular product release. Ultrasound also agitates the solvent used for extraction, thus increasing the contact surface area between the solvent and the targeted compounds by permitting greater penetration of the solvent into the sample matrix. Therefore, UAE reduces extraction time as well as solvent consumption. In addition, UAE can be carried out at a lower temperature, thus avoiding thermal damage to the extracts and minimizing the loss of bioactive compounds. Therefore, it may serve as an effective method for extraction of oil from tea seeds.

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... Tohumlardan yağ eldesi günümüzde genellikle soğuk/sıcak pres veya çözücü ekstraksiyon yöntemi ile gerçekleştirilmektedir (Shalmashi 2009;Martinez vd., 2012;Dabrowski vd., 2017). Presleme genellikle yüksek enerji tüketimine karşın düşük verim sağlamakta olup çözücü ekstraksiyonunda ise çevreye zararlı kimyasalların kullanımı ve ekstraksiyon süresinin uzun olması gibi bir takım sıkıntılar bulunmaktadır (Shalmashi 2009). ...
... Tohumlardan yağ eldesi günümüzde genellikle soğuk/sıcak pres veya çözücü ekstraksiyon yöntemi ile gerçekleştirilmektedir (Shalmashi 2009;Martinez vd., 2012;Dabrowski vd., 2017). Presleme genellikle yüksek enerji tüketimine karşın düşük verim sağlamakta olup çözücü ekstraksiyonunda ise çevreye zararlı kimyasalların kullanımı ve ekstraksiyon süresinin uzun olması gibi bir takım sıkıntılar bulunmaktadır (Shalmashi 2009). Bu iki yöntemin dışında ise daha maliyetli teknikler olan enzimatik ve süperkritik karbondioksit altında ekstraksiyon yöntemlerine de başvurulabilmektedir (Martinez vd., 2012;Li vd., 2015;de Mello vd., 2017). ...
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... Extraction enhancement by ultrasound has been attributed to the propagation of ultrasound pressure waves, and resulting cavitation phenomena [10]. Ultrasounds cause mechanical effects: due to the agitation of the solvent, the contact surface area between solid and solvent is increased and thus, greater infiltration of the solvent into the matrix is facilitated [11][12][13]. Recently, it was shown that the yield of oil by UAE was similar to that one reached by Soxhlet extraction [14]. ...
... The results clearly show that the duration of UAE has a positive influence on the yield. These findings are in accordance with previously mentioned literature reports: in the cases of oil extracted from thyme leaves [11], tea [12] or flax seeds [13], it has been shown that UAE can increase extraction efficiency due to acoustic cavitations that enables disruption of cell walls to take place (as evidenced by scanning electron microscopy, [30]), thus facilitating diffusion of the solvent into the sample matrix and the release of intracellular substances. Evidently, the yield increases up to 90 min of ultrasound-assisted extraction; while for longer extraction periods it remains constant. ...
... However, it is important to underline the environmentalfriendly aspect of extraction methodology used in this work. Since it is well known that use of organic solvents is not environmentally friendly, we decided to proceed with UAE using a low solvent to solid ratio (equal to 2), although it is well known that with higher values of this ratio, higher yields can be reached: for example, in the case of tea seed oil UAE, a solvent to solid ratio equal to 6 has been shown to be the most appropriate [12], while a solvent to solid ratio equal to 10 was used for oil extraction from grape seeds [14]. It should be noted that all experimental conditions applied here for UAE: temperature, solvent to solid ratio and duration of treatment are more environmentally favorable than those applied in the conventional Soxhlet methodology. ...
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The goal of this work was to investigate the relationship between antioxidants' content and the oxidative stabilities of grape seed oils obtained from the Cabernet Sauvignon variety. The samples of grape seed oils were obtained by ultrasound assisted extraction. The time of extraction was varied, while the other relevant parameters: extraction temperature, solvent to solid ratio and sonication power were kept constant. For the sake of comparison, the extraction was also done using the conventional Soxhlet method. For all the oil samples obtained, the contents of total phenolic compounds (TPC), alpha-tocopherol and fatty acids were determined using relevant analytic methods. Importantly, in the present study, the modern analytical techniques for estimation of antioxidant capacity (measuring the chemiluminescence intensity of a luminol-hemin solution) and oxidative stability [differential scanning calorimetry (DSC), coupled with thermogravimetry (TG)] were proposed. The obtained results prove that ultrasonic irradiation enables effective extraction of grape seed oil. It was shown that the extractive yields and the amounts of total phenolic compounds and alpha-tocopherol increase with time of extraction; the optimum time was determined. Results obtained in this work show that, for both oxidative stability and antioxidant capacity, TPC have a more important role then alpha-tocopherol.
... The ultrasound-assisted extraction process of uvaia leaves was performed using a 2 3 full factorial experimental design with triplicate of the center point to analyze the effect of the variables "amplitude," "temperature," and "solid to liquid ratio" on the extraction yield, as well as α-amyrin and β-amyrin content. The variables were selected based on previous literature data [34][35][36] and on preliminary tests. The experiments were performed at amplitude of 30, 50, and 70% of the nominal power, temperatures of 40, 50, and 60°C, and solid to liquid ratio of 1:10, 1:15, and 1:20 (W/V). ...
... For the ultrasound-assisted extraction, fixing the amplitude, an increase occurs in yield with increasing temperature, regardless of the mass/solvent ratio used. This can be explained by the fact that the temperature affects many physical properties, such as diffusivity, viscosity, solubility, surface tension, and vapor pressure [34]. At a higher temperature, the mass transfer increases because of the decreased viscosity and density of the liquid [45]. ...
... When fixing the values of amplitude and temperature, the increase in the ratio causes an increase in yield. In general, the components can be more effectively dissolved using higher volumes, leading to increased extraction yield [34]. Other authors confirmed that when the ratio was increased, the extraction efficiency was positively increased [19,34]. ...
Article
Uvaia (Eugenia pyriformis Cambess.) leaves were subjected to extraction with supercritical fluid extraction (SFE) and ultrasound-assisted extraction (UAE) under different conditions and the results were compared with a conventional maceration extraction. The extracts obtained with SFE were chemically characterized by gas chromatography–mass spectrometry (GC–MS), which showed that β-amyrin (53.72%) and α-amyrin (24.63%) were their main compounds. The best results for SFE and UAE yieldings were 1.69% and 1.79%, respectively. The best results for amyrin content, by extract weight, were 81.19% for SFE and 77.03% for UAE. The highest amyrin content was 11.40 g of the isomers mixture per kg of dry leaf in SFE and 11.46 g kg⁻¹ in UAE. Scanning electron microscopy analysis showed differences in leaf particles before and after the extraction process, caused by the removal of compounds by the extraction techniques studied.
... In the meantime, development in high-intensity ultrasound technology has increased its use in several industries (Abdullah and Koc, 2013). Ultrasound-assisted extraction (UAE) is a solvent extraction technique that has been widely studied and it can enhance the extraction effi ciency by reducing the extraction time, as well as the energy and solvent consumption (Fang et al., 2014;Goula, 2013;Shalmashi, 2009). Extraction enhancement by ultrasound can be attributed to the propagation of ultrasound pressure waves and resulting cavitation forces, where bubbles can explosively collapse and generate localized pressure causing ruptures in the plant tissue and improving the release of intracellular substances into the solvent (Goula, 2013;Knorr et al., 2002). ...
... They concluded that the use of a high intensity ultrasound in oil extraction processes reduced the oil extraction time by enhancing the oil extraction rates during the diff usion stage. Some studies also found that UAE requires a signifi cant shorter time and reduced solvent consumption (Shalmashi, 2009;Zhang et al., 2008). In the study of Zen-Shan Zhang et al (Zhang et al., 2008), the extraction yields of fl axseed oil increased with the increase of ultrasonic power and decreased as the temperature was increased. ...
Article
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This study reports experimental kinetic data and modeling for the extraction of oil from kiwifruit seeds by ultrasound-assisted extraction (UAE) with ethanol. The fatty acid profile, tocopherol and total lipids content in the oil obtained were determined. The variables temperature and ultrasonic power were investigated based on the oil extraction yields using a central composite experimental design. The overall yields obtained were compared to conventional Soxhlet extraction with n-hexane and with ethanol. The extractions presented high extraction rates with overall yield ranged between 19 and 33%, and the extraction yields increased with the temperature. The fatty acid profile showed a high content of omega-3 fatty acids (63.20%) and the Vitamin E content was 14.97 ± 0.38 mg/100 g oil, with ɤ-tocopherol constituting 49% of the total tocopherol. A second-order kinetic model was applied to describe the ultrasound extraction process under different conditions. The numerical results were compared with the experimental extraction yields and presented a good correlation. The extraction technique investigated was found to be suitable for extraction of oil from kiwifruit seeds, in which the great potential of kiwifruit oil obtained from UAE was demonstrated.
... Higher power level gave higher TPC for nettle extracts (Fig. 1c). Increasing power level of ultrasound supplies a faster and stronger mixing effect that reduces external resistance and enhances the mass transfer, so increasing power enhances the extraction and increases the efficiency (Chemat et al. 2004;Ma et al. 2009;Shalmashi 2009). By means of ultrasound, mixing occurs in the solid-liquid interface. ...
... Longer extraction times increased the extracted amount of phenolics. This is in accordance with other leaching studies (Chemat et al. 2004;Rostagno et al. 2003;Shalmashi 2009). TPC of extracts at 1:30 solid to solvent ratio was significantly higher than 1:20 and 1:10 solid to solvent ratios. ...
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In this study, extraction of phenolic compounds from nettle by microwave and ultrasound was studied. In both microwave and ultrasound-assisted extractions, effects of extraction time (5–20 min for microwave; 5–30 min for ultrasound) and solid to solvent ratio (1:10, 1:20, and 1:30 g/mL) on total phenolic content (TPC) were investigated. Effects of different powers (50 % and 80 %) were also studied for ultrasound-assisted extraction. In microwave-assisted extraction, the optimum TPC of the extracts (24.64 ± 2.36 mg GAE/g dry material) was obtained in 10 min and at 1:30 solid to solvent ratio. For ultrasound-assisted extraction, the condition that gave the highest TPC (23.86 ± 1.92 mg GAE/g dry material) was 30 min, 1:30 solid to solvent ratio, and 80 % power. Extracts obtained at the optimum conditions of microwave and ultrasound were compared in terms of TPC, antioxidant activity (AA) and concentration of phenolic acids with conventional extraction and maceration, respectively. Microwave reduced extraction time by 67 %. AA of extracts varied between 2.95 ± 0.01 and 4.48 ± 0.03 mg DPPH/g dry material among four methods. Major phenolic compounds were determined as naringenin and chlorogenic acid in nettle.
... In addition, since ultrasound is a nonthermal process, thermal decomposition of heat-sensitive compounds is avoided (Ma et al. 2008). Ultrasound extractions of phenolic compounds and antioxidants from citrus (Ma et al. 2008;Londono et al. 2010), grape seeds (Ghafoor et al. 2009), pomegranate seed (Abbasi et al. 2008), strawberry (Herrera and Castro 2004), vanillin from vanilla pods (Jadhav et al. 2009), isoflavonoids from Pueraria (Hu et al. 2008), and oil from tea seeds (Shalmashi 2009) were studied by various researchers. ...
... Therefore, 20 min was chosen as the best extraction time. A similar trend in the relation of TPC and time has also been observed in other extraction studies (Chemat et al. 2004c;Shalmashi 2009). ...
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In this study, extraction of phenolic compounds from melissa by microwave and ultrasound was studied. In both the microwave and ultrasound extractions, the effects of extraction time (5-20 min for microwave; 5-30 min for ultrasound) and solid-to-solvent ratio (1:10, 1:20, and 1:30 g mL(-1)) on total phenolic content (TPC) were investigated. Effects of different powers (50% and 80%) were also studied for the ultrasound extraction. As a solvent, water was used. In microwave extractions, the highest TPC of extracts (145.8 mg GAE g(-1) dry material) was obtained in 5 mm and at a 1:30 solid-to-solvent ratio. For ultrasound extraction, the conditions that gave the highest TPC (105.5 mg GAE g(-1) dry material) were 20 min with a 1:30 solid-to-solvent ratio at 50% power. Extracts obtained at the optimum conditions of microwave and ultrasound were compared with conventional extraction and maceration, respectively TPC and antioxidant activity of the extract was the highest in microwave extraction among all extraction methods. In addition, microwave reduced extraction time by 83%.
... In the meantime, development in high-intensity ultrasound technology has increased its use in several industries (Abdullah and Koc, 2013). Ultrasound-assisted extraction (UAE) is a solvent extraction technique that has been widely studied and it can enhance the extraction effi ciency by reducing the extraction time, as well as the energy and solvent consumption (Fang et al., 2014;Goula, 2013;Shalmashi, 2009). Extraction enhancement by ultrasound can be attributed to the propagation of ultrasound pressure waves and resulting cavitation forces, where bubbles can explosively collapse and generate localized pressure causing ruptures in the plant tissue and improving the release of intracellular substances into the solvent (Goula, 2013;Knorr et al., 2002). ...
... They concluded that the use of a high intensity ultrasound in oil extraction processes reduced the oil extraction time by enhancing the oil extraction rates during the diff usion stage. Some studies also found that UAE requires a signifi cant shorter time and reduced solvent consumption (Shalmashi, 2009;Zhang et al., 2008). In the study of Zen-Shan Zhang et al (Zhang et al., 2008), the extraction yields of fl axseed oil increased with the increase of ultrasonic power and decreased as the temperature was increased. ...
... As reported by Hemwimol et al. [22] an explanation of this is that the larger the amplitude of ultrasonic wave traveling through the liquid medium, the more violently the bubbles collapse enhancing cell tissues disruption and so improving the extraction efficiency. Similar behaviours were reported for the ultrasound-assisted extraction of oil from flaxseed [23] and tea seeds[24]. The higher oil recovery of S (14.64% w/w) can be ascribed to the fact that seed tissues were continuously extracted with fresh condensed solvent for 6 h, while US were conduced in a batch system for 30 min. ...
Article
Full-text available
Ultrasound-assisted extraction (US) carried out at 20KHz, 150W for 30min gave grape seed oil yield (14% w/w) similar to Soxhlet extraction (S) for 6h. No significant differences for the major fatty acids was observed in oils extracted by S and US at 150W. Instead, K(232) and K(268) of US- oils resulted lower than S-oil. From grape seeds differently defatted (S and US), polyphenols and their fractions were extracted by maceration for 12h and by ultrasound-assisted extraction for 15min. Sonication time was optimized after kinetics study on polyphenols extraction. Grape seed extracts obtained from seeds defatted by ultrasound (US) and then extracted by maceration resulted the highest in polyphenol concentration (105.20mg GAE/g flour) and antioxidant activity (109Eq αToc/g flour).
... Thus, the continuously increase of ultrasonic time would not change much of the oil yield. Similar results have also been shown in the studies of ultrasound-assisted extraction of oil from flaxseed (Zhang et al., 2008), tea seed (Shalmashi, 2009), and saikosaponins from radix bupleuri (Zhao et al., 2007). Zhang et al., Shalmashi et al., and Zhao et al. found that the oil yield was increased with increasing the ultrasonic time, and the increase was then stayed same when sonication was prolonged. ...
Article
In the present study the effects of ultrasonic pretreatment and the types of enzyme on oil yield were investigated. The optimum ultrasonic pretreatment parameters were found to be 250W of ultrasonic power, 30min of ultrasonic time, and 50 degrees C of ultrasonic temperature. Five types of enzyme, Cellulase, Viscozyme L, Alcalase 2.4L, Protex 6L, and Protex 7L, were evaluated for their effectiveness in releasing oil from ultrasonic pretreated perilla seeds. The highest oil yield of 81.74% was observed in cellulase treated perilla seed samples. The physicochemical properties of the control, hexane, and enzyme extracted perilla seed oils were compared. No significant (P>0.05) differences were observed in iodine value, refractive index, unsaponifiable matter, saponification value, peroxide value, and acid value. En el presente estudio se investigaron los efectos del pretratamiento ultrasonico y tipos de enzima en el rendimiento de aceite. Los parametros optimos de pretratamiento de ultrasonidos fueron 250W de potencia ultrasonica, 30min de tiempo de ultrasonidos, y 50 degrees C de temperatura de ultrasonidos. Cinco tipos de enzima, celulasa, Viscozyme L, Alcalase 2.4L, Protex 6L, y 7L Protex, fueron evaluados por su eficacia en la liberacion de aceite de semillas de perilla pretratadas con ultrasonicos. El mayor rendimiento de aceite de 81,74% se observo en las muestras de semillas de perilla tratadas con celulasa. Se compararon las propiedades fisicoquimicas del control y de aceites de semillas de perilla extraidas con hexano y enzimas. No se observaron diferencias significativas (P >0,05) en el indice de yodo, indice de refraccion, la materia insaponificable, valor de saponificacion, el valor de peroxido y el valor acido.
... The larger the amplitude of ultrasonic wave travelling through the liquid medium, the more violently the bubbles collapsed, increasing seaweed tissue disruption and thus improving extraction efficiency (21). Similar behavior was reported for UAE of polyphenols from pomegranate peel (22), oil from flaxseed (23), and tea seeds (24). Solvent type had a strong effect on the concentrations of targeted bioactive compounds obtained. ...
Article
The work investigates the application of ultrasound for improved extraction of bioactive compounds namely total phenolics, fucose, and uronic acid from brown seaweed (Ascophyllum nodosum). Key process parameters of ultrasonic intensity (UI), extraction time, and solvent type were investigated to optimize extraction yields. The maximum yields on dry basis (db) of total phenolics, fucose, and uronic acid were 82.70 mg GAE/gdb, 135.76 mg/gdb, and 197.19 mg/gdb, respectively. Maximum bioactive yields were obtained using 0.03 M HCl as solvent at an UI of 75.78 W cm−2. Extraction kinetics over a 22 hour period were successfully modelled using Peleg’s model. This extraction kinetic study demonstrates that ultrasound pretreatment can significantly enhance extraction of bioactives from brown seaweed.
... The microencapsulated kenaf seed oil (MKSO) was reported to possess abundant of bioactive compounds and unsaturated fatty acids even after spray drying process [10] . Recently, numerous attempts to replace solvent extraction have been made, of which ultrasonic-assisted extraction (UAE) is one of the most promising methods [11][12][13] . This could be related to its improvements in efficiency and speed, which can be performed at low operation temperatures. ...
Article
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To determine the antihypercholesterolemic effects of kenaf seed samples and compare with the commercial hypocholesterolemic drug on serum lipids profiles and malondialdehyde (MDA) level in the rat. Kenaf seed oil (KSO), microencapsulated kenaf seed oil (MKSO), kenaf seed extract (KSE) and defatted kenaf seed meal (DKSM) were prepared and phytochemicals screening on these samples were done prior in vivo study. Phenolic compounds in KSE were quantified using high performance liquid chromatography. There were 40 (divided in eight diet groups of 5) male Sprague dawley rats adapted to normal standard diet or hypercholesterolemic diet (HD) with or without the treatment of these kenaf samples for 32 days. All the kenaf samples exhibited to contain most of the major phytochemicals. KSE possessed gallic acid, tannic acid, catechin, benzaldehyde, benzoic acid, syringic acid, sinapic acid, ferulic acid, naringin acid, and protocatechuic acid. The significant higher (P<0.05) serum total cholesterol, low density lipoprotein cholesterol and MDA levels in HD group without treatment than the normal control group suggested the hypercholesterolemia was induced by the incorporation of cholesterol into diet. KSE exhibited higher cholesterol-lowering properties due to the significant lower (P<0.05) in serum triglycerides, total cholesterol and MDA levels. KSE showed the highest efficiency of cholesterol-lowering activity, followed by KSO, MKSO and DKSM. DKSM, MKSO, KSO and KSE appeared to have comparable anti-hypercholesterolemic effect with the commercial hypocholesterolemic drug. Hence, kenaf seed could be used as an alternative natural source to replace the synthetic hypocholesterolemic drugs. Copyright © 2015 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.
... Therefore, the extraction efficiency increases (Kadam et al. 2015;Zhang et al. 2008). The similar results were also reported by Lou et al. (2010) and Shalmashi (2009). Different researches have been performed on the optimization of oil extraction from oil seeds with the use of response surface methodology (Rostami et al. 2014). ...
Article
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In the current study, response surface optimization of Canola oil extraction assisted by 35 kHz, 800 w ultrasound waves, and with the use of hexane and 3:2 hexane–isopropanol with the proportion of 3/2 as solvents was conducted. The influence of extraction temperature (35, 45 and 55 ℃), ultrasound treatment time (30, 60 and 90 min) and solvent to Canola (sample) ratio (5, 10 and 15 (%v/w)) on the percentage of the extracted oil and oxidative stability of the extracted oil were analyzed through Box-Behnken Design. The achieved results revealed that the optimized conditions for Canola oil extraction (22.39% efficiency) by hexane was 87 min ultrasound treatment at 55 ℃, and solvent to Canola proportion of 6.39 (%v/w). On the other hand, the optimized conditions for Canola oil extraction (30.66 % efficiency) by hexane-isopropanol mixture was 69.5 min ultrasound treatment at 55 ℃, and solvent to Canola ratio of 9.12 (%v/w). The obtained outcomes revealed that ultrasound waves significantly improved the extraction efficiency compared to Soxhlet extraction. The extraction efficiency was improved when hexane–isopropanol mixture was applied. In optimized condition oxidative stability of the extracted oil has been achieved 12.55 and 40.9 h respectively once hexane and hexane-isopropanol were used as solvents for extraction. Oxidative stability presented considerable enhancement with increase in ultrasound treatment. Extracted oil with the use of mixed solvent (hexaneisopropanol) presented higher value for oxidative stability compared to the extracted oil with the use of hexane as a solvent. Comparison between the ultrasound-assisted and Soxhlet extracted oils with the use of gas chromatography presented no significant difference in their fatty acids profiles. Keywords: Canola; Oil extraction; Ultrasound; Response surface methodology; GC analysis.
... Total phenolic, flavonoid and condensed tannin contents The different extracts obtained by different techniques ME, SE and UAE used for quantification of total phenolic content, flavonoid, and condensed tannins of Phoenix dactylifera L. The results presented in fig. 1 [44] reported similar findings by observing high phenolic content in an extract from Vitis vinifera L. seeds were decreased in the following order: UAE> SE>CE. This high quantity of phytochemicals composition can be related with the larger the amplitude of ultrasonic wave traveling through the liquid medium, the more violently the bubbles collapse enhancing cell tissues disruption and so improving the extraction capacity [45,46]. Metal chelating activity of a sample appears to be particularly important for diseases in which the high levels of metal ions leads to oxidation of proteins and lipids [47].Total phenolic content and metal chelating activity of different extraction techniques were highly correlated, providing strong evidence that the predominant source of antioxidant activity derives from phenolic compounds in wheat. ...
Article
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The present study was designed to quantify the phytochemical composition, evaluation of antioxidant and anti-inflammatory activity of Phoenix dactylifera L leaf extract recovered by ultrasonic-assisted extraction (UAE), Soxhlet extraction (SE) and maceration extraction (CE), which has never been comprehensively investigated before. UAE showed the highest amount of total phenolics (625.17 ± 11.82 mg GAE /g) and revealed significant antioxidant activities (266.12±8.75 μg EDTA/g for the ferrous ion-chelating activity and 78.27±1.26 μg/ml for HOCl). From results, we conclude that there is a strong correlation between phenolic content, antioxidant indicating phenolics are the major compounds for these biological activities. Moreover, similar results observed for the anti-inflammatory activity that the potential of inhibition of nitrite oxide decreased in the following order: UAE> SE>CE. This study shows that Phoenix dactylifera L extracts contain anti-inflammatory and antioxidant substances and should be considered for use in pharmaceutical products for the treatment of several diseases. The advantage of the ultrasound, compared to the Soxhlet extraction and maceration extraction for polyphenols was obtained with a lower solvent consumption and a shorter extraction time
... However, when the temperature exceeded 40°C, the yield of oil exhibited a linear decrease. As temperature increased, the solvent viscosity and density decreased resulting in an increase of mass transfer [16,29,30]. In addition, the number of cavitation bubbles within the fluid increased creating a cohesive force reducing the tensile strength of the liquid as a result of decreased solvent viscosity [15,29,31]. ...
Article
The effectiveness of ultrasonic-assisted extraction (UAE) of pomegranate seed oil (PSO) was evaluated using a variety of solvents. Petroleum ether was the most effective for oil extraction, followed by n-hexane, ethyl acetate, diethyl ether, acetone, and isopropanol. Several variables, such as ultrasonic power, extraction temperature, extraction time, and the ratio of solvent volume and seed weight (S/S ratio) were studied for optimization using response surface methodology (RSM). The highest oil yield, 25.11% (w/w), was obtained using petroleum ether under optimal conditions for ultrasonic power, extraction temperature, extraction time, and S/S ratio at 140W, 40°C, 36min, and 10ml/g, respectively. The PSO yield extracted by UAE was significantly higher than by using Soxhlet extraction (SE; 20.50%) and supercritical fluid extraction (SFE; 15.72%). The fatty acid compositions were significantly different among the PSO extracted by Soxhlet extraction, SFE, and UAE, with punicic acid (>65%) being the most dominant using UAE.
... Electron paramagnetic resonance spectra of free radical captured by spin trap (PBN) sign for grape-seed oil extracted with ultrasound at 25 ∘ C and 60 μm.behavior was reported by Goula, 28 by Shalmashi,29 and by Khoei and Chekin 30 when evaluating oil extraction from pomegranate, tea, and rice bran, respectively. On the other hand, Samaram et al.31 and Hossain et al.8 observed an opposite effect of temperature on the extraction yield of papaya seed oil and marjoram antioxidant compounds, respectively.Regarding the effect of the amplitude of ultrasonic wave on Y, a quadratic negative effect was observed, where increasing amplitude led to the maximum Y up to certain values of A. However, analyzing the results of experiments at 25 ∘ C ...
... Solvent to solid ratio and temperature factors had the greatest influence on the extraction yield. The increase of the yield with the increase of solvent quantity in relation to wood mass is consistent with transfer principles, since the concentration gradient is the driving force for diffusion (Anvar, 2009;Şahin and Şamli, 2013;Zhang et al., 2009). ...
Article
Alpha-Bisabolol is an optically active sesquiterpene applied in various commercial products and obtained at high concentration in essential oil extracted from candeia (Eremanthus erythropappus (DC.) Macleish) wood. In this study, the non-conventional pressurized liquid extraction (PLE) and ultrasound-assisted extraction (UAE) methods were employed to evaluate candeia oil quality in terms of yield and α-bisabolol content in comparison with Soxhlet and hydrodistillation techniques. The extractions with n-hexane, ethanol, and ethyl acetate (Soxhlet and PLE) showed the affinity of the compounds for polar solvents and the positive effect of temperature on the yield. However, the highest purity in terms of α-bisabolol was obtained with the apolar solvent n-hexane (up to 64.23%). Besides the α-bisabolol, α-bisabolol B, and isovaleric acid were found in the composition of the essential oil extracted by hydrodistillation, while the oil extracted with n-hexane also presented the sesquiterpenes eremanthin and costunolide. The UAE was performed using a Box-Behnken experimental design to evaluate the effect of the variables temperature, volume of n-hexane to wood mass ratio, and amplitude percentage on the yield of oil. In 7 min of extraction, up to 83% of the yield obtained in the conventional technique in Soxhlet (360 min) were obtained, with a solvent volume 2.5 times smaller, as well as a high yield of α-bisabolol (up to 8.90 gα-bisabolol kgwood⁻¹).
... In the UAE of tea seed oil, the extraction efficiency increased with an elevation of the time up to 30 min. Nevertheless, it subsequently decreased to 120 min [38]. The extraction duration longer than 70 min caused a reduction in the UAE efficiency of rice bran oil [39]. ...
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Ultrasonic waves cause an increase in oil extraction efficiency through their mechanical effects, cavitation, and the energy generated by this phenomenon. Temperature, time, solvent to sample ratio, solvent type, and ultrasonic power are the most effective factors in the ultrasound-assisted extraction of oils. Temperature increase reduces the surface tension and vapor pressure of the solvent, leading to a rise in the solvent diffusion into the cell, and thus, the extraction efficiency increases. However, as the temperature approaches the solvent boiling point, its vapor pressure rises. Due to the smaller pressure difference between the interior and exterior of the cavitation bubbles, they collapse less intensively and cause the extraction efficiency to decrease. The increase in ultrasonic power has a similar effect on extraction efficiency. An elevation of the extraction time improves this parameter in the early minutes of extraction, by destroying the cell walls and making the oil diffuse out of the cell-matrix. An increase in the solvent to sample ratio up to an optimal level elevates the concentration gradient of the solvent towards the sample matrix by reducing the solution viscosity and brings about an improvement in the extraction efficiency. The application of the solvents with high vapor pressures results in a decrease in the cavitation energy because of the pressure difference between the cell interior and exterior. Therefore, such solvents do not have a positive effect on the extraction efficiency. Each of the aforementioned factors has its optimum level to enhance the ultrasound-assisted extraction efficiency.
... As observed previously, increasing the solvent-tosolid ratio has been agreed to be one of the key factors to promote higher yields from plant materials [38]. Sheng [39] described that cavitational effect from microjets generated from collisions of acoustic bubbles was the trigger mechanism that caused the extensive swelling and disruption of plant cell structures that followed the ultrasonic treatment. ...
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The present study highlighted the statistical modeling of an ultrasonic-aided extraction (UAE) of Elaeis guineensis leaves extract for maximal extraction yield (EY) and total phenolic content (TPC). A Box-Behnken design investigated the effects of ethanol concentration (X1: 0−100%), extraction time (X2: 5−55 min), the solvent-to-solid ratio (X3: 15:1−35:1 mL/g) and sonification amplitude (X4: 20−100 %). Under optimized conditions, the highest EY of 14.38% was attained using 50% (v/v) ethanol:water ratio, 55 min, 35 mL/g solvent-to-solid ratio, 60% sonication amplitude, whereas maximum TPC was 209.70 mg gallic acid equivalent (GAE)/g [50% (v/v) ethanol:water ratio, 30 min, 25 mL/g solvent-to-solid ratio, 60% sonication amplitude]. Second-order polynomial models of EY and TPC showed the R2 value corresponding to 0.9303 and 0.9500, respectively, indicating their significance (p < 0.05) to predict the responses. HPLC chromatograms revealed gallic acid and catechin were present in the UAE extracts. UAE technique afforded better EY (14.38%) and TPC (209.70 mg GAE/g) than maceration (3.73%, 85.23 mg GAE/g) and Soxhlet (6.86%, 102.13 mg GAE/g) extractions, as based on scanning electron micrographs of untreated, UAE, macerated and Soxhlet treated samples. Cell walls of ultrasonic-treated E. guineensis leaves were visibly disrupted to facilitate the higher release of bioactive plant materials, thus justifying the higher EY and TPC. The application of ultrasound appeared to remarkably increase the extraction efficiency of E. guineensis leaves to extract as compared to the conventional methods.
... The viscosity and density of the solvent decreased with increasing temperature (Hemwimol et al., 2006;Ramandi et al., 2012), resulting in an increase in the mass diffusion coefficient (Shalmashi, 2009), causing the easier occurrence of cavitation bubbles, thus reducing the tensile strength of the liquid (Hemwimol et al., 2006). Furthermore, an increase in the vapor pressure of the solutes was observed with the use of higher extraction temperatures, favouring the collapse of the cavitation bubbles in ultrasound-assisted processes (Gutte et al., 2015). ...
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The objective of this work was to evaluate the efficacy of ethyl acetate as a solvent in the extraction of macauba kernel oil (MKO) using ultrasonic-assisted extraction (UAE). It was shown that more MKO oil could be extracted with the use of larger amounts of solvent, higher temperatures and longer extraction times. Thus the maximum oil yield (40.61%) was obtained by UAE at 60 °C for 45 min, using a solvent to kernel ratio of 12 (mL g-1), obtaining a higher yield than that obtained with n-hexane under the same experimental conditions. UAE was favorable for this oil extraction (p < 0.05), presenting a yield close to that reported for classical extraction but with a shorter extraction time and smaller solvent volume. Lauric acid corresponded to ~44% of the MKO composition. The oils presented low free fatty acid contents (<0.80% wt), and the phytosterols, campesterol and β-sitosterol, were identified in the MKO with higher levels in the oil obtained by UAE.
... Thus, the continuously increase of ultrasonic time would not change much of the oil yield. Similar results have also been shown in the studies of ultrasound-assisted extraction of oil from flaxseed (Zhang et al., 2008), tea seed (Shalmashi, 2009), and saikosaponins from radix bupleuri (Zhao et al., 2007). Zhang et al., Shalmashi et al., and Zhao et al. found that the oil yield was increased with increasing the ultrasonic time, and the increase was then stayed same when sonication was prolonged. ...
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In the present study the effects of ultrasonic pretreatment and the types of enzyme on oil yield were investigated. The optimum ultrasonic pretreatment parameters were found to be 250 W of ultrasonic power, 30 min of ultrasonic time, and 50°C of ultrasonic temperature. Five types of enzyme, Cellulase, Viscozyme L, Alcalase 2.4L, Protex 6L, and Protex 7L, were evaluated for their effectiveness in releasing oil from ultrasonic pretreated perilla seeds. The highest oil yield of 81.74% was observed in cellulase treated perilla seed samples. The physicochemical properties of the control, hexane, and enzyme extracted perilla seed oils were compared. No significant (P > 0.05) differences were observed in iodine value, refractive index, unsaponifiable matter, saponification value, peroxide value, and acid value. En el presente estudio se investigaron los efectos del pretratamiento ultrasónico y tipos de enzima en el rendimiento de aceite. Los parámetros óptimos de pretratamiento de ultrasonidos fueron 250 W de potencia ultrasónica, 30 min de tiempo de ultrasonidos, y 50°C de temperatura de ultrasonidos. Cinco tipos de enzima, celulasa, Viscozyme L, Alcalase 2.4L, Protex 6L, y 7L Protex, fueron evaluados por su eficacia en la liberación de aceite de semillas de perilla pretratadas con ultrasónicos. El mayor rendimiento de aceite de 81,74% se observó en las muestras de semillas de perilla tratadas con celulasa. Se compararon las propiedades fisicoquímicas del control y de aceites de semillas de perilla extraidas con hexano y enzimas. No se observaron diferencias significativas (P > 0,05) en el índice de yodo, índice de refracción, la materia insaponificable, valor de saponificación, el valor de peróxido y el valor ácido.
... The possible reason for enhanced lipid content (41 ± 0.24%, w/w) using high power is that larger the amplitude of ultrasonic wave passing through the solvent, more violently the bubbles collapse and enhance the cell disruption, which ultimately enhance the extraction efficiency [34]. Similar studies on enhanced oil recovery with reduced time using high power has been reported in grape seeds [13], flax seeds [35] and tea seeds [36]. ...
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Soaring demand for alternative fuels has been gaining wide interest due to depletion of conventional fuel, increasing petroleum prices and greenhouse gas emissions. Biodiesel, an alternative fuel, derived from oleaginous microbes has been promising because of short incubation time and easy to scale up. Oleaginous yeast Trichosporon sp. is capable of utilizing glycerol and agro-residues for enhanced lipid synthesis. Lipid extraction from Trichosporon sp. biomass showed highest lipid content with ultrasonic assisted extraction (43 ± 0.33%, w/w) coupled with process parameters than the conventional Soxhlet (30 ± 0.28%, w/w) and Binary solvent [choloroform:methanol, (2:1, v/v)] methods (36 ± 0.38%, w/w), respectively. The standardized process parameters of ultrasonic assisted extraction coupled with chloroform/methanol solvent system resulted 95–97% of conversion efficiency in 20 min at 30 °C with a frequency of 50 Hz and 2800 W power, respectively. Enzymatic transesterification of yeast biomass lipid obtained 85% of fatty acid methyl esters that are predominant with oleic acid methyl ester followed by palmitic and stearic acid methyl esters, respectively. These results substantiate that the ultrasonic assisted extraction is a potential green extraction technique that had reduced time, energy and solvent consumption without compromising on lipid quality. Deploying this green extraction technique could make the biodiesel production process inexpensive and eco-friendly.
... This might be due to the reason that increasing the amplitude level increases the agitation of sample and solvent (Santos et al., 2016;Tiwari, 2015) leading to a dispersion of oil from the sample matrix to the solvent phase (Khosravi et al., 2013). Similar behaviour was stated in the ultrasound-assisted extraction of vegetable oil from various oil seeds: tallow olein oil, sunflower, olive and sesame (Hosseini et al., 2015), tea seeds (Shalmashi, 2009), fennel seeds (Khosravi et al., 2013), grape seeds (Da Porto et al., 2013) and papaya seeds (Samaram et al., 2015). From the Fig. 2A, it can be revealed that DPPH activity increases with increasing the amplitude level of ultrasound. ...
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Ultrasound is one of emerging technique’s which is being investigated extremely on food applications and extraction process. In this study, ultrasound-assisted solvent extraction was employed to extract vegetable oil from coriander (Coriandrum sativum L.) seeds. A response surface model was applied to determine the best condition of extraction concerning the independent factors (COY % and DPPH %). In addition, ultrasound variables were the sample solvent ratio, amplitude level, temperature and time. The best condition of extraction was obtained for sample solvent ratio of 1:13 (g/mL), amplitude level of 82 (%), temperature of 45 (°C) and extraction time of 9 (min), being the maximum point of oil yield and antioxidant activity (30.74–72.05%), respectively. Fatty acid profile of oil has been shown as a rich source of petroselinic acid (C18:1)-12, making up 76% of all fatty acids. TGA analyses revealed that 82% (by weight) of oil is thermally stable up to 224 °C.
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Effects of different extraction methods at different conditions on total phenolic content (TPC) of nettle (Urtica diocia) were investigated. Water was used as solvent. TPC analysis was performed according to Folin-Ciocalteu method. In microwave extraction, heating was achieved using microwaves at 407W power level. Effects was obtained as 1:30 solid-to-solvent ratio for 10min. Extraction was also performed conventionally at 1:30 solid-to-solvent ratio for 30min for comparison. There was no significant difference between microwave and conventional extractions with respect to TPC but extraction time was reduced by about 67% in of different solid-to-solvent ratios (1:10, 1:20 and 1:30g/ml) and times (5, 10, 15, and 20min) were studied. The best extraction condition microwave extraction. Extractions using ultrasonic probe were performed in two different power levels (50% and 80% power) at 50% pulser mode and at 40±5°C temperature. Maximum power of ultrasound was 300W. Different solid-to-solvent ratios (1:10, 1:20 and 1:30) and time levels (5, 10, 20, and 30min) were experienced. Solid-to-solvent ratio of 1:30, 30min and 80% power were determined as optimum condition in ultrasonic extraction. Extraction was also performed with maceration using 1:30 solid-tosolvent ratio at 40°C for 24h for comparison. There was no significant difference between ultrasonic extraction and maceration with respect to TPC. TPC of nettle by different extraction methods changed in the range of 19.7- 28.8 mg GAE (Gallic Acid Equivalent)/g dry material. TPC of extracts obtained by microwaves and ultrasound were not significantly different from each other but extraction time was reduced significantly in microwave extraction.
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To optimization of extraction of antioxidant compounds from guava (Psidium guajava L.) leaves and showed that the guava leaves are the potential source of antioxidant compounds. The bioactive polysaccharide compounds of guava leaves (P. guajava L.) were obtained using ultrasonic-assisted extraction. Extraction was carried out according to Box-Behnken central composite design, and independent variables were temperature (20-60°C), time (20-40 min) and power (200-350 W). The extraction process was optimized by using response surface methodology for the highest crude extraction yield of bioactive polysaccharide compounds. The optimal conditions were identified as 55°C, 30 min, and 240 W. 1,1-diphenyl-2-picryl-hydrazyl and hydroxyl free radical scavenging were conducted. The results of quantification showed that the guava leaves are the potential source of antioxidant compounds.
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The study aimed to optimise the ultrasound-assisted aqueous extraction of oil, β-carotene and lycopene from powdered microwave-dried gac arils. Ultrasound power, extraction time, powder particle size and the ratio of water to gac powder during the extraction, the centrifugal force used to recover the extracted components were investigated. Microwave-drying followed by aqueous extraction without ultrasound-assistance and air-drying followed by aqueous extraction with or without ultrasound-assistance was also carried out for comparisons. The gac material left behind after the extractions was also investigated using scanning electron microscopy (SEM). The results showed that ultrasound power of 32 W/g of aril powder, extraction time of 20 min, powder particle sizes of 0.3–0.5 mm, a ratio of water to powder of 9 g/g and a centrifugal force of 6,750
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In this study, ultrasound‐assisted enzymatic technique was investigated using n‐hexane solvent for walnut oil extraction. To achieve this goal, ultrasonic pre‐treatment time (0–70 min) and enzymatic extracting conditions; namely, cellulase concentration (0–2 %) and incubation time (60–240 min) were optimized using response surface methodology. The optimal ultrasonic‐enzymatic extraction treatment using n‐hexane solvent was 47.37 min ultrasonic time, 2.00 % cellulase concentration and 110.91 min incubation time. This treatment resulted in significantly more EY (p≤0.001), TPC (p≤0.001) and IV (p≤0.01) and low level of PV (p≤0.01) of extracted walnut oil, compared to stirring incubation extraction using n‐hexane solvent, ultrasound‐assisted aqueous enzymatic extraction, and aqueous stirring incubation extraction treatments. Gas chromatography–mass spectroscopy showed higher content of unsaturated fatty acids of extracted oil; and scanning electron microscopy showed more pores and interspaces of walnut powder residues of optimal ultrasonic‐enzymatic extraction using n‐hexane solvent than those of stirring incubation treatment using n‐hexane solvent. Practical applications The ultrasonic‐enzymatic technique using n‐hexane solvent can improve the extraction yield, total phenolic content and iodine value of extracted walnut oil. The extracted walnut oil had more poly‐unsaturated fatty acids (linolenic acid and linoleic acid) than that obtained by stirring incubation method using n‐hexane solvent. Thus, the results illustrated that this method was a promising extraction method for more extraction yield of walnut oil with high quality.
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The present study evaluates the suitability of ultrasound pretreatment in n‐hexane solvent as well as enzymatic treatment with cellulase enzyme to extract oil from peanut seed powders. To optimize this process, the effects of ultrasonic time (0–70 min), cellulase enzyme concentration (0–2%) and pH (4–5.5) are investigated on peanut oil extraction yield (EY) as well as the quality attributes of the extracted oil containing total phenolic content (TPC), peroxide value (PV), and color parameters of L, a, and b using response surface methodology (RSM). The optimum condition of ultrasound‐assisted enzymatic extraction using n‐hexane solvent (UAEE) is found as ultrasonic pretreatment time of 33.23 min, cellulase concentration of 1.47%, and pH of 4.61 before incubation process at temperature of 56 °C for 120 min. Scanning electronic microscopy (SEM) represented considerable interspaces, holes, and porous structure of peanut meal after optimal UAEE treatment compared to that after shaking incubation extraction using n‐hexane solvent (SIE). It is found that the peanut oil extracted by optimal UAEE treatment had considerable high levels of L color parameter and TPC and significantly more EY and b color parameters than those extracted by SIE, ultrasound‐assisted aqueous enzymatic extraction (UAAEE), and aqueous shaking incubation extraction (ASIE) treatments. Practical Applications: This paper describes an innovative oil extraction method of ultrasound‐assisted enzymatic process using n‐hexane solvent. This new extraction technique makes it possible to increase the extraction yield, total phenolic content, and yellowness of extracted peanut oil. The results illustrated that ultrasound‐assisted enzymatic extraction using n‐hexane solvent method was a far more efficient extracting technique than the individual shaking incubation extraction using n‐hexane solvent, ultrasound‐ assisted aqueous enzymatic extraction and aqueous shaking incubation extraction treatments and would be a promising alternative for conventional oil extraction techniques. Comparison of two treatments of optimal ultrasound‐enzymatic extraction and individual shaking incubation extraction of oil from peanut seed powders.
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Changes in functional characteristics of cold brewed white tea were quantified in response to high pressure processing (HPP). The multiple functional responses of total phenolic content (TPC), total antioxidant activity (TAA), and total caffeine content (TCC) were optimized using Box–Behnken design. Operational HPP conditions involved the ranges of pressure (300–500 MPa), solid (tea leaves)/liquid (water) ratio (SLR; 1–3%), and brewing time (120–600 s). Tea leaves/water ratio was determined as the most important factor with the highest rate of change per 1% increase in SLR for TPC (645.8 mg/L), TCC (11.48%), and TAA (5.09%). The optimum conditions were achieved using 300 MPa, 2.2% SLR, and 600 s brewing time and resulted in 91.9% TAA, 1949.2 mg/L TPC, and 17.5% TCC. APP appeared to be a promising alternative novel technique to minimize TCC and maximize TAA and TPC of cold brewed white tea simultaneously. Practical applications The present study quantifies the multiple health‐related responses of cold brewed white tea to high pressure processing (HPP). The HPP approach adopted in the study provides cold brewed white tea with good quality and is cost‐effective in terms of small‐to‐large scale food industries. Joint optimization results can be used to improve the operational conditions of cold brewed white tea by related food processors.
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Conventional solvent extraction (CE) and ultrasound‐assisted extraction (UAE) in hexane for oil from untreated and enzyme‐treated grape seeds were investigated and compared. Among the output power tested (50, 100 and 150 W) in UAE on untreated seeds, UAE at 150 W for 30 min with liquid‐to‐solid ratio 8:1 (v/w) gave oil extraction yield comparable to CE (ca. 14% w/w) for 6 h with liquid‐to‐solid ratio 12:1 (v/w). CE and UAE at 150 W did not influence the fatty acid profiles of oil. CE oil was found to be the most oxidised. The enzymatic treatments (2, 4 and 6 g per 100 g seeds of Rapidase® Expression) prior to CE enhanced by 2.5% of the oil yield. Enzymatic treatments higher than 2 g per 100 g seeds increased relative value of some fatty acids both in CE and UAE. Enzymatic pretreatment from 2 to 4 g per 100 g seeds significantly improved some physicochemical parameters of oil quality when extracted by CE, but not by UAE.
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Orthogonal array design (L-9 (3(4))) was applied to optimize the flaxseed oil (FO) recovery, beta- and gamma-tocopherols yields and total oxidation value (totox value) using ultrasound-assisted extraction (UAE). The optimized results were then compared with the one extracted by Soxhlet extraction (S. E.) at 8 h. The results revealed that 80.05% FO can be recovered by extraction for 30 min, 30 degrees C and 10: 1 solvent/solid ratio by UAE compared to 100% recovery obtained by 8 h, 60 degrees C and 20:1 solvent/liquid ratio by S.E. (taken as reference and standard extraction). beta- and gamma-tocopherols yield was 40.39 mg/100 g oil at 30 min, 20 degrees C and 10:1 solvent/liquid ratio by UAE compared to 56.37 mg/100 g oil by S. E. Totox value of FO by UAE was lower compared to S.E., which is a promising results for better quality and further processing of the oil. No significant differences were shown between the two extraction methods for fatty acids (p < 0.025). UAE is capable of reducing the financial cost of flaxseed oil extraction, saving time, energy and is also environmentally friendly since very little solvent is used compared to S.E. Practical applications: Flaxseed oil is an unstable vegetable oil due to its high content of polyunsaturated fatty acids (PUFA), which are mainly composed of alpha linolenic acid (ALA). One effective way to ensure a high quality and low oxidation levels of lipids and lipid containing products is to use efficient and rapid method for the extraction.
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The main objective of this work was to carry out the extraction of antioxidant phenolic compounds from bay leaves (Laurus nobilis L.) through mechanochemical pretreatment (mechanochemical assisted extraction, MCAE). For this purpose, different solid reagents were screened (Na2CO3, BaCO3, Li2CO3, CoCO3, K2CO3 and CaCO3), and the results were compared with other extraction techniques: conventional Soxhlet, ultrasound (UAE) and microwave (MAE). The comparison was carried out based on total dissolved solids (TDS), total phenolic content (TPC) and antioxidant power (AOP). As-obtained extracts were analysed by gas chromatography and gas chromatography-mass spectrometry analysis (GC and GC–MS) to characterize their composition. In conventional Soxhlet extraction different solvents (water, ethanol and methanol) were tested. It was demonstrated that ethanol provided the best results. Mechanochemical processing resulted in comparable TPC (75.54 GAE g−1 extract) to Soxhlet. Therefore, MCAE is a step forward since, for the same TPC as conventional extraction, the total extraction time (mechanochemical pretreatment and extraction in ethanol) is reduced more than 10 times. The main phenolic compounds present in the extracts were identified as eugenol, methyleugenol and elemicin. Although the results obtained by means of UAE and MAE could be better than those of MCAE, the present study proposes the substitution of conventional extraction by mechanochemistry since the same yields were obtained.
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Roselle seeds, a waste biomass of the roselle calyx processing industry, were utilized to recover valuable compounds of oil, vitamin E, and water-soluble saccharides. Firstly, ultrasound-assisted extraction (UAE) and conventional stirring extraction were conducted for saccharide extraction, and the advantage of UAE was confirmed. Secondly, oil, vitamin E, and saccharides extracted from Vietnamese roselle seeds by UAE were analyzed for the first time. Oil of tri-, di-, and mono-glycerides, fatty acids of linoleic-, oleic-, palmitic-, and stearic-acids, vitamin E of γ- and α-tocopherol, and saccharides of sucrose, raffinose, stachyose, etc. were identified, and the amounts of these components were compared with those in other country's roselle seeds. Thirdly, cascade extraction of oil, vitamin E, and saccharides by UAE was investigated with solvents of hexane, hexane:ethyl acetate binary solvent, and water. The results indicated that the order of using solvents was very important for high and selective extraction: the best order to recover oil (almost 100%), vitamin E (95.7%), and saccharides (86.2%) was hexane, and then water.
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Stearic acid-rich A. parviflora oil production has remained conventional over the past years despite its socioeconomic importance. Ultrasonication (ULT), microwave irradiation (MIC), and ultrasound-microwave (hybrid technique, ULT-MIC)-assisted extraction parameters were optimized. Their effects on the physicochemical, antioxidative, and structural properties of A. parviflora oil were evaluated. ULT ensured higher oil yield and extraction efficiency of 64.15% and 92.16%, respectively, with a 33.33% reduction in extraction time over the conventional method. Oil extraction yield with MIC and ULT-MIC were solvent dielectric constant, ε (polarity) dependent. ULT, MIC, and ULT-MIC enhanced the freshness and stability of A. parviflora oil by reducing its acid and peroxide values significantly. MIC produced oil with high total phenol content (226.60 mg Gallic acid equivalents (GAE)/kg). Ultrasonic action had the highest impact on the seed meal structure. A high yield of edible oil that possesses strong antioxidant activity could be obtained by adopting the ULT-MIC hybrid extraction technique with a polar solvent.Graphic abstract
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Present study deals with the extraction of oil from the waste custard apple seed (CAS) using acoustic cavitation. The process parameters such as optimization of irradiation time, temperature, power of ultrasound, different solvents and seed to solvent ratio have been studied. For a comparative study, obtained oil from the acoustic cavitation method was compared with Soxhlet method. When power increases, fall in the extraction yield increases, and with decrease in temperature, the rise in extraction yield was observed. The obtained oil was characterised by the Fourier transformation spectroscopic analysis. The effect of acoustic irradiation on chemical and physical properties of the extracted oil was checked using differential thermal analysis and thermogravimetric analysis and compared with extracted oil by conventional Soxhlet method. The compounds such as oleic acid, palmitic acid and stearic acid in the extracted oil were identified using gas chromatography mass spectroscopy analysis. Scanning electron microscopy had confirmed the cracking and microfractures of the seed surface which are responsible for cell wall disruption. The time required for the extraction oil from the CAS using ultrasound is only 10 min, while Soxhlet method requires 70 °C temperature and 4.5 h (270 min) of time to get the same yield. The amount of energy required for the extraction of the oil from the CAS using acoustic cavitation method is 84.51% less than the Soxhlet method. Acoustic cavitation is a novel, simple and energy efficient method for the extraction of oil from the CAS.
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Ultrasound-assisted extraction was evaluated as a simpler and more effective alternative to conventional extraction methods for the isolation of ginsenosides (saponins) from various types of ginseng. The ginseng samples were extracted with different solvents, under either direct sonication by an ultrasound probe horn or indirect sonication in an ultrasound cleaning bath. The ultrasonic extraction was compared with the conventional method of refluxing boiling solvents in a soxhlet extractor, on the yields of both the total saponin isolated by thin-layer chromatography and the individual ginsenosides by high performance liquid chromatography. It was found that the sonication-assisted extraction of ginseng saponins was about three times faster than the traditional extraction method. The ultrasonic extraction was not only more efficient but also convenient for the recovery and purification of the active ingredients of plant materials. In addition, the sonication-assisted extraction can be carried out at lower temperatures which are favorable for the thermally unstable compounds.
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The antioxidant efficiencies of 5,7,3′,4′-hydroxy-substituted flavonoids were examined. The tested compounds (quercetin, luteolin, taxifolin, (+)-catechin and eriodictyol) were selected with a view to their C-ring differentiated pattern. Each one was added in cottonseed oil at equimolar amounts and the retardation of lipid peroxidation was estimated by means of peroxide value. Furthermore, their ability to scavenge DPPH radical was studied in two solvents (methanol and ethyl acetate) and the DPPH method proved a satisfactory prediction test for the antioxidant action of flavonoids in oils when methanol was used as the reaction media. Furthermore, the comparison of the C-ring structural element contribution to the antioxidant action revealed the full substitution to be the most important followed by the 3-OH and 2,3-double bond in the presence of the 4-carbonyl. Concerning the monosubstituted flavonoids, the 4-carbonyl group induced minor activity, whereas the 3-OH increased significantly the antiradical and antioxidant action.
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Focus on eco-friendly processing techniques makes vegetable tanning a viable option in leather processing and establishes the subsequent need for the more efficient methods of extraction in tannin manufacture. Application of ultrasound has been tried in the extraction of tannins from myrobalan nuts in order to improve the extraction efficiency, to perform the extraction under milder process conditions and to reduce the process time. The influence of process parameters such as ultrasonic output power, time and temperature has been studied. Scale-up trials and the use of ultrasound in pulse mode have also been attempted. The results show that a three- to fivefold improvement is possible with ultrasonic output from 20 to 100 W. Extraction efficiency has been calculated from the maximum extractable materials from myrobalan nuts. Extraction efficiency is found to be 90% for ultrasound, 100 W without external heating as compared to 77% for control process at 70 °C for 4 h. Therefore, ultrasound could be employed even dispensing with provision for temperature controls. The use of ultrasound in pulse mode offered 70% extraction efficiency of continuous mode. Scale-up trials indicate that there exists an optimum ultrasonic output power depending on the amount of nuts used, to achieve better extraction efficiency. The effectiveness of ultrasonically extracted tannin solution has also been tested in the tanning process for its applicability. The degree of tanning efficacy has been assessed by shrinkage temperature measurement. The results indicate that ultrasonically extracted tannin solution is suitable for tanning process. Therefore, application of ultrasound in tannin extract manufacture is a viable option with added advantages.
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Blends of hydrogenated and nonhydrogenated tea seed oil (Lahijan variety) (30:70, w/w) were chemically interesterified at 60, 90, and 120°C for 30, 60, and 90 min in the presence of 1% (w/w) NaOH. Physicochemical properties of the products were compared with those of the noninteresterified mixture. Statistical comparison of m.p., iodine values (IV), and solid fat contents (SFC) showed that the sample having the highest ranking was interesterified at 120°C for 30 min. The sample was used as a hardstock (40%), with liquid tea seed oil and sunflower oil (ratios of 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100) as, a softstock (60%) for production of table magarine, and the properties of these margarines were compared with those of commercial ones. Samples E and D (ratio of 80:20 and 60:40 liquid tea seed oil/sunflower oil, respectively) had the lowest significant differences with commercial table margarine for physicochemical (m.p., IV, and SFC) and organoleptic characteristics, respectively. Generally, based on m.p. and SFC, margarines E and D were classified as soft margarine. The trans FA content of E, D, and commercial margarines were 1.8, 1.8, and 2.2%, respectively.
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A comparison of iodine values showed that the degree of saturation of tea seed oil (Lahjan variety) was intermediate between the oils of sunflowerseed (Fars variety) and olive (Gilezeytoon variety), and the saponification values of these three oils were similar. Tea seed oil consisted of 56% oleic acid (C18∶1), 22% linoleic acid (C18∶2), 0.3% linolenic acid (C18∶3), and therefore, on the basis of oleic acid, occupied a place between sunflower and olive oil. In studies at 63°C, the shelf life of tea seed oil was higher than that of sunflower oil and similar to olive oil. Tea seed oil was found to have a natural antioxidant effect, and it enhanced the shelf life of sunflower oil at a 5% level. In this study, tea seed oil was found to be a stable oil, to have suitable nutritional properties (high-oleic, medium-linoleic, and lowlinolenic acid contents), and to be useful in human foods.
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Ultrasound assisted extraction (UAE) of saikosaponins from Radix Bupleuri (Bupleurum Chinense DC) was studied. The effects of various factors such as time (t), temperature (T), ultrasound power (I), particle size (S), solvent to solid ratio (R) and solvent concentration (C) on the yield of target components were investigated. The experimental results indicated that the extraction by UAE is six times faster than those by conventional thermal extraction. It is also found that fast extraction rate was obtained in the first 30 min of sonication. Prolonged sonication did not give a proportional increase in the yield. For the effect of ultrasound power, the maximum yield was obtained at the power level of around 21 W. Scanning electron microscope (SEM) images of the plant cells after UAE treatment were obtained to provide visual evidence of the sonication effect. The effects of particle size, solvent to solid ratio and solvent concentration on the yield are also discussed. The preliminary optimum conditions for UAE of saikosaponins were found at time of 30 min, temperature of 80 °C, power of 21 W, particle size <0.3 mm, solvent to solid ratio of 25 ml/g and solvent concentration of 50%.
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The application of 20 kHz high-intensity ultrasound during extraction of oil from two varieties of soybeans (TN 96-58 and N 98-4573) using hexane, isopropanol and a 3:2 hexane–isopropanol mixture was evaluated. In a simplified extraction procedure, ground soybeans were added to solvents and ultrasonicated between 0 and 3 h at ultrasonic intensity levels ranging from 16.4 to 47.6 W/cm2. Oil was recovered after distillation and yield and composition determined. Using hexane as a solvent, yield generally increased as both application time and intensity of ultrasound increased. Solvent type influenced the efficiency of the extraction, i.e., the highest yield was obtained using ultrasound in combination with the mixed solvent. Gas chromatography analysis of ultrasonicated soybean oil did not show significant changes in fatty acid composition. Results were attributed to mechanical effects due to ultrasonically induced cavitation increasing permeability of plant tissues. A comparison of scanning electron microscopy images of raw and ultrasonicated soybeans indicated development of microfractures and disruption of cell walls in ground soybean flakes. Our study suggests that high-intensity ultrasound may reduce time required to extract edible oils from plant sources and hence improve throughput in commercial oil production processes.
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Efficiency in extracting four isoflavone derivatives (daidzin, glycitin, genistin and malonyl genistin) from freeze-dried ground soybeans was compared for mix-stirring extraction and ultrasound-assisted extraction, using different solvents and extraction temperatures with both. The efficiency of the extraction of soy isoflavones was improved by ultrasound but was dependent on the solvent employed. Optimization of the ratios of sample quantity to solvent volume and length of extraction time was also performed. Isoflavones can be quantitatively extracted from soybeans with 50% ethanol at 60 degrees C using ultrasound-assisted extraction in 20 min.
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Conventional Soxhlet extraction assisted in the cartridge by ultrasound has been developed and used to extract the total fat content from oleaginous seeds such as sunflower, rape and soybean seeds. The application of ultrasound to the sample cartridge enormously decreases the number of Soxhlet extraction cycles needed for quantitative extraction of the fat, thus reducing the extraction time at least to half the time needed by the conventional procedures. The results agree well with those obtained by conventional Soxhlet extraction and the ISO reference method, both in terms of efficiency and precision. The repeatability of the proposed approach, expressed as relative standard deviation, was 0.9%; the within-laboratory reproducibility was 1.3%. Qualitative analysis of the extracted fat showed that the application of ultrasound does not change the composition of the oil.
Article
The effects of high power ultrasound treatment (20 kHz) on some components of refined sunflower oil were studied in order to verify if and to what extent modifications in the lipidic fraction can occur. Traditional parameters including free acidity, total polar compounds, peroxide value, and conjugated dienes concentration were determined in refined sunflower oil samples before, immediately after the ultrasonic treatment and during storage. Differences between treated and untreated samples were detected only for peroxide values (PV). The PV increased from 5.38 meq. O2/kg oil for untreated oil to 6.33 meq. O2/kg oil for sunflower oil sonicated (20 kHz; 150 W; 2 min). The fatty acid composition was obtained by high resolution gas chromatography. No significant changes were observed regarding the decrease in fatty acid composition before and immediately after the treatment. Regarding the volatile fraction, some off-flavour compounds for example hexanal and limonene resulting from the ultrasonic degradation of sunflower oil were identified by gas chromatography coupled to mass spectrometry (GC-MS).
Article
This study investigated the use of ultrasound-assisted extraction (UAE) to improve the extraction efficiency of the classical solvent extraction techniques such as maceration and soxhlet extraction to extract anti-oxidant activity compounds, anthraquinones, from the root of Morinda citrifolia. The effects of different extraction conditions were determined, i.e., temperature of (25, 45, 60 degrees C), ultrasonic power, solvent types, and compositions of ethanol in ethanol-water mixtures. The results show that the yield increases with increasing extraction times and extraction temperatures. The percent recovery of anthraquinones using ultrasound was found to be highly dependent on the type of solvents (acetone > acetonitrile > methanol > ethanol). Furthermore, the use of ethanol-water solution as extraction solvent increased the yield of anthraquinones due to the relative polarity, the swelling effect of plant tissue matrix by water, and increased sound absorption. To achieve the same recovery as that achieved by UAE, soxhlet extraction and maceration required much longer time.
Article
This work examines the concurrent use of power ultrasound during the extraction of pungent compounds from a typical herb (ginger) with supercritical CO(2). A power ultrasonic transducer with an operating frequency of 20 kHz is connected to an extraction vessel and the extraction of gingerols from freeze-dried ginger particles (4-8 mm) is monitored. In the presence of ultrasound, we find that both the extraction rate and the yield increase. The higher extraction rate is attributed to disruption of the cell structures and an increase in the accessibility of the solvent to the internal particle structure, which enhances the intra-particle diffusivity. While cavitation would readily account for such enhancement in ambient processes, the absence of phase boundaries should exclude such phenomena above the critical point. Possible alternate mechanisms for the cell structure damage are discussed.