KINETICS OF ULTRASOUND ASSISTED EXTRACTION OF WEDELOLACTONE FROM Eclipta alba

Charpe, Trupti W.; Rathod, Virendra K.

doi:10.1590/0104-6632.20160334s20140234

Cited by 35 publications

(19 citation statements)

References 12 publications

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“…In particular, at pH 1.5 and after 30 min of extraction, the acoustic extraction rates were 2.3‐fold (US1) and 2.8‐fold (US2) higher than in the conventional extraction. When US density power increases, larger amplitude waves are generated throughout the solvent, resulting in the formation of a considerable number of bubbles which may collapse, accelerating the mass transfer rate …”

Section: Resultssupporting

confidence: 93%

Effects of acoustic power and pH on pectin‐enriched extracts obtained from citrus by‐products. Modelling of the extraction process

et al. 2019

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BACKGROUND The ultrasound‐assisted extraction of pectic polysaccharides from orange by‐products was investigated. Kinetics of mechanical agitation (0.2 × g) and acoustic (US1: 542 W L−1 and US2: 794 W L−1) extractions, were obtained and modelled at different pH values (1.5 and 2.0). All extractions were carried out at 25 °C, using citric acid as the extraction solvent. RESULTS Higher pectic polysaccharides extraction yields were obtained with ultrasonic assistance, in comparison with the results obtained using mechanical agitation. Moreover, yield increases were significantly higher using the more acidic pH. Thus, at pH 1.5, pectin yield increased from ∼19%, obtained with agitation, to ∼47%, applying ultrasound; whereas, at pH 2.0, this increase was from ∼10%, with agitation, to ∼18%, applying ultrasound. A considerable decrease of the galacturonic acid proportion was observed on the extracts when ultrasound were applied for 60 min under pH 2.0. High methoxyl pectins were extracted at pH 1.5 whereas at pH 2.0, pectins exhibited a low methylation degree. Curves of acoustic and mechanical agitation extractions were properly represented by a second‐order rate model (average mean relative error ≤ 7.4%). The extraction rate constant, initial extraction rate and maximum yield were determined for all experimental conditions. CONCLUSION Overall, the results clearly indicated that the effect of ultrasound was highly dependent on the pH. Therefore, adequate acidic conditions must be applied in order to improve the efficiency of ultrasound on the pectin extraction process. © 2019 Society of Chemical Industry

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Section: Resultssupporting

confidence: 93%

Effects of acoustic power and pH on pectin‐enriched extracts obtained from citrus by‐products. Modelling of the extraction process

et al. 2019

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“…3) shows the data that when the ethanol concentration increases, the concentration of flavonoids increases too. These results partly confirm the results obtained by Charpe [11], however, contradict V. Kothari et al [7], who claimed that extraction of medicinal plant materials should be done using 70% aqueous ethanol solutions. In this experiment, the highest value of the total concentration of flavonoids was reached by using 96% ethanol (0.418%), and the lowest by using 50% AES (0.062%).…”

Section: Resultssupporting

confidence: 88%

The influence of extraction method and conditions on the concentration of flavonoids in the extracts of rowanberries

Vaškelienė¹,

Šlinkšienė²

2019

chemija

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For the extraction, rowanberries (collected in 2017 and 2018) and aqueous solutions of various concentrations of ethanol (50%, 60%, 70%, 80% and 96%) in a ratio of 1:10 were used. Different types of extraction methods (extraction under static conditions, Soxhlet extraction and ultrasound assisted extraction) were tested. Using different types of extraction methods, it was found that irrespective of the method chosen when the concentration of ethanol increases, the concentration of total flavonoids also increases. Using collected rowanberries in 2017, the highest and similar numerical value of the concentration of total flavonoids was reached when an ultrasound bath was used 20 min for extraction (0.512%) using a magnetic stirrer for 90 min (0.498%). In both cases, a 96% aqueous ethanol solution was used. The highest total concentration of flavonoids in the extracts of rowanberries collected in 2018, obtained under static extraction conditions, using a 96% aqueous ethanol solution, was 0.525%, in 2017 it was 0.418%.

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“…The reason might be, firstly, the polarity of methanol–water mixture was more similar with phenolics of the extracts than the polarity of water (Rodrigues et al, ). Thus, the solubility of phenolics is higher in the mixture than in water; Secondly, a solvent that has high surface tension and high viscosity probably has an increased energy barrier for the cavities which has negative affect on cavitation (Charpe & Rathod, ). Therefore, the higher extractability obtained by the methanol–water mixture was possibly because of its polarity, as well as lower viscosity and lower surface tension than water.…”

Section: Resultsmentioning

confidence: 99%

Ultrasound‐assisted extraction (UAE) of bioactive compounds from coffee silverskin: Impact on phenolic content, antioxidant activity, and morphological characteristics

Wen

Zhang

Rai

et al. 2019

J Food Process Engineering

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Coffee silverskin (CSS) has various nutritional and functional properties, enabling it for valuable applications. Ultrasound‐assisted extraction (UAE) is an efficient and economic extraction technique. In this research, UAE was employed in the extraction of bioactive compounds from CSS with water and methanol–water mixture as solvent. Extraction efficacy between the UAE‐treated extracts and the UAE‐untreated (control) was assessed in terms of the total phenolic content (TPC), caffeine content, chlorogenic acids (CGAs), and antioxidant capacities. The yields of TPC were in the range from 5.80 ± 0.06 to 8.94 ± 0.01 mg GAE/g sample. Phenolic content and antioxidant activity were highly enhanced by applying UAE compared to the controls. Noticeable caffeine content in the range from 3.27 ± 0.10 to 4.29 ± 0.01 g/100 g sample was found in the CSS samples. CGAs (3‐CGA, 4‐CGA, and 5‐CGA) were all quantified. Methanol–water extracts showed significantly (p < .05) higher TPC, caffeine content, and antioxidant capacity than water extracts. The micro‐structure investigation of CSS indicated UAE can cause cell disruption and micro cracks so that it can be an effective extraction technique. Peleg's model showed a good fitting (R2 > 0.94) to the experimental results on the kinetics of UAE of phenolics compounds. Practical applications Coffee is a most consumed beverage internationally. Due to its great production, large quantities of residues including coffee pulp and husk, coffee silver skin, and spent coffee grounds are generated in the coffee industry. Among them, coffee silverskin (CSS) is a by‐product during the coffee roasting process, which contains nutritional and functional properties. As an efficient and economic novel extraction technique, ultrasound‐assisted extraction (UAE) was employed in the current study to extract bioactive compounds from coffee silverskin with water and methanol–water mixture as solvent in order to overcome various disadvantages encountered by the conventional extraction methods. Results indicated that application of UAE pretreatment showed significantly higher recovery of phenolic compounds compared to the controls and high ultrasound intensity (38 W/cm2) was more effective in recovering polyphenols compared to 5 W/cm2 ultrasonic treatments. Therefore, results from the current study provide useful and practical information for the coffee industry.

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KINETICS OF ULTRASOUND ASSISTED EXTRACTION OF WEDELOLACTONE FROM Eclipta alba

Cited by 35 publications

References 12 publications

Effects of acoustic power and pH on pectin‐enriched extracts obtained from citrus by‐products. Modelling of the extraction process

Effects of acoustic power and pH on pectin‐enriched extracts obtained from citrus by‐products. Modelling of the extraction process

The influence of extraction method and conditions on the concentration of flavonoids in the extracts of rowanberries

Ultrasound‐assisted extraction (UAE) of bioactive compounds from coffee silverskin: Impact on phenolic content, antioxidant activity, and morphological characteristics

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