Optimizing a sustainable ultrasound assisted extraction method for the recovery of polyphenols from lemon by-products:comparison with hot water and organic solvent extractions

Response surface methodology (RSM) based on a three-factor and three-level Box–Behnken design was employed for optimizing the aqueous ultrasound-assisted extraction (AUAE) conditions, including extraction time (35–45 min), extraction temperature (45–55 °C) and ultrasonic power (150–250 W), for the recovery of total phenolic content (TPC) and rutin from lemon by-products. The independent variables and their values were selected on the basis of preliminary experiments, where the effects of five extraction parameters (particle size, extraction time and temperature, ultrasonic power and sample-to-solvent ratio) on TPC and rutin extraction yields were investigated. The yields of TPC and rutin were studied using a second-order polynomial equation. The optimum AUAE conditions for TPC were extraction time of 45 min, extraction temperature of 50 °C and ultrasonic power of 250 W with a predicted value of 18.10 ± 0.24 mg GAE/g dw, while the optimum AUAE conditions for rutin were extraction time of 35 min, extraction temperature of 48 °C and ultrasonic power of 150W with a predicted value of 3.20 ± 0.12 mg/g dw. The extracts obtained at the optimum AUAE conditions were compared with those obtained by a hot water and an organic solvent conventional extraction in terms of TPC, total flavonoid content (TF) and antioxidant capacity. The extracts obtained by AUAE had the same TPC, TF and ferric reducing antioxidant power as those achieved by organic solvent conventional extraction. However, hot water extraction led to extracts with the highest flavonoid content and antioxidant capacity. Scanning electron microscopy analysis showed that all the extraction methods led to cell damage to varying extents

Assessment of mortar evolution in pig slurry by mechanical and ultrasonic measurements

This work presents the results obtained in a long-term experiment focused on the study of the evolution of cementitious materials immersed in pig slurry at real conditions. Cement mortars were made with four different cement types and immersed in pig slurry for 48 months. Furthermore, to separate pure hydration process from pig slurry effect, mortar samples were immersed in water for 12 months at laboratory conditions. Compressive strength, X-ray diffraction and ultrasonic measurements were made in all samples. Ultrasonic measurements were made from ultrasonic images obtained from automatic ultrasonic inspections. Use of ultrasonic images has allowed the extraction of information about the state of the studied materials. An empirical relationship between ultrasonic velocity and compressive strength has been obtained and the long-term effect of pig slurry on cementitious materials has been determined

Study on the extraction of dioscin by the ultrasonicassisted ethanol

With Dioscorea zingiberensis as row materials, and with the yield of diosgenin as assessment criteria, the effect on extraction yield of dioscin of frequency of ultrasonic, the period of ultrasonic and solidliquid ratio (D. zingiberensis : alcohol) was studied via orthogonal test. A new and unique method to accomplish this was by utilizing the technology of ultrasonic assisted ethanol extraction. The optimal processing parameters of this method were confirmed. The method was compared with solvent extraction process for the effect on extraction yield of dioscin. It was shown that the technology of ultrasonic assisted ethanol extraction which can significantly increase the extraction yield and extraction efficiency of dioscin. The ultrasonic did not destroy D. zingiberensis cell structure, but decreased the boundary layer thickness between D. zingiberensis (solid phase) and alcohol (medium), and accelerated cells inside and outside the material exchange. International rectifier (IR) further demonstrated that ultrasonic merely increased extraction yield of dioscin instead of destroying the cell structure.Keywords: D. zingiberensis, ultrasonic waves, extraction, diosgenin

Comparison of extraction methods for analysis of flavonoids in onions

Onions are known to contain high levels of flavonoids and a comparison of the efficiency, reproducibility and detection limits of various extraction methods has been made in order to develop fast and reliable analytical methods for analysis of flavonoids in onions. Conventional and classical methods are time- and solvent-consuming and the presence of light and oxygen during sample preparation facilitate degradation reactions. Thus, classical methods were compared with microwave (irradiation) extraction, ultrasonic liquid extraction and accelerated solvent extraction

GC-MS Analysis of Lemongrass with Various Extraction Methods

Lemongrass (Cymbopogon citratus) is one plant producing bioactive essential oil. This research aims to determine the percentage yield of extracts and GC-MS analysis of chemical compound profiles of lemon grass with various extraction methods. Lemongrass bioactive compounds are extracted using maceration, ultrasonic, and distillation. The highest percentage extract yield was from maceration extraction, namely 14.83%, ultrasonic extraction was 4.68%, and distillation extraction was 6.00%. The GC-MS results showed that the secondary metabolite compounds resulting from maceration, ultrasonic, and distillation contained geraniol, citronellal, and citronellol. The citronella compound group was obtained with the highest percentage from distillation extraction at 14.83%, followed by ultrasonic extraction at 2.23% and maceration extraction at 0.37%

Application of Orthogonal Design to Optimize Extraction of Polysaccharide from Cynomorium songaricum Rupr (Cynomoriaceae)

Purpose: To optimize the extraction technology of polysaccharides from Cynomorium songaricum Rupr by ultrasonic-assisted extraction (UAE).Methods: Four parameters including ultrasonic power, ratio of raw material to water, extraction temperature, and extraction time were optimized by orthogonal design. The effects of the factors on the yield of polysaccharides were also studied. The hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were determined in vitro by spectrophotometry.Results: The optimal conditions were as follows: 1:30 as ratio of raw material to water, extraction for 70 min at 80oC with ultrasonic power being 420 W. Under these conditions, the yield of polysaccharides was up to 4.51%, which was significantly higher than that obtained under the initial conditions (3.82 %). DPPH radical scavenging activity reached 64.82 % at 0.012 mg/mL, while hydroxyl radical scavenging activity was 18.36 % at 0.5 mg/mL.Conclusion: Ultrasonic-assisted extraction technology is a useful tool for the extraction of bioactive components from biological materials.Keywords: Cynomorium songaricum, Polysaccharide, Ultrasonic-assisted Extraction, Orthogonal Desig

EXTRACTION OF POLYSACCHARIDES FROM LINGZHI BY ULTRASONIC-ASSISTED ENZYMATIC METHOD

The medicinal values of polysaccharides (PS) in Lingzhi have been shown to lie in many anti-cancer effects and good benefits for human health. Lingzhi, which is rich in healthy PS, has been used more and more commonly in Vietnam in recent years. In the present work, ultrasonic-assisted enzymatic extraction (UAEE) was used for extraction of PS from Lingzhi. The experiments were conducted according to a Box-Behnken design (BBD), with four independent variables: solvent temperature, ultrasonic power, pH, and ultrasonic irradiation time. The results showed that the best adequate extraction conditions were extraction time of 144 min, extraction temperature of 55°C, ultrasonic power of 240W, pH 7.9, and ultrasonic irradiation time of 144 min. Under these conditions, the predicted optimal yield was 3.716%. Whereas by following the optimized conditions, the experimental yield of PS was 3.65% ± 0.14, which was in good agreement with that of the prediction. Compared to the hot water extraction (HWE) method, ultrasonic-assisted extraction (UAE) method and enzyme-assisted extraction (EAE) method, the yield of PS obtained by UAEE was favorable. The PS yield obtained by HWE, and EAE were 1.96% and 3.10%, respectively. These results demonstrated that UAEE was an appropriate and effective extraction of polysaccharides from Lingzhi

Effects of ultrasonic treatments on the polyphenol and antioxidant content of spinach extracts

The objective was to test ultrasound treatments on spinach leaves during extraction, and conventional extraction was used as a control. The effects of different combinations of the ultrasonic water bath factors tested on phenolic compound yields included frequency (37 and 80 kHz), exposure time (5, 10, 15, 20, 25 and 30 min), temperature (30, 40, and 50 C), and ultrasonic power (30%, 50%, and 70%). The best conditions for extraction yields were ultrasonic frequency of 37 kHz, extraction time of 30 min, reaction temperature of 40 C, and ultrasonic power of 50%. The mean yield (mg/100 g), total phenol (mg gallic acid/g DW), flavonoids (mg/g DW), % DPPH free-radical scavenging activity, and % ferric reducing antioxidant power were all high (64.88 ± 21.84, 33.96 ± 11.30, 27.37 ± 11.85, 64.18 ± 16.69 and 70.25 ± 9.68). Treatments were significantly different. The interaction among the ultrasonic parameters was significant. Temperature and power had significant effects on all other dependent variables

Screening the effect of four ultrasound-assisted extraction parameters on hesperidin and phenolic acid content of aqueous citrus pomace extracts

Polyphenols of citrus by-products, due to their antioxidant and antimicrobial activities, could be valorized by pharmaceutical and food industries, adding a value to the citrus processing companies. A number of studies have investigated the effect of ultrasound-assisted extraction (UAE) conditions on the recovery of phenolics derived from citrus waste using both organic solvents or mixed aqueous solvent systems. To maximize efficiency, UAE conditions should be tailored to the physical parameters of the solvent(s) employed. The aim of this study was to investigate the effect of four UAE parameters: particle size (1.40–2.80 mm), extraction time (10–60 min), extraction temperature (23–50 °C) and ultrasonic power (150–250 W) on the simultaneous recovery of p-coumaric acid, caffeic acid, chlorogenic acid, and hesperidin from citrus waste using pure water as a solvent. High-performance liquid chromatography (HPLC) was employed for the identification and quantification of the cited compounds. Particle size was determined to be an important parameter affecting compound recovery, with the exception of chlorogenic acid. A particle size of 1.40 mm resulted in the highest recovery of p-coumaric and caffeic acids (0.25 and 0.58 mg/g, respectively), while higher hesperidin yields were achieved from the particle sizes of 2.00 and 1.40 mm (6.44 and 6.27 mg/g, respectively). Extraction temperature significantly affected only the recovery of the flavanone glycoside (P<0.05). As the extraction temperature increased from 30 to 50 °C the recovery of hesperidin increased from 6.59 to 7.84 mg/g, respectively. Neither extraction time nor ultrasonic power significantly affected the recovery of any individual phenolic compound

Optimization of extraction parameters of total phenolic compound from Cosmos caudatus

The wide ranges of extraction parameters used being identified from previous studies derives the need to find the best conditions to yield optimum extraction of total phenolic compounds from Cosmos caudatus. The objective of this research is to determine the optimum extraction parameters, namely ultrasonic frequency (from 30 to 70 kHz), sample-to-solvent ratio (from 2 to 10 w/v %) and extraction time (from 30 to 300 minutes) of total phenolic compound from Cosmos caudatus. The experimental design was first generated from Response Surface Methodology by using Design Expert 7.1.6 with three independent variables, namely ultrasonic frequency, sample-to-solvent ratio (SSR) and extraction time. Results showed that the optimization of extracting total phenolic compounds (TPC) from Cosmos caudatus can be accomplished by employing ultrasonic frequency of 70 kHz, 2g dry sample/100mL ethanol and extraction time of 300 minutes with yield of 7.7395 mg GAE/g dw which is in close agreement with the predicted value (7.5359 mg GAE/g dw). Analysis of variance showed significant ultrasonic frequency and sample-to-solvent ratio, but insignificant extraction time. This might be partly due to phenolic oxidation during the extraction itself. Since previous and present studies suggests that the extraction of total phenolic compounds can be further optimized, upcoming studies need to be directed at varying the significant extraction parameters including the extraction temperature, types of solvent used and extraction methods