Optimal Ultrasound-assisted Extraction Conditions Research Articles

Optimization of Ultrasound-Assisted Extraction Procedure to Determine Antioxidant Capacity of Rapeseed Cultivars

Ultrasound-assisted extraction (UAE) was applied to extract total antioxidants from two rapeseed varieties. The antioxidant capacity of spring and winter rapeseed cultivars was determined by two different analytical methods: 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH). Effects of three independent variables, sonication time (t), volume of methanol-to-rapeseed weight ratio (V/m), and concentration of methanol (c) on the antioxidant capacity of rapeseed varieties, were studied by response surface methodology (RSM). Box–Behnken design (BBD) was used to obtain the optimal conditions of the UAE. The optimal UAE conditions were evaluated with an extraction time of 13.8 min, a solvent-to-material ratio of 26.2 mL/g and a solvent concentration of 50.3 % for antioxidant capacity of spring rapeseed cultivar (ABTS = 62.7 mmol Trolox equivalent (TE)/100 g, DPPH = 38.3 mmol TE/100 g), whereas the predicted optimum t = 13.3 min, V/m = 29.5 mL/g, and c = 38.3 % resulted in ABTS = 62.0 mmol TE/100 g, DPPH = 48.6 mmol TE/100 g for a winter rapeseed cultivar. Results of ABTS and DPPH determinations correlate with the predicted values (R 2 = 0.9435 and 0.9796 for the spring rapeseed variety and 0.9952, 0.9252 for the winter rapeseed variety).

Ultrasonic extraction of steroidal alkaloids from potato peel waste

Potato processors produce large volumes of waste in the form of potato peel which is either discarded or sold at a low price. Potato peel waste is a potential source of steroidal alkaloids which are biologically active secondary metabolites which could serve as precursors to agents with apoptotic, chemopreventive and anti-inflammatory properties. The present study investigated the relative efficacy of ultrasound assisted extraction (UAE) and solid liquid extraction (SLE) both using methanol, to extract steroidal alkaloids from potato peel waste and identified optimal conditions for UAE of α-solanine, α-chaconine, solanidine and demissidine. Using response surface methodology optimal UAE conditions were identified as an amplitude of 61μm and an extraction time of 17min which resulted the recovery of 1102μg steroidal alkaloids/g dried potato peel (DPP). In contrast, SLE yielded 710.51 glycoalkaloid μg/g DPP. Recoveries of individual glycoalkoids using UAE yielded 273, 542.7, 231 and 55.3μg/g DPP for α-solanine, α-chaconine, solanidine and demissidine respectively. Whereas for SLE yields were 180.3, 337.6, 160.2 and 32.4μg/g DPP for α-solanine, α-chaconine, solanidine and demissidine respectively. The predicted values from the developed second order quadratic polynomial equation were in close agreement with the experimental values with low average mean deviation (E<5%) values. Predicted models were highly significant (p<0.05) for all parameters studied. This study indicates that UAE has strong potential as an extraction method for steroidal alkaloids from potato peel waste.

Effect of acoustic frequency and power density on the aqueous ultrasonic-assisted extraction of grape pomace (Vitis vinifera L.) – A response surface approach

Aqueous ultrasound-assisted extraction (UAE) of grape pomace was investigated by Response Surface Methodology (RSM) to evaluate the effect of acoustic frequency (40, 80, 120kHz), ultrasonic power density (50, 100, 150W/L) and extraction time (5, 15, 25min) on total phenolics, total flavonols and antioxidant capacity. All the process variables showed a significant effect on the aqueous UAE of grape pomace (p<0.05). The Box–Behnken Design (BBD) generated satisfactory mathematical models which accurately explain the behavior of the system; allowing to predict both the extraction yield of phenolic and flavonol compounds, and also the antioxidant capacity of the grape pomace extracts. The optimal UAE conditions for all response factors were a frequency of 40kHz, a power density of 150W/L and 25min of extraction time. Under these conditions, the aqueous UAE would achieve a maximum of 32.31mg GA/100g fw for total phenolics and 2.04mg quercetin/100g fw for total flavonols. Regarding the antioxidant capacity, the maximum predicted values were 53.47 and 43.66mg Trolox/100g fw for CUPRAC and FRAP assays, respectively. When comparing with organic UAE, in the present research, from 12% to 38% of total phenolic bibliographic values were obtained, but using only water as the extraction solvent, and applying lower temperatures and shorter extraction times. To the best of the authors’ knowledge, no studies specifically addressing the optimization of both acoustic frequency and power density during aqueous-UAE of plant materials have been previously published.

Optimisation of ultrasound-assisted extraction of natural pigment from annatto seeds by response surface methodology (RSM)

The present study reports on the extraction of natural pigment from annatto seeds. Response surface methodology (RSM) was used to investigate the effect of process variables on the ultrasound-assisted extraction (UAE). Four independent variables including temperature (20–80°C), sonication time (2–10min), duty cycle (0.2–0.8s) and the ratio of seeds to the solvent (5–20%) were studied. According to the results, the optimal UAE condition was obtained with a temperature of 72.7°C, extraction time of 7.25min, the ratio of seed to solvent of 14% and duty cycle of 0.8s. At these conditions, extraction yield determined as 6.35% and the absorbance value as 0.865%. The experimental values under optimal condition were in good consistent with the predicted values, which suggested UAE is more efficient process as compared to conventional extraction.

Optimization of ultrasound-assisted extraction of phenolic compounds from Cimicifugae rhizoma with response surface methodology.

Background:Cimicifugae rhizoma was a Ranunculaceae herb belonging to the composite family, and the roots of C. rhizoma have been widely used in tradition Chinese medicine.Materials and Methods:Ultrasound-assisted extraction (UAE) of phenolic compounds from C. rhizoma. Caffeic acid (CA), isoferulic acid (IA), ferulic acid (FA), and total phenols were quantified by high-performance liquid chromatography-diode array detection and ultraviolet-visible spectrophotometer. Effects of several experimental parameters, such as ultrasonic power (W), extraction temperature (°C), and ethanol concentration (%) on extraction efficiencies of phenolic compounds from C. rhizoma were evaluated.Results:The results showed that the optimal UAE condition was obtained with ultrasonic power of 377.35 W, extraction temperature of 70°C, and ethanol concentration of 58.37% for total phenols, and ultrasonic power of 318.28 W, extraction temperature of 59.65°C, and ethanol concentration of 64.43% for combination of CA, IA, FA.Conclusions:The experimental values under optimal conditions were in good consistent with the predicted values, which suggested UAE is more efficient for the extraction of phenolic compounds from plant materials.

Optimisation of ultrasound assisted extraction of phenolic compounds from Sparganii rhizoma with response surface methodology

The present study reports on the extraction of phenolic compounds from sparganii rhizome. Box–Behnken Design (BBD), a widely used form of response surface methodology (RSM), was used to investigate the effect of process variables on the ultrasound-assisted extraction (UAE). Three independent variables including ethanol concentration (%), extraction time (min) and solvent-to-material ratio (mL/g) were studied. The results showed that the optimal UAE condition was obtained with an ethanol concentration of 75.3%, an extraction time of 40min and a solvent-to-material ratio of 19.21mL/g for total phenols, and an ethanol concentration of 80%, an extraction time of 33.54min and solvent-to-material ratio of 22.72mL/g for combination of ρ-hydroxybenzaldehyde, ρ-coumaric acid, vanillic acid, ferulic acid, rutin and kaempferol. The experimental values under optimal conditions were in good consistent with the predicted values, which suggested UAE is more efficient process as compared to solvent extraction.

Aqueous two-phase system coupled with ultrasound for the extraction of lignans from seeds of Schisandra chinensis (turcz.) Baill

In this study the potential use of an aqueous two phase system (ATPS) coupled with ultrasound for the extraction of lignans from Schisandra chinensis seeds was evaluated and optimized using response surface methodology (RSM). The main bioactive components, schizandrin (SA), schisantherin A (SAA) and deoxyschizandrin (DSA) were selected as markers. The partitioning behavior of lignans in different salt-types of ATPS was compared. The optimization ATPS of 25% (w/w) (NH4)2SO4 and 19% (w/w) ethanol were selected based on their higher upper phase partitioning coefficient (>74) and the recovery (>93%) for three markers. Using the optimized ATPS solvent, the RMS results showed 20:1 of solvent:solid, 800W and 61.1min were the optimal ultrasound assisted extraction conditions, under which 13.10mg/g SA, 1.87mg/g SAA and 1.84mg/g DSA were recovered in the upper phase, whereas the wasted stigmas accumulated in the lower phase. Compared with 80% ethanol (v/v) ultrasonic extraction, similar yields were obtained, but the present method exhibited higher extraction purity for the selective extraction of lignans from S. chinensis seeds.

Ultrasound-assisted extraction of five isoflavones from Iris tectorum Maxim

This study investigated the use of ultrasound-assisted extraction (UAE) to improve the extraction efficiency of the classical solvent extraction techniques such as maceration extraction (ME) and soxhlet extraction (SE) to extract five isoflavones (tectoridin, iristectorin B, iristectorin A, tectorigenin and iristectorigenin A) from Iris tectorum. The effects of various factors such as extraction solvent, solvent concentration, temperature, solvent to solid ratio, ultrasound power, extraction time and particle size on the yield of target components were investigated. The optimal UAE conditions found were: 70% (v/v) methanol solution, temperature 45 °C, solvent to solid ratio 15 ml/g, ultrasound power 150 W, extraction time 45 min and particle size 60–80 mesh. The results indicated that compared with ME at 18 h and SE at 6 h, UAE gave the highest extraction yields of tectoridin, iristectorin B, iristectorin A, tectorigenin, iristectorigenin A and total isoflavones at 45 min. The results indicated that UAE was an alternative method for extracting isoflavones from I. tectorum.

Extraction and Identification of Flavonoids in Rape Bee Pollen

Rape bee pollen was used as the raw material to identify its characteristic component-flavonoids. The optimal ultrasound-assisted extraction processing conditions for flavonoids from rape bee pollen were explored by quadratic regression orthogonal rotation experiments, response surface analysis and ridge analysis. The extracted sample with acid hydrolysis was analyzed using HPLC-DAD and HPLC/MS. Results showed that the optimal ultrasound-assisted extraction conditions were ethanol concentration of 76%, material-liquid ratio of 1:30, ultrasonic treatment time of 33 min, ultrasonic treatment temperature of 51 ℃. Under the optimal conditions, the yield of flavonoids was 1.89%, which was close to theoretical yield of 2.12%. HPLCDAD and HPLC/MS analyses exhibited that nine kinds of flavonoid aglycones were identified in rape bee pollen. The identified flavonoids included quercetin, kaempferol, isorhamnetin and naringenin. These investigations provide a research method and theoretical reference for the identification of plant sources and authenticity of bee pollen.