Green ultrasound-assisted extraction of carotenoids based on the bio-refinery concept using sunflower oil as an alternative solvent

A green, inexpensive and easy-to-use method for carotenoids extraction from fresh carrots assisted by ultrasound was designed in this work. Sunflower oil was applied as a substitute to organic solvents in this green ultrasound-assisted extraction (UAE): a process which is in line with green extraction and bio-refinery concepts. The processing procedure of this original UAE was first compared with conventional solvent extraction (CSE) using hexane as solvent. Moreover, the UAE optimal conditions for the subsequent comparison were optimized using response surface methodology (RSM) and ultra performance liquid chromatography – diode array detector – mass spectroscopy (UPLC–DAD–MS). The results showed that the UAE using sunflower as solvent has obtained its highest β-carotene yield (334.75 mg/l) in 20 min only, while CSE using hexane as solvent obtained a similar yield (321.35 mg/l) in 60 min. The green UAE performed under optimal extraction conditions (carrot to oil ratio of 2:10, ultrasonic intensity of 22.5 W cm^?2, temperature of 40 °C and sonication time of 20 min) gave the best yield of β-carotene.     

Intensification of extraction of curcumin from Curcuma amada using ultrasound assisted approach: Effect of different operating parameters

Curcumin, a dietary phytochemical, has been extracted from rhizomes of Curcuma amada using ultrasound assisted extraction (UAE) and the results compared with the conventional extraction approach to establish the process intensification benefits. The effect of operating parameters such as type of solvent, extraction time, extraction temperature, solid to solvent ratio, particle size and ultrasonic power on the extraction yield have been investigated in details for the approach UAE. The maximum extraction yield as 72% was obtained in 1 h under optimized conditions of 35 °C temperature, solid to solvent ratio of 1:25, particle size of 0.09 mm, ultrasonic power of 250 W and ultrasound frequency of 22 kHz with ethanol as the solvent. The obtained yield was significantly higher as compared to the batch extraction where only about 62% yield was achieved in 8 h of treatment. Peleg’s model was used to describe the kinetics of UAE and the model showed a good agreement with the experimental results. Overall, ultrasound has been established to be a green process for extraction of curcumin with benefits of reduction in time as compared to batch extraction and the operating temperature as compared to Soxhlet extraction.     

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 61 μm and an extraction time of 17 min which resulted the recovery of 1102 μg 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 55.3 μg/g DPP for α-solanine, α-chaconine, solanidine and demissidine respectively. Whereas for SLE yields were 180.3, 337.6, 160.2 and 32.4 μg/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.     

Ultrasonic assisted dispersive solid-phase microextraction of Eriochrome Cyanine R from water sample on ultrasonically synthesized lead (II) dioxide nanoparticles loaded on activated carbon: Experimental design methodology

The present research focus on designing an appropriate dispersive solid-phase microextraction (UA-DSPME) for preconcentration and determination of Eriochrome Cyanine R (ECR) in aqueous solutions with aid of sonication using lead (II) dioxide nanoparticles loaded on activated carbon (PbO-NPs-AC). This material was fully identified with XRD and SEM. Influence of pH, amounts of sorbent, type and volume of eluent, and sonication time on response properties were investigated and optimized by central composite design (CCD) combined with surface response methodology using STATISTICA. Among different solvents, dimethyl sulfoxide (DMSO) was selected as an efficient eluent, which its combination by present nanoparticles and application of ultrasound waves led to enhancement in mass transfer. The predicted maximum extraction (100%) under the optimum conditions of the process variables viz. pH 4.5, eluent 200 μL, adsorbent dosage 2.5 mg and 5 min sonication was close to the experimental value (99.50%). at optimum conditions some experimental features like wide 5–2000 ng mL⁻¹ ECR, low detection limit (0.43 ng mL⁻¹, S/N = 3:1) and good repeatability and reproducibility (relative standard deviation, <5.5%, n = 12) indicate versatility in successful applicability of present method for real sample analysis. Investigation of accuracy by spiking known concentration of ECR over 200–600 ng mL⁻¹ gave mean recoveries from 94.850% to 101.42% under optimal conditions. The procedure was also applied for the pre-concentration and subsequent determination of ECR in tap and waste waters.     

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 40 min and a solvent-to-material ratio of 19.21 mL/g for total phenols, and an ethanol concentration of 80%, an extraction time of 33.54 min and solvent-to-material ratio of 22.72 mL/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.     

Novel synthesis of nanocomposite for the extraction of Sildenafil Citrate (Viagra) from water and urine samples: Process screening and optimization

A sensitive analytical method is investigated to concentrate and determine trace level of Sildenafil Citrate (SLC) present in water and urine samples. The method is based on a sample treatment using dispersive solid-phase micro-extraction (DSPME) with laboratory-made Mn@ CuS/ZnS nanocomposite loaded on activated carbon (Mn@ CuS/ZnS-NCs-AC) as a sorbent for the target analyte. The efficiency was enhanced by ultrasound-assisted (UA) with dispersive nanocomposite solid-phase micro-extraction (UA-DNSPME). Four significant variables affecting SLC recovery like; pH, eluent volume, sonication time and adsorbent mass were selected by the Plackett-Burman design (PBD) experiments. These selected factors were optimized by the central composite design (CCD) to maximize extraction of SLC. The results exhibited that the optimum conditions for maximizing extraction of SLC were 6.0 pH, 300 μL eluent (acetonitrile) volume, 10 mg of adsorbent and 6 min sonication time. Under optimized conditions, virtuous linearity of SLC was ranged from 30 to 4000 ng mL⁻¹ with R² of 0.99. The limit of detection (LOD) was 2.50 ng mL⁻¹ and the recoveries at two spiked levels were ranged from 97.37 to 103.21% with the relative standard deviation (RSD) less than 4.50% (n = 15). The enhancement factor (EF) was 81.91. The results show that the combination UAE with DNSPME is a suitable method for the determination of SLC in water and urine samples.     

Bio-refinery of orange peels waste: A new concept based on integrated green and solvent free extraction processes using ultrasound and microwave techniques to obtain essential oil,polyphenols and pectin

In this study, extraction of essential oil, polyphenols and pectin from orange peel has been optimized using microwave and ultrasound technology without adding any solvent but only “in situ” water which was recycled and used as solvent. The essential oil extraction performed by Microwave Hydrodiffusion and Gravity (MHG) was optimized and compared to steam distillation extraction (SD). No significant changes in yield were noticed: 4.22 ± 0.03% and 4.16 ± 0.05% for MHG and SD, respectively. After extraction of essential oil, residual water of plant obtained after MHG extraction was used as solvent for polyphenols and pectin extraction from MHG residues. Polyphenols extraction was performed by ultrasound-assisted extraction (UAE) and conventional extraction (CE). Response surface methodology (RSM) using central composite designs (CCD) approach was launched to investigate the influence of process variables on the ultrasound-assisted extraction (UAE). The statistical analysis revealed that the optimized conditions of ultrasound power and temperature were 0.956 W/cm² and 59.83 °C giving a polyphenol yield of 50.02 mg GA/100 g dm. Compared with the conventional extraction (CE), the UAE gave an increase of 30% in TPC yield. Pectin was extracted by conventional and microwave assisted extraction. This technique gives a maximal yield of 24.2% for microwave power of 500 W in only 3 min whereas conventional extraction gives 18.32% in 120 min. Combination of microwave, ultrasound and the recycled “in situ” water of citrus peels allow us to obtain high added values compounds in shorter time and managed to make a closed loop using only natural resources provided by the plant which makes the whole process intensified in term of time and energy saving, cleanliness and reduced waste water.     

Effect of ultrasound on the extraction of total anthocyanins from Purple Majesty potato

This study examined anthocyanin extraction using the application of ultrasound to raw freeze dried, microwaved and raw sliced Purple Majesty potato, a new pigmented potato variety rich in anthocyanins. A 20 kHz probe was used for the sonication at 3 different amplitudes (30%, 50% and 70%) and ethanol in water at different ratios (50:50 and 70:30 v/v) was used for the extraction. Anthocyanin extraction from raw freeze dried purple potato was optimal at an ethanol:water ratio (70:30; v/v) after 5 min of ultrasonication, while the least amount of anthocyanins was extracted from raw sliced potatoes. The application of microwaves (as a pre-treatment) before the UAE resulted in an increase in the amount of anthocyanins extracted and a decrease in the amount of solvent used. Analysis of variance showed that potato form, ultrasonication time, ultrasonication amplitude and solvent ratio as well as two and three way interactions between some of these factors had a very significant effect (p < 0.000) on the amount of anthocyanins extracted.     

Development and validation of an efficient ultrasound assisted extraction of phenolic compounds from flax (Linum usitatissimum L.) seeds

Flaxseed accumulates in its seedcoat a macromolecular complex composed of lignan (secoisolariciresinol diglucoside, SDG), flavonol (herbacetin diglucoside, HDG) and hydroxycinnamic acids (p-couramic, caffeic and ferulic acid glucosides). Their antioxidant and/or cancer chemopreventive properties support their interest in human health and therefore, the demand for their extraction. In the present study, ultrasound-assisted extraction (UAE) of flaxseed phenolic compounds was investigated. Scanning Electron Microscopy imaging and histochemical analysis revealed the deep alteration of the seedcoat ultrastructure and the release of the mucilage following ultrasound treatment. Therefore, this method was found to be very efficient for the reduction of mucilage entrapment of flaxseed phenolics. The optimal conditions for UAE phenolic compounds extraction from flaxseeds were found to be: water as solvent supplemented with 0.2 N of sodium hydroxide for alkaline hydrolysis of the SDG–HMG complex, an extraction time of 60 min at a temperature of 25 °C and an ultrasound frequency of 30 kHz. Under these optimized and validated conditions, highest yields of SDG, HDG and hydroxycinnamic acid glucosides were detected in comparison to other published methods. Therefore, the procedure presented herein is a valuable method for efficient extraction and quantification of the main flaxseed phenolics. Moreover, this UAE is of particular interest within the context of green chemistry in terms of reducing energy consumption and valuation of flaxseed cakes as by-products resulting from the production of flax oil.     

Effects of processing parameters in the sonic assisted water extraction (SAWE) of 6-gingerol

The use of water in subcritical conditions for extraction has several drawbacks. These include the safety features, higher production costs and possible degradation of the bioactive compounds. To overcome these problems, sonic energy and an entrainer were used as external interventions to decrease the polarity of water at milder operating conditions. The effect of low (28 kHz) and high (800 kHz) frequencies of sonication in the extraction of the main ginger bioactive compound (6-gingerol) were compared. Six parameters were studied: mean particle size (MPS, mm), time of extraction, applied power, sample to solvent ratio (w/v), temperature of extraction, and the percentage of entrainer. The optimum conditions for high frequency SAWE prototype were MPS 0.89–1.77 mm, 45 min, 40 W applied power, 1:30 (w/v), 45 °C, and 15% of ethanol as entrainer. Two-way analysis of variance (ANOVA) gave the most significant parameter, which was power with F (1, 45.07), p < 2.50 × 10⁻⁹. Although the effect of low frequency was stronger than high frequency, at the optimum conditions of the sample to solvent ratio 1:30 (w/v) with 700 mL solvent and temperature 45 °C, the concentration and recovery of 6-gingerol from high frequency of SAWE prototype was 2.69 times higher than at low frequency of SAWE. It was found that although the effects of high frequency (800 kHz) were negligible in other studies, it could extract suitable compounds, such as 6-gingerol, at lower temperature. Therefore, the effects of sonication, which cause an enlargement in the cell wall of the ginger plant matrix, were observed using a Scanning Electron Microscope (SEM). It was found that the applied power of sonication was the most significant parameter compared to the other parameters.     

Ultrasound-assisted rapid extraction and kinetic modelling of influential factors: Extraction of camptothecin from Nothapodytes nimmoniana plant

Ultrasound-assisted extraction (UAE) of commercially important natural product camptothecin (CPT) from Nothapodytes nimmoniana plant has been investigated. The influences of process factors such as electric acoustic intensity, solid to liquid ratio, duty cycle, temperature and particle size on the maximum extraction yield and kinetic mechanisms of the entire extraction process have been investigated. The kinetics results showed that increasing the intensity, duty cycle, solid to liquid ratio and decreasing the particle size lead to substantial increase in extraction yields compared to classical stirring extraction. Different kinetic models were applied to fit the experimental data. The second order rate model appears to be the best. The extraction rate constant, initial extraction rate and the equilibrium concentration for all experimental conditions have been calculated. SEM analysis of spent plant material clearly showed hollow openings on cell structure, which could be directly correlated to explosive disruption by the action of ultrasound waves. Overall 1.7-fold increase in extraction yields of CPT (0.32% w/w) and decrease in time from 6 h to 18 min was observed over the stirring method.     

Ultrasound assisted extraction of pectin from waste Artocarpus heterophyllus fruit peel

Four factors three level face centered central composite response surface design was employed in this study to investigate and optimize the effect of process variables (liquid-solid (LS) ratio (10:1–20:1 ml/g), pH (1−2), sonication time (15–30 min) and extraction temperature (50–70 °C)) on the maximum extraction yield of pectin from waste Artocarpus heterophyllus (Jackfruit) peel by ultrasound assisted extraction method. Numerical optimization method was adapted in this study and the following optimal condition was obtained as follows: Liquid-solid ratio of 15:1 ml/g, pH of 1.6, sonication time of 24 min and temperature of 60 °C. The optimal condition was validated through experiments and the observed value was interrelated with predicted value.     

Optimization of ultrasonic-assisted extraction (UAE) of betulin from white birch bark using response surface methodology

Betulin is an abundant naturally occurring triterpene, which makes it a potentially important raw material for a precursor of biologically active compounds. The objective of the current study was to determine the optimum UAE conditions for betulin from B. papyfera bark. The optimum conditions were evaluated with fractional factorial design and optimized using response surface methodology. High yields of betulin were observed from white birch bark by UAE technology. The solvent concentration and the ratio of material to solvent were the most significant parameters on betulin extraction as evaluated through FFD. The extraction conditions were further investigated with central composite design. The fitted second-order model revealed that the optimal conditions consisted of 98% ethonal concentration, 1:42 the ratio of white birch bark to solvent, extraction temperature 50 °C, ultrasonic frequency 5 kHz and extraction time 3 h. Under the optimized condition, the maximum productivity of betulin predicted is 23.17%. The extraction productivity and purity of betulin under the optimized extraction conditions were great higher than that of the non-optimized condition. The present study demonstrates that ultrasound is a great efficiency tool for the fast extraction of betulin from white birch bark.     

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, 120 kHz), ultrasonic power density (50, 100, 150 W/L) and extraction time (5, 15, 25 min) 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 40 kHz, a power density of 150 W/L and 25 min of extraction time. Under these conditions, the aqueous UAE would achieve a maximum of 32.31 mg GA/100 g fw for total phenolics and 2.04 mg quercetin/100 g fw for total flavonols. Regarding the antioxidant capacity, the maximum predicted values were 53.47 and 43.66 mg Trolox/100 g 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.     

Aqueous ionic liquid based ultrasonic assisted extraction of four acetophenones from the Chinese medicinal plant Cynanchum bungei Decne

In this study, an aqueous ionic liquid based ultrasonic assisted extraction (ILUAE) method for the extraction of the four acetophenones, namely 4-hydroxyacetophenone (1), 2,5-dihydroxyacetophenone (2), baishouwubenzophenone (3) and 2,4-dihydroxyacetophenone (4) from the Chinese medicinal plant Cynanchum bungei was developed. Three kinds of aqueous l-alkyl-3-methylimidazolium ionic liquids with different anion and alkyl chain were investigated. The results indicated that ionic liquids (ILs) showed remarkable effects on the extraction efficiency of acetophenones. In addition, the ILUAE, including several ultrasonic parameters, such as the ILs concentration, solvent to solid ratio, power, particle size, temperature, and extraction time have been optimized. Under these optimal conditions (e.g., with 0.6 M [C₄MIM]BF₄, solvent to solid ratio of 35:1, power of 175 W, particle size of 60–80 mesh, temperature of 25 °C and time of 50 min), this approach gained the highest extraction yields of four acetophenones 286.15, 21.65, 632.58 and 205.38 μg/g, respectively. The proposed approach has been evaluated by comparison with the conventional heat-reflux extraction (HRE) and regular UAE. The results indicated that ILUAE is an alternative method for extracting acetophenones from C. bungei.     

Ultrasonically enhanced fractionation of milk fat in a litre-scale prototype vessel

The ultrasonic fractionation of milk fat in whole milk to fractions with distinct particle size distributions was demonstrated using a stage-based ultrasound-enhanced gravity separation protocol. Firstly, a single stage ultrasound gravity separation was characterised after various sonication durations (5–20 min) with a mass balance, where defined volume partitions were removed across the height of the separation vessel to determine the fat content and size distribution of fat droplets. Subsequent trials using ultrasound-enhanced gravity separation were carried out in three consecutive stages. Each stage consisted of 5 min sonication, with single and dual transducer configurations at 1 MHz and 2 MHz, followed by aliquot collection for particle size characterisation of the formed layers located at the bottom and top of the vessel. After each sonication stage, gentle removal of the separated fat layer located at the top was performed.Results indicated that ultrasound promoted the formation of a gradient of vertically increasing fat concentration and particle size across the height of the separation vessel, which became more pronounced with extended sonication time. Ultrasound-enhanced fractionation provided fat enriched fractions located at the top of the vessel of up to 13 ± 1% (w/v) with larger globules present in the particle size distributions. In contrast, semi-skim milk fractions located at the bottom of the vessel as low as 1.2 ± 0.01% (w/v) could be produced, containing proportionally smaller sized fat globules. Particle size differentiation was enhanced at higher ultrasound energy input (up to 347 W/L). In particular, dual transducer after three-stage operation at maximum energy input provided highest mean particle size differentiation with up to 0.9 μm reduction in the semi-skim fractions. Higher frequency ultrasound at 2 MHz was more effective in manipulating smaller sized fat globules retained in the later stages of skimming than 1 MHz. While 2 MHz ultrasound removed 59 ± 2% of the fat contained in the initial sample, only 47 ± 2% was removed with 1 MHz after 3 ultrasound-assisted fractionation stages.     

Kinetic improvement of olive leaves’ bioactive compounds extraction by using power ultrasound in a wide temperature range

In this study, the effect of temperature and ultrasonic application on extraction kinetics of polyphenols from dried olive leaf was investigated. Conventional (CVE) and ultrasonic-assisted extraction (UAE) were performed at 10, 20, 30, 50 and 70 °C using water as solvent. Extracts were characterized by measuring the total phenolic content, the antioxidant capacity and the oleuropein content (HPLC–DAD/MS–MS). Moreover, Naik’s model was used to mathematically describe the extraction kinetics. The experimental results showed that phenolic extraction was faster in UAE (ultrasonic-assisted extraction) than in CVE (conventional extraction), being extraction kinetics satisfactorily described using Naik model (include VAR > 98%). Besides, the total phenolic content, the antioxidant capacity and the oleuropein content were significantly (p < 0.05) improved by increasing the temperature in both CVE and UAE. Oleuropein content reached 6.57 ± 0.18 being extracted approximately 88% in the first minute for UAE experiments.     

Optimization of ultrasonic-assisted extraction of pomegranate (Punica granatum L.) seed oil

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 140 W, 40 °C, 36 min, and 10 ml/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.     

Comparisons between conventional,ultrasound-assisted and microwave-assisted methods for extraction of anthraquinones from Heterophyllaea pustulata Hook f. (Rubiaceae)

This work reports a comparative study about extraction methods used to obtain anthraquinones (AQs) from stems and leaves of Heterophyllae pustulata Hook (Rubiáceae). One of the conventional procedures used to extract these metabolites from a vegetable matrix is by successive Soxhlet extractions with solvents of increasing polarity: starting with hexane to eliminate chlorophylls and fatty components, following by benzene and finally ethyl acetate. However, this technique shows a low extraction yield of total AQs, and consumes large quantities of solvent and time. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been investigated as alternative methods to extract these compounds, using the same sequence of solvents. It was found that UAE increases the extraction yield of total AQs and reduces the time and amount of solvent used. Nevertheless, the combination UAE with benzene, plus MAE with ethyl acetate at a constant power of 900 W showed the best results. A higher yield of total AQs was obtained in less time and using the same amount of solvent that UAE. The optimal conditions for this latter procedure were UAE with benzene at 50 °C during 60 min, followed by MAE at 900 W during 15 min using ethyl acetate as extraction solvent.     

High intensity ultrasound treatment of protein isolate extracted from dephenolized sunflower meal: Effect on physicochemical and functional properties

The influence of high intensity ultrasound (HIUS) on physicochemical and functional properties of sunflower protein isolates was investigated. Protein solutions (10% w/v) were treated with ultrasound probe (20 kHz) and ultrasound bath (40 kHz) for 5, 10, 20 and 30 min. Thermal stability of protein isolates was reduced as indicated by differential scanning calorimetry. Minimum thermal stability was observed at 20 min of sonication and increased further with increase in treatment time indicating aggregation at prolonged sonication. SDS-PAGE profile of proteins showed a significant reduction in molecular weight. Further, surface hydrophobicity and sulfhydryl content increased after HIUS treatment indicating partial unfolding of proteins and reduction in the intermolecular interactions. The particle size analysis showed that HIUS treatment reduced the particle size. Less turbid solution were observed largely due to reduction in particle size. HIUS decreased the available lysine content in protein isolates. Solubility, emulsifying capacity, emulsion stability, foaming capacity, foam stability and oil binding capacity were improved significantly, while as, water binding capacity was decreased. The effect of HIUS on physicochemical and functional properties of sunflower protein isolates was more pronounced in probe sonication rather than bath sonication. Protein isolates with improved functional properties can be obtained using high intensity ultrasound technology.