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In this study, the effect of ultrasound-assisted non-covalent binding of different polyphenols (tannins, quercetin, and resveratrol) on the structure and functional properties of myofibrillar proteins (MP) from the golden threadfin (Nemipterus virgatus) was investigated. The effect of ultrasound-assisted polyphenol incorporation on the structure and properties of MP was evaluated by multispectral analysis, interfacial properties, emulsification properties and antioxidant properties et al. The results revealed that the protein–polyphenol interaction led to a conformational change in the microenvironment around the hydrophobic amino acid residues, resulting in an increase in the equilibrium of the MP molecules in terms of affinity and hydrophobicity. Ultrasound assisted polyphenols addition also led to a significant decrease of the oil/water interfacial tension (from 21.22 mN/m of MP to 8.66 mN/m of UMP-TA sample) and a significant increase of the EAI (from 21.57 m2/g of MP to 28.79 m2/g of UMP-TA sample) and ES (from 84.76 min of MP to 124.25 min of UMP-TA). In addition, ultrasound-assisted polyphenol incorporation could enhance the antioxidant properties of MP, with the DPPH and ABTS radical scavenging rate of UMP-TA increase of 47.7 % and 55.2 % in comparison with MP, respectively. The results demonstrated that the noncovalent combination with polyphenols under ultrasound-assisted conditions endowed MP with better functional properties, including solubility, emulsification, foaming, and antioxidant properties through structure change. This study can provide innovative theoretical guidance for effectively preparing aquatic protein–polyphenol non-covalent complexes with multiple functions and improving the processing and utilization value of aquatic proteins.

ABSTRACTAchieving grain refinement in the wire-arc directed energy deposition (DED) process of NiTi alloy is highly challenging. We have successfully obtained NiTi alloy with a fine microstructure and observed an improvement in superelastic recoverability by introducing an ultrasound-assisted field during the deposition process. The results show that the average grain size of the NiTi alloy samples decreased from 147.3 to 72.2 μm. Additionally, the recoverable strain of the samples increased significantly from 3.7% to 4.4%. This is attributed to the ultrasonic cavitation and acoustic streaming phenomena during the ultrasound-assisted process, which promotes the columnar-to-equiaxed transition (CET) during the solidification process. Fundamentally, the key to the enhancement of recoverable strain after ultrasound-assisted is that the formation of equiaxial grains provides more strain compatibility to the grain boundaries, which reduces the formation of dislocations during deformation.

Research and development of high-performance catalysts is a key technology to realize hydrogen energy storage and transportation based on liquid organic hydrogen carriers. Co/beta was prepared using beta zeolite as a carrier via an electrostatic adsorption (ESA)-chemical reduction method, and it was used as the template and reducing agent to prepare bimetallic catalysts via an ultrasonic assisted galvanic replacement process (UGR). The fabricated PdCo/beta were characterized by TEM, XPS, FT-IR, XRD, H2-TPR, and H2-TPD. It was shown that the ultrafine PdCo nanoparticles (NPs) are evenly distributed on the surface of the beta zeolite. There is electron transfer between metal NPs and strong-metal-support-interaction (SMSI), which results in highly efficient catalytic dodecahydro-N-ethylcarbazole (12H-NEC) dehydrogenation performance of PdCo bimetallic catalysts. The dehydrogenation efficiency reached 100 % in 4 h at 180 °C and 95.3 % in 6 h at 160 °C. The TOF of 146.22 min−1 is 7 times that of Pd/beta. The apparent activation energy of the reaction is 66.6 kJ/mol, which is much lower than that of Pd/beta. Under the action of ultrasonic waves, the galvanic replacement reaction is accelerated, and the intermetal and metal-carrier interactions are enhanced, which improves the catalytic reaction performance.

In this study, eleven kinds of flavonoids were identified from F. tataricum bran (FTB) by UPLC-Q-TOF-MS, and HPLC-DAD analysis revealed that four compounds, including rutin, quercetin, kaempferol, and nicotiflorin, were the most significant components. Subsequently, natural deep eutectic solvent-based ultrasound-assisted extraction (NADES-UAE) was employed to extract flavonoids from FTB. Among the six kinds of NADES prepared, choline chloride–ethylene glycol (ChCl-EG) was identified as a promising candidate for extracting flavonoids due to its superior extraction performance. The extraction conditions were statistically investigated using response surface methodology conducted by Box-Behnken design (BBD). The optimal operational conditions were as follows: ultrasonic time 268 s, ultrasonic temperature 76 °C, and liquid–solid ratio 43 mL/g, which resulted in a high total flavonoid yield of 40.29 mg/g. Afterwards, the efficient extraction mechanism of NADES-UAE was comprehensively explored through FT-IR spectra, COSMO model, and microstructural analysis. In conclusion, NADES-UAE extraction is considered a green, efficient, and sustainable method for FTB flavonoids.

Cellulose acetate is an important product derived from cellulose. Cellulose acetate can be used in a variety of applications including coatings, textile fibers, consumer goods, filtration membranes, composites, laminates, pharmaceutical, and medical items. Rice husk is a lignocellulosic material that contains cellulose and hemicellulose. The aims of this study were to determine the effect of process variables on the cellulose acetate product formation by ultrasound-assisted acetylation using iodine as a catalyst and to characterize the cellulose acetate product. The research was conducted through the delignification, bleaching, acetylation, and characterization processes. The results showed that the optimum yield of cellulose acetate was obtained at the temperature of 60 °C, the reaction time of 50 min, the weight of the catalyst of 10% of cellulose weight, and the ratio of cellulose and acetic anhydride of 1:5 (w/v). The acetylation process using iodine as a catalyst with an ultrasound-assisted method was more effective than the conventional acetylation (acetic acid glacial and sulfuric acid as a catalyst).

Cellulose acetate is an important product derived from cellulose. Cellulose acetate can be used in a variety of applications including coatings, textile fibers, consumer goods, filtration membranes, composites, laminates, pharmaceutical, and medical items. Rice husk is a lignocellulosic material that contains cellulose and hemicellulose. The aims of this study were to determine the effect of process variables on the cellulose acetate product formation by ultrasound-assisted acetylation using iodine as a catalyst and to characterize the cellulose acetate product. The research was conducted through the delignification, bleaching, acetylation, and characterization processes. The results showed that the optimum yield of cellulose acetate was obtained at the temperature of 60 °C, the reaction time of 50 min, the weight of the catalyst of 10% of cellulose weight, and the ratio of cellulose and acetic anhydride of 1:5 (w/v). The acetylation process using iodine as a catalyst with an ultrasound-assisted method was more effective than the conventional acetylation (acetic acid glacial and sulfuric acid as a catalyst).

The utilization of agricultural residues to obtain biocompounds of high-added value has significantly increased in the past decades. The conversion of agro-based residues into valuable products appears to be an economically efficient, environment-friendly, and protracted waste management practice. The implementation of ultrasonic technologies in the conversion of value-added goods from agricultural waste materials through pre-treatment and valorization processes has imparted many advantageous effects including rapid processing, effective process performance, minimization of processing steps, minimal dependency on harmful chemicals, and an increased yield and properties of bio-products. To further enliven the literature and inspire new research investigations, this review covers the comprehensive work including theoretical principles, processes, and potential benefits of ultrasonic treatment technologies to assist the production of bio-products which emphasize the extraction yield and the characteristic of the end-product extracted from agriculture residues. A detailed evaluation of these methods and key aspects impacting their performance as well as the features and shortcomings of each ultrasound-assisted approach is also discussed. This review also addressed some of the challenges associated with using ultrasonic irradiation and proposed several potential techniques to maximize productivity. Understanding the concept of ultrasonication technique allow the academician and industrial practitioners to explore the possibility of applying a greener and sustainable approach of biomass extraction to be translated into higher scale production of commercial products.

Objective: In order to improve the added value of eggplant peel, the best method of phenolic compounds from eggplant peel (EPP), as well as its hypoglycemic impact in vitro and in vivo were studied. Methods: EPP was extracted by ultrasonic-assisted method. The extraction parameters of EPP were optimized by single factor experiments and orthogonal experiment with yield as evaluation index. The inhibitory rate of EPP on α-glucosidase and its effects on body weight, fasting glucose, and glucose tolerance in mice were analyzed to evaluate its hypoglycemic efficacy in vitro and in vivo. Results: The optimal extraction conditions were as follows: Ultrasonic power 540 W, solid-liquid ratio 1:50 g/mL, extraction temperature 50 ℃ and extraction time 50 min. The extraction yield of EPP was 43.21%. The inhibitory rate on α-glucosidase increased with the increase of EPP concentration, and the inhibition rate of α-glucosidase was 45.46% with 1 mg/mL EPP. The body weight, fasting blood glucose and glucose tolerance of diabetic mice could be improved by EPP, and it had a significant hypoglycemic effect on diabetic mice. Conclusion: This study confirmed that EPP had hypoglycemic effect, which laid a theoretical foundation for comprehensive development and utilization of eggplant peel.

Cyperus esculentus tubers are rich in starch, oil, protein, dietary fiber, and other nutrients. Ultrasonic treatment can reduce the combination of starch, protein, and dietary fiber in C. esculentus tubers during extraction of C. esculentus starch, thereby improving the extraction yield and shortening of the extraction time. In this study, the extraction yield of C. esculentus starch was 92.2% using ultrasound-assisted alkali method. The microstructure analysis showed that the granule characteristics of C. esculentus starch and other starches were similar. X-ray diffraction analysis showed that C. esculentus starch possessed an A-type crystal structure. The onset temperature of gelatinization endotherm and peak temperature of gelatinization of C. esculentus starch were only lower than those of sweet potato starch, and higher than other starches, which is 67.9 °C. The content of resistance starch (RS) (11.0%) in C. esculentus starch was the highest among the six starches. As an underutilized resource, C. esculentus is a new crop with high quality, high yield, and high comprehensive utilization value. Its aerial parts can be used as feed, green manure, and its underground parts can be edible and oily. C. esculentus starch can be a valuable source to develop into new functional food.

Cyperus esculentus tubers are rich in starch, oil, protein, dietary fiber, and other nutrients. Ultrasonic treatment can reduce the combination of starch, protein, and dietary fiber in C. esculentus tubers during extraction of C. esculentus starch, thereby improving the extraction yield and shortening of the extraction time. In this study, the extraction yield of C. esculentus starch was 92.2% using ultrasound-assisted alkali method. The microstructure analysis showed that the granule characteristics of C. esculentus starch and other starches were similar. X-ray diffraction analysis showed that C. esculentus starch possessed an A-type crystal structure. The onset temperature of gelatinization endotherm and peak temperature of gelatinization of C. esculentus starch were only lower than those of sweet potato starch, and higher than other starches, which is 67.9 °C. The content of resistance starch (RS) (11.0%) in C. esculentus starch was the highest among the six starches. As an underutilized resource, C. esculentus is a new crop with high quality, high yield, and high comprehensive utilization value. Its aerial parts can be used as feed, green manure, and its underground parts can be edible and oily. C. esculentus starch can be a valuable source to develop into new functional food.

The study evaluated the effect of an ultrasound-assisted treatment on the structural and functional properties of sheep bone collagen (SBC). The type and distribution of SBC were analyzed by proteome (shotgun) technology combined with liquid chromatography-tandem mass spectrometry. Compared with pepsin extraction, the ultrasound-assisted treatment significantly increased the collagen extraction rate by 17.4 pp (P

Abstract Background Thoracic epidural placement (TEP) using the conventional anatomic landmark-based technique is technically challenging, may require multiple attempts, and is associated with a high failure rate (12–40%). We hypothesized that real-time ultrasound guidance would be superior in the “first-pass” success rate of TEP, when compared with the conventional technique. Methods This prospective, randomized, superiority trial was conducted in a University hospital, and recruited 96 patients undergoing elective major abdominal or thoracic surgery and scheduled to receive a TEP for postoperative analgesia. Patients were randomly allocated to receive TEP using either the conventional technique (Gp-Conv, n = 48) or real-time ultrasound guidance (Gp-Usg, n = 48). The success of TEP was defined as eliciting loss of resistance technique and being able to insert the epidural catheter. The primary outcome variable was the “first-pass success rate” meaning the successful TEP at the first needle insertion without redirection or readvancement of the Tuohy needle. The secondary outcomes included the number of skin punctures, number of attempts, the overall success rate, TEP time, and total procedure time. Results The first-pass success rate of TEP was significantly higher (p = 0.002) in Gp-Usg (33/48 (68.8%); 95%CI 55.6 to 81.9) than in Gp-Conv (17/48 (35.4%); 95%CI 21.9 to 49.0). There was no statistically significant difference (p = 0.12) in the overall success rate of TEP between the 2 study groups (Gp-Usg; 48/48 (100%) vs. Gp-Conv; 44/48 (91.7%); 95%CI 83.9 to 99.5). Ultrasound guidance reduced the median number of skin punctures (Gp-Usg; 1 [1, 1] vs Gp-Conv; 2 [1, 2.2], p

Lantana camara is known to have anti-bacterial properties which can be exploited to develop a natural food preservative. There is huge demand for natural preservatives in food industry due to the increased health risks associated with synthetic preservatives, development of effecient extraction methods are essential to retain heat sensitive bioactive compounds. This aim of this study was to compare the performance of microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and conventional solvent extraction (CSE) methods for extraction of freeze-dried lantana flower. The phytochemicals in freeze-dried flowers were characterized by GC-MS analysis and antibacterial properties were tested at different concentrations (50, 100, and 150 µl) against E.coli, Salmonella, and S. aureus. It was evident that the UAE offered the highest yield (64%), followed by MAE (53%) and CSE (49%) with distilled water as solvent. The freeze-dried extract possessed a high amount of tannins (417 µg/g), followed by flavonoids such as catechol (88 µg/g) and quercetin (9.2 µg/g). The antibacterial potential results revealed that only distilled water-based extraction techniques offered positive inhibition zones of 2.0-2.67 mm (MAE), 1.67-2.67 mm (UAE), and 1.67-2.17 mm (CSE) against all three organisms, while the chloroform based extracts had no inhibition effect. The microwave-assisted extract at 150 µl concentration offered a significant inhibitory effect against all three pathogens. The GC-MS profiling of bioactive compounds in flower extract revealed the presence of hexadecanoic acid as the major phytochemical compound in all three extraction techniques. The study revealed that the chloroform extract failed to exhibit an antibacterial effect due to the absence of alkaloids, saponins, and anthraquinones as a result of its neutralizing effect.

In this paper, the operational impact of three parameters including power of ultrasonic apparatus, size of fennel seeds and experiment time on the extraction yield of Anethole, which is the main considerable component in fennel essential oil and its concentration have been studied through Ultrasound-Assisted Extraction. The ultrasonic extraction of oil from fennel seeds using a solution of 70% water-ethanol was studied at different particle sizes, different ultrasonic powers and three different levels of time. The most effective parameter was particle size, while the experiment time had the least impact on both the efficiency and Anethole concentration as well. As a result, compared to Soxhlet method, the ultrasonic-assisted extraction was more efficient. In this experiment, eighteen constituents were identified for fennel seeds using GC–MS. The major components were Anethole (78.12%), Fenchone (8.81%), Limonene (4.39%), and Estragole (4.52%). Furthermore, the analysis of two quadratic models using the Box-Behnken design (BBD) indicated that the quadratic polynomial model can be applied for estimating the Anethole extraction yield as well as Anethole concentration.

In this paper, the operational impact of three parameters including power of ultrasonic apparatus, size of fennel seeds and experiment time on the extraction yield of Anethole, which is the main considerable component in fennel essential oil and its concentration have been studied through Ultrasound-Assisted Extraction. The ultrasonic extraction of oil from fennel seeds using a solution of 70% water-ethanol was studied at different particle sizes, different ultrasonic powers and three different levels of time. The most effective parameter was particle size, while the experiment time had the least impact on both the efficiency and Anethole concentration as well. As a result, compared to Soxhlet method, the ultrasonic-assisted extraction was more efficient. In this experiment, eighteen constituents were identified for fennel seeds using GC–MS. The major components were Anethole (78.12%), Fenchone (8.81%), Limonene (4.39%), and Estragole (4.52%). Furthermore, the analysis of two quadratic models using the Box-Behnken design (BBD) indicated that the quadratic polynomial model can be applied for estimating the Anethole extraction yield as well as Anethole concentration.

N-ethylcarbazole/dodecahydro-N-ethylcarbazole (NEC/12H-NEC) is one of the most attractive LOHCs, and it is of great significance to develop catalysts with high activity and reduce the hydrogen storage temperature. Layered double hydroxides-carbon nanotubes composites (LDH-CNT) were synthesized by a simple in-situ assembly method. Due to the introduction of CNT, a strong interaction occurred between LDH and CNT, which effectively improved the electron transfer ability of LDH-CNT. Ru/LDH-CNT catalysts were prepared via ultrasound-assisted reduction method without adding reducing agents and stabilizers. Under the cavitation effect of ultrasound, the hydroxyl groups on the surface of LDH were excited to generate hydrogen radicals (•H) with high reducibility, which successfully reduced Ru3+ to Ru NPs. Ru/LDH-3.9CNT-(300-1) catalyst was of 1.63 nm average Ru particle size with CNT amount of 3.9 wt% and the ultrasonic power of 300 W at 1 h, and its electron transfer resistance was less than that of Ru/LDH-(300-1). The synergy of ultrafine Ru NPs and fast electron transfer made it exhibit exceptional catalytic performance in NEC hydrogenation. Even if the reaction temperature was lowered to 80 °C, its hydrogenation performance was better than that of commercial Ru/Al2O3 catalyst at 120 °C. The ultrasound-assisted method is efficient, green and environmentally friendly, and the operation process is simple and economical. It is expected to be used in practical industrial production, which provides a reference for the preparation of high-activity and low-temperature hydrogen storage catalysts.

Plant proteins with improved solubility, foaming, and emulsifying properties are required to meet the demand for plant-based foods. This study evaluated the influence of alkaline extraction combined with enzyme- and ultrasound-assisted extraction on lentil protein structure and functionality. Enzyme- and ultrasound-assisted extractions were not capable of increasing the protein yield compared to alkaline extraction alone. However, the purity of isolated protein was dependent on the extraction process, ranging from 82.7% to 90%. Although the molecular mass, zeta potential profiles, and denaturation temperature were not dependent on the extraction method, the enthalpy of denaturation for protein obtained solely by alkaline extraction was significantly lower than that for assisted processes, indicating that protein denaturation is caused by an alkaline process. Changes in protein structure were also suggested by solubility analyses that showed that lentil proteins obtained by enzyme-assisted and ultrasound-assisted extraction have better solubility at pH 7 when compared to alkaline extraction alone. The surface activity of lentil protein was evidenced by interfacial and surface analysis, and it was influenced by the extraction process applied. We demonstrated that combining alkaline extraction with assisted processes, especially ultrasound technology, results in concentrates/isolates with higher solubility as compared to ones obtained solely by the traditional alkaline method, even though the choice of extraction method should depend on the desired functionality.

In this study, chitosan(CS), nano-silicon aerogels(nSA) and tea polyphenols(TP) were used as film-forming materials and processed with ultrasonication to form films using the tape-casting method. The effects of ultrasonication time, temperature and frequency on the properties of CS/nSA/TP film were explored via material property testing. The results of response surface showed that the maximum tensile strength of the film was 4.036 MPa at ultrasonication time(57.97 min), temperature(37.26 °C) and frequency(30 kHz). The maximum elongation at break of the film was 279.42 % at ultrasonication time(60.88 min), temperature(39.93 °C) and frequency(30 kHz). Due to cavitation and super-mixing effects, ultrasonication may make the surface of the film smoother and easier to degrade. After ultrasonication, TPs were protected by the 3D network structure composed of CS and nSA. Ultrasonication improved the antioxidant and antibacterial properties of the film. These results show that ultrasonication is an effective method to improve the properties of films.

Cyclodextrin metal–organic framework by ultrasound-assisted rapid synthesis for caffeic acid (CA) loading and antibacterial application (U-CD-MOF) was successfully studied and this method shortened the preparation time to a few minutes. It was found that the ultrasonic power, reaction time and temperature would affect the morphology and size of the obtained crystal. Under the optimal conditions, U-CD-MOF had a cubic structure with uniform size of 8.60 ± 1.95 μm. U-CD-MOF was used to load the antibacterial natural product CA to form the composite (CA@U-CD-MOF) and the loading rate of CA@U-CD-MOF to CA could reach 19.63 ± 2.53%, which was more than twice that of γ-CD. Various techniques were applied to characterize the synthesized crystal, including Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and N2 adsorption. In addition, antibacterial tests were performed on the obtained crystal. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CA@U-CD-MOF for Escherichia coli O157: H7 (E. coli O157: H7) were both 25 mg·mL−1, and the MIC for Staphylococcus aureus (S. aureus). was 25 mg·mL−1. The sustained release behavior of CA@U-CD-MOF to CA in ethanol fitted well to Higuchi model and the loading of CA was supported by molecular docking results. In general, U-CD-MOF was successfully achieved by ultrasound-assisted rapid synthesis and the obtained crystal was further evaluated for potential antibacterial application.

According to the advantages of ultrasonic vibration cutting, an ultrasound-assisted corneal trepanation robotic system is developed to improve the accuracy of corneal trephination depth and corneal incision quality in corneal trephination operations. Firstly, we analyzed the reasons for the difficulty in controlling the depth of trephination in corneal transplantations from the perspective of the biomechanical properties of the cornea. Based on the advantages of ultrasonic vibration cutting, we introduced an ultrasonic-vibration-assisted cutting method for corneal trephination and analyzed the cutting mechanism. Secondly, we described the surgical demands of corneal trephination and listed the design requirements of a robotic system. Thirdly, we introduced the design details of said system, including the system’s overall structure, the ultrasound-assisted end effector, the key mechanisms of the robotic system, and the human–machine interaction interface. We designed the end effector based on ultrasonic vibration cutting and its eccentric adjustment system in an innovative way. Additionally, we then presented a procedure for robot-assisted corneal trephination. Finally, we performed several cutting experiments on grapes and porcine eyeballs in vitro. The results show that, compared with manual trephine, ultrasound-assisted corneal trephination has a better operation effect on the accuracy of corneal trephination depth and corneal incision quality.

Synthesis of ethyl acetate (EA) using lipase as a catalyst, as an environmentally-friendly process, has attracted considerable attention. However, the slow rate of enzymatic reaction and higher cost limit its applications. Ultrasound irradiation (UI) is known as an effective tool for accelerating the rate of enzymatic reaction under mild conditions. To attain maximum yield, it is crucial to understand the effect of UI on EA synthesis and the underlying mechanism. Therefore, the present study investigated the effect of UI on lipase-catalyzed ethyl acetate synthesis. The results clearly demonstrated that UI could remarkably accelerate the process of lipase-catalyzed synthesis of ethyl acetate compared with mechanical shaking. The optimal conditions of ultrasound-assisted reaction by using Novozyme 435® were 6% enzyme loading, 4:1 molar ratio of ethanol to acetic acid, 150 W & 28 kHz ultrasonic power and frequency, respectively. Bi-bi ping-pong model was employed to give a deep insight into the underlying mechanism of the beneficial effect of UI. It was found that Vmax under UI was elevated by 143% compared with that under mechanical shaking. Application of UI could decrease Kacetic acid and Ki ethanol while increase Kethanol and Ki acetic acid. In conclusion, the present study addresses that UI could remarkably accelerate the process of lipase-catalyzed synthesis of EA compared with mechanical shaking, and kinetic model results explained why ultrasound can significantly speed up lipase catalyzed synthesis of ethyl acetate, which may help to improve the industrial application potential of ethyl acetate biosynthesis.

The discovery of a green extraction solvent for natural plants could promote related research. In this study, deep eutectic solvents (DES) were used as green solvents coupled with an ultrasound-assisted extraction method (UAE) to extract flavonoids from lotus leaves. Thirty-four different DES were performed and choline chloride/urea with 40% water was chosen as the most promising one, and the related parameters in the procedures were optimized, resulting in the highest extraction amount of flavonoids in lotus leaves. D-101 was selected from four macroporous resins to separate the flavonoids from DES. Moreover, DES could be recycled and efficiently reused four times with satisfactory performances. In addition, the lotus leaf flavonoids from the DES extract exhibited antioxidant activities in five kinds of assays including DPPH, ABTS, Fe3+ reducing, FRAP, and Fe2+ chelating. It also showed antibacterial activities on Staphylococcus aureus and Escherichia coli bacterial strains with minimal inhibitory concentrations at 1666 μg/mL and 208 μg/mL, respectively. In the HPLC analysis, the three main components in the DES extract were identified as astragalin, hyperoside, and isoquercitrin. In conclusion, the developed UAE-DES followed by macroporous resin treatment could become an efficient and environmentally friendly extraction and enrichment method for flavonoids from lotus leaves and other natural products.

In this study, ultrasonic-assisted cellulase extraction (UCE) was applied to extract flavonoids and polyphenols from the Nymphaea hybrid flower. The extraction conditions were optimized using the response surface method (RSM) coupled with a Box-Behnken design. The crude extract of Nymphaea hybrid (NHE) was further purified using AB-8 macroporous resins, and the purified extract (NHEP) was characterized by FTIR and HPLC. In vitro activity determination by chemical method showed that NHEP displayed strong free radical scavenging abilities against the DPPH and ABTS radicals, good reduction power, and hyaluronidase inhibition. The cell viability by CCK-8 assays showed that NHEP had no significant cytotoxicity for B16 and HaCaT cells when the concentration was below 100 μg/mL and 120 μg/mL, respectively. NHEP with a concentration of 20–160 μg/mL can more effectively reduce the ROS level in H2O2 damaged HaCaT cells compared with 10 μg/mL of VC. The 40 μg/mL of NHEP had similar activity against intracellular melanin production in the B16 melanoma cells compared with 20 μg/mL Kojic acid. Good activities of antioxidation, whitening and protective effect against H2O2-induced oxidative damage promote the potential for NHEP as a functional raw material in the field of cosmetics and medicine.

The preparation and characterization of biodegradable films based on starch-PVA-nanoclay by solvent casting are reported in this study. The films were prepared with a relation of 3:2 of starch:PVA and nanoclay (0.5, 1.0, and 1.5% w/v), and glycerol as plasticizer. The nanoclays before being incorporated in the filmogenic solution of starch-PVA were dispersed in two ways: by magnetic stirring and by sonication. The SEM results suggest that the sonication of nanoclay is necessary to reach a good dispersion along the polymeric matrix. FTIR results of films with 1.0 and 1.5% w/v of sonicated nanoclay suggest a strong interaction of hydrogen bond with the polymeric matrix of starch-PVA. However, the properties of WVP, tensile strength, percentage of elongation at break, and Young’s modulus improved to the film with sonicated nanoclay at 0.5% w/v, while in films with 1.0 and 1.5% w/w these properties were even worse than in film without nanoclay. Nanoclay concentrations higher than 1.0 w/v saturate the polymer matrix, affecting the physicochemical properties. Accordingly, the successful incorporation of nanoclays at 0.5% w/v into the matrix starch-PVA suggests that this film is a good candidate for use as biodegradable packaging.

In order to extract antioxidant phenolic compounds from spent grain (SG) two extraction methods were studied: the ultrasound-assisted method (US) and the Ultra-Turrax method (high stirring rate) (UT). Liquid to solid ratios, solvent concentration, time, and temperature/stirring rate were optimized. Spent grain extracts were analyzed for their total phenol content (TPC) (0.62 to 1.76 mg GAE/g SG DW for Ultra-Turrax pretreatment, and 0.57 to 2.11 mg GAE/g SG DW for ultrasound-assisted pretreatment), total flavonoid content (TFC) (0.6 to 1.67 mg QE/g SG DW for UT, and 0.5 to 1.63 mg QE/g SG DW for US), and antioxidant activity was measured using 2,2-diphenyl-2-picrylhydrazyl (DPPH) free radical (25.88% to 79.58% for UT, and 27.49% to 78.30% for UT). TPC was greater at a high stirring rate and high exposure time up to a certain extent for the Ultra-Turrax method, and at a high temperature for the ultrasound-assisted method. P-coumaric acid (20.4 ± 1.72 mg/100 SG DW for UT, and 14.0 ± 1.14 mg/100 SG DW for US) accounted for the majority of the phenolic found compounds, followed by rosmarinic (6.5 ± 0.96 mg/100 SG DW for UT, and 4.0 ± 0.76 mg/100 SG DW for US), chlorogenic (5.4 ± 1.1 mg/100 SG DW for UT, and non-detectable for US), and vanillic acids (3.1 ± 0.8 mg/100 SG DW for UT, and 10.0 ± 1.03 mg/100 SG DW for US) were found in lower quantities. Protocatechuic (0.7 ± 0.05 mg/100 SG DW for UT, and non-detectable for US), 4-hydroxy benzoic (1.1 ± 0.06 mg/100 SG DW for UT, and non-detectable for US), and caffeic acids (0.7 ± 0.03 mg/100 SG DW for UT, and non-detectable for US) were present in very small amounts. Ultrasound-assisted and Ultra-Turrax pretreatments were demonstrated to be efficient methods to recover these value-added compounds.

The freshwater mussel protein was hydrolysed using ultrasound-assisted enzymolysis. Ultrasound-assisted freshwater mussel protein hydrolysates (UPH) were divided into four fractions (> 10, 6-10, 3-6, and < 3 kDa) using ultrafiltration, and the fraction with the highest antioxidant activity was further subdivided into four fractions (F1-F4) using gel chromatography. The amino acid compositions and antioxidant activities (DPPH, hydroxyl and superoxide radical scavenging activities, reducing power, ferrous ion chelating activity, and inhibition of linoleic acid oxidation) of peptide fractions were investigated. The results showed that the antioxidant activity of the < 3 kDa fraction was significantly higher than that of UPH, > 10, 6-10, and 3-6 kDa fractions. The antioxidant activity of F2 was again higher compared with the < 3 kDa fraction and higher than that of F1, F3, and F4. Amino acid analysis showed that the antioxidant activities (except for chelating activity) of peptides increased with increasing hydrophobic amino acid content. The < 3 kDa and F2 fractions exhibited strong inhibition of linoleic acid oxidation, their effects being even better than that of ascorbic acid (Vc) and l-glutathione (GSH). Therefore, these peptide fractions from freshwater mussel may be a potential natural antioxidant that could be added to various foods.

Ultrasound-assisted melt-extrusion method (USME) is a high-quality process used to produce polymeric compounds with an adequate homogeneous dispersion. This study evaluates white-color films of linear low-density polyethylene (LLDPE) prepared using TiO2 masterbatch obtained by ultrasound-assisted melt-extrusion at variable frequencies (USME-VF). LLDPE with three different melt-flow indices (2, 20 and 50 g/10 min) were used as the polymer matrix. The films were obtained from the dilution of masterbatches of LLDPE (melt-flow index = 2) at a concentration of 7 wt% TiO2. The morphology, pigmentation, TiO2 reactivity, and the mechanical stability of the films were assessed. The masterbatch compounds were evaluated by melt-flow index (MFI) and scanning electron microscopy (SEM). The contrast ratio, yellowness index and mechanical properties of films were also measured. The properties of whiteness and elongation at break improved in the films prepared using masterbatches with higher dispersion. Though the reactivity of the TiO2 particles increased during accelerated aging, it did not affect the elongation to rupture. The yellowness index was moderately affected in films that included TiO2 particles processed using USME-VF.

In this work ultrasound-assisted solid-state enzymatic hydrolysis of rice bran to obtain fermentable sugars was investigated. For this purpose, process variables such as temperature, enzyme concentration and moisture content were evaluated during the enzymatic hydrolysis with and without ultrasound irradiation. The enzyme used is a blend of amylases derived from genetically modified strains of Trichoderma reesei. Kinetic of the enzymatic hydrolysis of rice bran at the constant-reaction rate period were measured. The best results for the ultrasound-assisted enzymatic hydrolysis was obtained using 3 wt% of enzyme, 60 oC and moisture content of 65 wt%, yielding 0.38 g sugar/g rice bran, whereas for the hydrolysis in the absence of ultrasound the highest yield was 0.20 g sugar/g rice bran using 3 wt% of enzyme, 60 oC and moisture content of 50 wt%. The use of ultrasound-assisted enzymatic hydrolysis of rice bran was intensified, obtaining around 74% more fermentable sugar than in the absence, showing that the use of ultrasound is a promising technology to be used in enzymatic reaction as an alternative of process intensification.

A facile synthesis of hitherto unreported 3-(2-benzofuroyl)carbazoles 3a–k, 3,6-bis(2-benzofuroyl)carbazoles 5a–k, and naphtho[2,1-b]furoylcarbazoles 3l and 5l is described. The synthesis mainly relies on the ultrasound-assisted Rap–Stoermer reaction of 3-chloroacetyl- (1) or 3,6-dichloroacetyl-9-ethyl-9H-carbazole (4) with various salicylaldehydes 2a–k as well as 2-hydroxy-1-naphthaldehyde (2l) in CH3CN with the presence of PEG-400 as catalyst. The procedure offers easy access to benzofuroylcarbazoles in short reaction times and the products are obtained in moderate to good yields.

Molecular imprinting is a powerful technology to create artificial receptors within polymeric matrices. Although it was reported for the first time by Polyakov, eighty-four years ago, it remains, nowadays, a very challenging research area. Molecularly imprinted polymers (MIPs) have been successfully used in several applications where selective binding is a requirement, such as immunoassays, affinity separation, sensors, and catalysis. Conventional methods used on MIP production still use large amounts of organic solvents which, allied with stricter legislation on the use and release of chemicals to the environment and the presence of impurities on final materials, will boost, in our opinion, the use of new cleaner synthetic strategies, in particular, with the application of the principles of green chemistry and engineering. Supercritical carbon dioxide, microwave, ionic liquids, and ultrasound technology are some of the green strategies which have already been applied in MIP production. These strategies can improve MIP properties, such as controlled morphology, homogeneity of the binding sites, and the absence of organic solvents. This review intends to give examples reported in literature on green approaches to MIP development, from nano- to micron-scale applications.