High-intensity Ultrasound Technology Research Articles

One-step ultrasound-assisted recovery of yellow-orange-red natural coloring from defatted annatto seeds: A cleaner processing alternative

The interest in natural colorants derived from sustainable processes has prompted research into obtaining bixin from defatted annatto (Bixa orellana L.) seeds. Bixin is a compound that imparts yellow-orange-red coloration, known for its high biodegradability, low toxicity, and wide industrial applicability. Meanwhile, high-intensity ultrasound (HIUS) technology has emerged as a promising method for extracting natural colorants, offering higher yields through shorter processes and minimizing thermal degradation. Although some studies have demonstrated the efficiency of HIUS technology in bixin extraction, research on the effects of acoustic cavitation on the properties of the colorant remains limited. Therefore, this study aimed to investigate the influence of HIUS-specific energy levels (0.02, 0.04, 0.12, and 0.20 kJ/g) on the chemical, physical, and morphological characteristics of annatto extracts containing bixin and geranylgeraniol. Single-step extractions of bixin using ethanol as a solvent were evaluated at various acoustic powers (4.6, 8.5, 14.5, and 20 W) and extraction times (0.5, 1, 3, and 5 min) to determine their impact on the yield of natural colorant extraction. Increasing the acoustic power from 4.6 to 20 W and extending the extraction time from 0.5 to 5 min resulted in higher yields of natural colorant, likely due to the effects of acoustic cavitation and increased heat under more intense conditions. However, elevated levels of mechanical and thermal energy did not affect the chemical properties of the colorant, as indicated by UV–Vis and FTIR spectra. Conversely, higher specific energies yielded colorants with a more intense red hue, consistent with increased bixin content, and altered the microstructure and physical state, as observed in X-ray diffractograms. Nevertheless, these alterations did not impact the solubility of the colorant. Therefore, employing a cleaner extraction procedure aided by one-step ultrasound facilitated the recovery of natural colorants and contributed to the biorefining of annatto seeds, enabling the production of a rich geranylgeraniol colorant through a sustainable approach.

High-intensity ultrasound-based process strategies for obtaining edible sunflower (Helianthus annuus L.) flour with low-phenolic and high-protein content

The sunflower Helianthus annuus L. represents the 4th largest oilseed cultivated area worldwide. Its balanced amino acid content and low content of antinutrient factors give sunflower protein a good nutritional value. However, it is underexploited as a supplement to human nutrition due to the high content of phenolic compounds that reduce the sensory quality of the product. Thus, this study aimed at obtaining a high protein and low phenolic compound sunflower flour for use in the food industry by designing separation processes with high intensity ultrasound technology. First, sunflower meal, a residue of cold-press oil extraction processing, was defatted using supercritical CO2 technology. Subsequently, sunflower meal was subjected to different conditions for ultrasound-assisted extraction of phenolic compounds. The effects of solvent composition (water: ethanol) and pH (4 to 12) were investigated using different acoustic energies and continuous and pulsed process approaches. The employed process strategies reduced the oil content of sunflower meal by up to 90% and reduced 83% of the phenolic content. Furthermore, the protein content of sunflower flour was increased up to approximately 72% with respect to sunflower meal. The acoustic cavitation-based processes using the optimized solvent composition were efficient in breaking down the cellular structure of the plant matrix and facilitated the separation of proteins and phenolic compounds, while preserving the functional groups of the product. Therefore, a new ingredient with high protein content and potential application for human food was obtained from the residue of sunflower oil processing using green technologies.

Consumers’ attitudes of high-intensity ultrasound in Minas Frescal cheese processing: An innovative approach with text highlighting technique

Due to the intense competition in the sector, the dairy market maintains a constant search for innovations. Thus, new technologies are incorporated, and new products are constantly launched, increasing the range of consumer options. In this way, the understanding of consumers' motivations, attitudes, and behaviors in the moments of choice, purchase, and consumption are important for the academic public and food industries. This study used the Text Highlighting methodology to assess Brazilian consumers' explicit attitudes towards using high-intensity ultrasound technology in Minas Frescal cheese processing. In the task, consumers were asked to highlight in a text the terms they “liked” or “disliked” about using high-intensity ultrasound in the Minas Frescal cheese processing. A seven-point Likert scale was also used to assess consumers' attitudinal statements. A high engagement of consumers with the Text Highlighting methodology could be observed (43.8–92.3% of text highlighting), which suggests good intuitiveness of the technique. Including information about the benefits of the emerging technology in the product, mainly on sensory and nutritional properties, may increase positive consumer perception, as it promotes the consumers to express their value judgment in the form of “liked”. At the same time, the harms of the traditional processing technique prompted consumers to express their value judgment in the “disliked” highlights. It was observed that information should be in a simple and direct language, as technical terminology in the text did not have a positive effect. The categorizing of consumers according to the sentimental score showed that consumers are still reticent to use emerging technologies in Minas Frescal cheese processing. Consumers' attitudinal statements demonstrated that consumers perceive high-intensity ultrasound as a positive idea and safety technology for Minas Frescal cheese processing. Still, they are not willing to pay premium prices. In conclusion, Text Highlighting produced valuable insights that can be used in communication strategies with Minas Frescal cheese consumers.

High-intensity ultrasound-assisted recovery of anthocyanins from jabuticaba by-products using green solvents: Effects of ultrasound intensity and solvent composition on the extraction of phenolic compounds

This study proposes an update for the jabuticaba processing chain to obtain valuable coproducts from jabuticaba peels. High-intensity ultrasound (HIUS) technology was evaluated as a more efficient extraction process to obtain two high added-value coproducts: pectin and an anthocyanins-rich extract. The HIUS-assisted extraction of bioactive compounds like anthocyanins from the jabuticaba peels was evaluated. The effects of ultrasound intensity (1.1, 3.7, 7.3, and 13.0 W/cm2) and solvent composition concerning water/ethanol ratio (0, 25, 50, 75, and 100 g water/100 g) were examined. One-step HIUS processing promoted the best recovery of bioactive compounds at an ultrasound intensity of 3.7 W/cm2 and 50 g water/100 g, thus proofing the interaction between ultrasound intensity and the solvent composition has a strong influence on the extraction efficiency of the groups of compounds studied and in the jabuticaba peel antioxidant potential. The confocal laser scanning microscopy confirmed bioactive compounds' exhaustion in the dried jabuticaba peel after the HIUS processing, proving its best recovery. The jabuticaba peel extract exhibited an intense reddish color typical of anthocyanin-rich products at acid pH (4.5). The HIUS technology turned out a promising way to recover these valuable phenolic compounds as a quick, relatively inexpensive, and simple technology that improves the yields and decreases the costs and environmental impacts compared to conventional extraction processes.

A techno-economic evaluation for the genipin recovery from Genipa americana L. employing non-thermal and thermal high-intensity ultrasound treatments

This paper presents techno-economic results for the high-intensity ultrasound (HIUS)-assisted extraction of a valuable phytochemical. Genipin is a precussor of natural blue compounds besides presenting anticancer, anti-oxidative, and anti-inflammatory properties. The effects of the non-thermal and thermal HIUS treatments on obtaining of genipin-rich ethanolic extracts from the unripe Genipa americana L. were evaluated. The HIUS treatments were evaluated in the economic viewpoint to show their feasibility in different scenarios. The non-thermal HIUS-assisted extraction, with a maximum temperature of 30 ± 1 °C, was performed applying a nominal power of 100 W and the thermal extraction with 450 W, achieving a maximum temperature of 73 ± 1 °C. For both treatments, the HIUS specific energy levels of 1, 3, and 5 kJ/g were assessed. The unripe genipap extracts obtained were characterized during their storage time (0, 24, 48, and 72 h) at 24 ± 2 °C according to their genipin and geniposide content and visual appearance. The cost of manufacturing was evaluated in a pilot and industrial-scale for the different HIUS treatments studied. Our results demonstrated that the HIUS-assisted extractions allowed us to obtain different amounts of genipin and geniposide according to the non-thermal and thermal process conditions. The more intense acoustic cavitation provided by the nominal power of 450 W resulted in a better diffusion and, consequently, higher genipin recovery. The economic evaluation showed different scenarios to produce genipin-rich ethanolic extracts by HIUS technology. In comparison with a process using pressing + low-pressure extraction, our HIUS processes presented a faster and fixed capital investment two times cheaper.

Xylooligosaccharides chemical stability after high-intensity ultrasound processing of prebiotic orange juice.

The effects of the high-intensity ultrasound (HIUS) technology at the nominal powers of 300, 600, 900, and 1200W were evaluated on the chemical stability of xylooligosaccharides (XOS) used to enrich orange juice. The ultrasound energy performance for each nominal power applied to the XOS-enriched orange juice was determined by calculating acoustic powers (W), HIUS intensity (W/cm2), and energy density (kJ/mL). Physicochemical properties (pH and soluble solid content), organic acid content (ascorbic, malic, and citric acids), total phenolic content (TPC), antioxidant activity by the FRAP (Ferric reducing ability of plasma) method, sugar (glucose, fructose, and sucrose), and XOS (xylobiose, xylotriose, xylotetraose, xylopentaose, and xylohexaose) content were determined. The pH and soluble solid content did not change after all HIUS treatments. The HIUS process severity was monitored by quantifying ascorbic acid content after the treatments. A significant linear decrease in the ascorbic acid content was observed in prebiotic orange juice with the HIUS process intensification by increasing nominal power. The malic acid and citric acid contents had similar behavior according to the HIUS process intensification. The nominal power increase from 300 to 600W increased the concentration of both organic acids, however, the intensification up to 1200W reduced their concentration in the functional beverage. The TPC and FRAP data corroborated with the results observed for the ascorbic acid content. However, the HIUS processing did not alter sugar and XOS contents. The XOS chromatographic profiles were not modified by the HIUS treatment and presented the same amount of all prebiotic compounds before and after the HIUS treatment. Overall, HIUS technology has been evaluated as a promising stabilization technique for prebiotic beverages enriched with XOS due to their high chemical stability to this emerging technology under severe process conditions.

High-intensity ultrasound energy density: How different modes of application influence the quality parameters of a dairy beverage.

This study evaluated the influence of the high-intensity ultrasound (HIUS) technology on the quality parameters of a model dairy beverage (chocolate whey beverage), operating under the same energy density (5000J/mL), but applied at different ways. Two processes were performed varying nominal power and processing time: HIUS-A (160W and 937s), and HIUS-B (720W and 208s). Our objective was to understand how different modes of application of the same HIUS energy density could influence the microstructure, droplet size distribution, zeta potential, phase separation kinetic, color parameters and mineral profile of the chocolate whey beverage. The results demonstrated that the different modes of application of the same HIUS energy density directly influenced the final quality of the product, resulting in whey beverages with distinct physical and microstructural characteristics. The HIUS-B processing was characterized as a thermal processing, since the final processing temperature reached 71°C, while the HIUS-A processing was a non-thermal process, reaching a final temperature of 34°C. Moreover, HIUS-B process greatly reduced the droplet size and increased the lightness value in relation to the HIUS-A processing. Both treatments resulted in whey beverages with similar phase separation kinetics and were more stable than the untreated sample. The HIUS processes did not modify the mineral content profile. Overall, the study emphasizes the versatility of the HIUS technology, highlighting that the processing must not be based only on the applied energy density, since different powers and processing times produce dairy beverages with distinct characteristics.

Clove essential oil emulsion-filled cellulose nanofiber hydrogel produced by high-intensity ultrasound technology for tissue engineering applications.

High-intensity ultrasound (HIUS) was used to produce emulsion-filled cellulose nanofiber (CNF) hydrogel using clove essential oil (0.1, 0.5 and 1.0 wt%) as dispersed phase towards tissue engineering applications. The novel encapsulating systems obtained using HIUS specific energy at the levels of 0.10, 0.17, and 0.24 kJ/g were characterized by oil entrapment efficiency, microstructure, water retention value, color parameters, and viscoelastic properties. Freeze-dried emulsion-filled CNF hydrogels were characterized by porosity and swelling capacity. In addition, human gingival fibroblast cell cytocompatibility tests were performed to evaluate their potential applications as tissue engineering scaffold. The clove essential oil content strongly affected the oil entrapment efficiency, water retention value, color difference and whiteness of the prepared emulsion-filled CNF hydrogel. And, the HIUS energy only affected the yellowness of the emulsion-filled CNF hydrogel. Via HIUS processing, the CNF hydrogel successfully acted as a continuous phase in the emulsion-filled gel system with maximum oil entrapment efficiency of 34% when 0.5 wt% clove essential oil was added to the system. The encapsulating systems had predominantly gel-like property with maximum elastic modulus of 411 Pa. Furthermore, the emulsion-filled CNF hydrogels with the addition of clove essential oil up to 0.5 wt% indicated good cell viability rates (74-101%) to human gingival fibroblast cells. The newly developed clove essential oil emulsion-filled CNF hydrogel shows desirable cytocompatibility characteristics and can be considered as an alternative scaffold for tissue engineering applications.

High-intensity ultrasound-assisted formation of cellulose nanofiber scaffold with low and high lignin content and their cytocompatibility with gingival fibroblast cells.

Cellulose nanofiber (CNF) hydrogels with low lignin (8%) (LL-CNF) and high lignin (18%) (HL-CNF) content were produced at nominal powers of 240, 720 and 1200 W using high-intensity ultrasound technology (HIUS). Freeze-dried CNF hydrogels were evaluated as scaffolds for gingival fibroblast cells proliferation aiming biomedical applications. HIUS processing improved the dispersibility of the CNF and increased the water retention value by more than 5 times. The LL-CNF had a maximum fibrillation yield of 46 wt.%, whereas the HL-CNF had a maximum fibrillation yield of 40 wt.% at nominal power of ≥720 W. Regardless of the lignin content, the CNF hydrogels exhibited a typical elastic gel-like behavior with the highest elasticity of 263 Pa. After freeze-drying, the CNF aerogels had porosity ≥ 96.8%, and swelling capacity up to 42.1 g PBS/g aerogel. Moreover, the cell proliferation assay showed no differences in proliferation among the LL-CNF and HL-CNF scaffolds up to 11 days. Therefore, CNF scaffolds prepared with lignin content up to 18% present promising application in the biomedical field.

Effect of high-intensity ultrasound on the nutritional profile and volatile compounds of a prebiotic soursop whey beverage

This study evaluated the nutritional profile and volatile compounds present in a novel prebiotic (inulin) soursop whey beverage, due to the effects of high-intensity ultrasound (HIUS). The prebiotic soursop whey beverage was produced and processed by non-thermal high-intensity ultrasound varying the power (0, 200, 400 and 600 W) and by high-temperature short time (72 °C for 15 s) thermal treatment. Total acidity, pH, ascorbic acid content, total phenolics compounds content, antioxidant activity, hypertensive activity, fatty acid profile, volatile organic compounds, macro and micro minerals, as well as the heavy metals in these products, were analyzed. Overall, the HIUS technology induced some positive changes in the nutritional profile of the soursop whey beverage including beneficial effects, e.g., increase of phenolic content, improvement of the antioxidant and anti-hypertensive activity and reduction of undesired minerals. Although some negative changes, such as degradation of the ascorbic acid, decrease of some minerals and production of certain volatile compounds were found, the beneficial effects were prominent, thus, opening new opportunities to develop healthy functional beverages.

Processing of inulin-enriched apple juice using high-intensity ultrasound technology

The effects of high-intensity ultrasound (HIUS) processing on chemical composition of inulin-enriched apple juice were evaluated at different specific energy levels (0, 1, 4, 7 and 10 kJ/g). The functional beverage was characterized with respect to fructooligosaccharides (FOS) and total sugars content. In addition, the inulin chemical profile was evaluated. The analysis of sugars and fructo-oligosaccharides in the functional juice was performed by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD).

Effects of high-intensity ultrasound process parameters on the phenolic compounds recovery from araticum peel

In this work, we investigated the effects of the nominal ultrasonic power (160–640 W) and process time (0.5–5.0 min) on the phenolic compounds recovery and antioxidant activity from araticum peel. The individual and synergistic effects of the process variables on the phenolic recovery were estimated using a full factorial experimental design. Operating at high nominal ultrasonic powers was possible to obtain high phenolic yields and antioxidant activities at short process times (≤5 min). The HPLC-ESI-QTOF-MS/MS analysis revealed that the araticum peel sample possessed 142 phytochemicals, 123 of which had not been reported in the literature for this raw material yet. The most abundant phenolic compounds recovered were epicatechin, rutin, chlorogenic acid, catechin and ferulic acid. Thus, high-intensity ultrasound technology proved to be a simple, efficient, fast and low environmental impact method for obtaining phenolic compounds from araticum peel. In addition, araticum peel showed to be a promising source bioactive natural phenolics for further applications in the food, nutraceutical, cosmetic and pharmaceutical industries.

High intensity ultrasound treatment of faba bean (Vicia faba L.) protein: Effect on surface properties, foaming ability and structural changes

Response surface methodology was used for establishing the amplitude (72.67%) and time (17.29 min) high-intensity ultrasound (HIUS) conditions leading to an optimized faba bean protein isolate (OFPI) with lower interfacial tension, zeta potential and viscosity, and higher solubility than native faba bean protein isolate (NFPI). OFPI showed significantly higher adsorption dynamics at the air-water interface, and produced foam with significant smaller bubble diameter, higher overrun, stability and yield stress, and lower liquid drainage than NFPI. Fourier Transform Spectroscopy (FT-IR) revealed that the secondary structure of OFPI deferred from NFPI in terms of increases in β conformations (6.61% β-sheet, 19.6% β-turn, 0.8% anti-parallel β-sheet) and decreases in inter-molecular aggregates (43.54%). Multienzyme study pinpointed that the structural changes could have induced a decrease on the relative protein digestibility of OFPI respect that of NFPI. The results of this work demonstrate that HIUS technology improves the surface and foaming properties of faba bean protein isolate, which may favour the revalorisation of this crop.

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 (20kHz) and ultrasound bath (40kHz) for 5, 10, 20 and 30min. Thermal stability of protein isolates was reduced as indicated by differential scanning calorimetry. Minimum thermal stability was observed at 20min 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.

Biological Effects of Low Frequency High Intensity Ultrasound Application on EX Vivo Human Adipose Tissue

In the present work the effects of a new low frequency, high intensity ultrasound technology on human adipose tissue ex vivo were studied. In particular, we investigated the effects of both external and surgical ultrasound-irradiation (10 min) by evaluating, other than sample weight loss and fat release, also histological architecture alteration as well apoptosis induction. The influence of saline buffer tissue-infiltration on the effects of ultrasound irradiation was also examined. The results suggest that, in our experimental conditions, both transcutaneous and surgical ultrasound exposure caused a significant weight loss and fat release. This effect was more relevant when the ultrasound intensity was set at 100 % (~2.5 W/cm², for external device; ~19-21 W/cm2, for surgical device) compared to 70 % (~1.8 W/cm² for external device; ~13-14 W/cm2 for surgical device). Of note, the effectiveness of ultrasound was much higher when the tissue samples were previously infiltrated with saline buffer, in accordance with the knowledge that ultrasonic waves in aqueous solution better propagate with a consequently more efficient cavitation process. Moreover, the overall effects of ultrasound irradiation did not appear immediately after treatment but persisted over time, being significantly more relevant at 18 h from the end of ultrasound irradiation. Evaluation of histological characteristics of ultrasound-irradiated samples showed a clear alteration of adipose tissue architecture as well a prominent destruction of collagen fibers which were dependent on ultrasound intensity and most relevant in saline buffer-infiltrated samples. The structural changes of collagen bundles present between the lobules of fat cells were confirmed through scanning electron microscopy (SEM) which clearly demonstrated how ultrasound exposure induced a drastic reduction in the compactness of the adipose connective tissue and an irregular arrangement of the fibers with a consequent alteration in the spatial architecture. The analysis of the composition of lipids in the fat released from adipose tissue after ultrasound treatment with surgical device showed, in agreement with the level of adipocyte damage, a significant increase mainly of triglycerides and cholesterol. Finally, ultrasound exposure had been shown to induce apoptosis as shown by the appearance DNA fragmentation. Accordingly, ultrasound treatment led to down-modulation of procaspase-9 expression and an increased level of caspase-3 active form.

Transcranial Focused Ultrasound Surgery

The development of high-intensity ultrasound technology into a system for performing image-guided noninvasive ultrasound neurosurgery has developed at a relatively rapid pace in the past few years. Magnetic resonance imaging has contributed significantly to this development by providing a modality by which percutaneous ultrasound treatments can be preoperatively planned, intraoperatively guided and postoperatively evaluated for safety and efficacy. Especially in the case of transcranial ultrasound therapies, the structural identification and thermal monitoring of cortical structures is essential to avoid overheating at the skull-brain interface and to avoid the sonication of critical structures. This chapter briefly describes the physics of transmitting ultrasound through the skull and the technological advances that circumvented the physical limits imposed by the skull bone. The integration of magnetic resonance guidance and monitoring is detailed, along with an overview of ongoing studies with a commercially developed magnetic resonance imaging-compatible hemispherical transducer array.