High-intensity Ultrasounds Research Articles

Enhancement of foaming property of ormosia protein: Insights into the effect of high-intensity ultrasound on physicochemical properties and structure analysis

Ormosia, as one of the consumer's favorite grains, is rich in protein, but its application is limited by the naturally low solubility of its protein. In order to improve its application capability, the Ormosia protein (OSP) is modified by high-intensity ultrasounds (HIUS), and the effect of ultrasound on the secondary and tertiary structure, as well as the improvement of its foaming property due to the alteration in protein structure, were systematically explored. It has been observed that HIUS greatly reduced the particle size of the OSP, and significantly affected the secondary and tertiary structure. These fundamental changes improved the ability of the OSP to stabilize foam at the water-air interface, and thus the HIUS-treated OSP possessed an excellent foaming property. The results of this study are expected to provide a theoretical basis for expanding the application of the OSP in the food industry.

High-intensity ultrasound treatment on casein: Pea mixed systems: Effect on gelling properties.

This study aimed to investigate the suitability of the application of high-intensity ultrasounds (HIUS) to improve the acid induced gelation of mixed protein systems formed by casein micelles (CMs) and pea. The protein suspensions were prepared in different protein ratios CMs: pea (100:0, 80:20, 50:50, 20:80, 0:100) at 8% (w/w) total protein concentration. In the suspensions, the ultrasound treatment produced an increase in solubility, surface hydrophobicity, and a decrease in the samples' viscosity, with more remarkable differences in protein blends in which pea protein was the major component. However, the replacement of 20% of CMs for pea proteins highly affected the gel elasticity. Hence, the creation of smaller and more hydrophobic building blocks before acidification due to the HIUS treatment increased the elasticity of the gels up to 10 times. Therefore, high-intensity ultrasounds are a suitable green technique to increase the gelling properties of CMs: pea systems.

The Effects of a High-Intensity Ultrasound on the Fermentative Activity and Kinetic Growth of Lactobacillus Acidophilus and Lactobacillus Helveticus

An ultrasound, a non-thermal technique, can be employed to increase a probiotic’s biomass and its fermentation products. The effects of high-intensity ultrasounds (20%, 30%, and 40% amplitudes for 3 min) on the growth and fermentative profile of Lactobacillus acidophilus and helveticus were studied. The use of an ultrasound decreased the Lag phase and increased the maximum growth potential; however, the effect depended on the amplitude used. For both probiotics, the β-galactosidase activity increased in the treatments with a 20% amplitude—3 min and 30% amplitude—but decreased in the treatment with a 40% amplitude—3 min in comparison to the values found in the control treatment. The two probiotics showed a decrease in the protein concentration when compared with the control treatment. Both probiotics presented the lowest values of proteolysis in the treatments with a 30% amplitude—3 min. Lactic, acetic, and citric acids were the organic acids that were present in the highest concentration and formic acid was not detected in either of the two probiotics. It can be concluded that the ultrasound amplitude has a noticeable influence on the growth and fermentation profiles of both probiotics. The results from this study could be used in subsequences investigations to enhance the postbiotic production of Lactobacillus acidophilus and Lactobacillus helveticus.

Effects of High-Intensity Ultrasound Treatments on the Physicochemical and Structural Characteristics of Sodium Caseinate (SC) and the Stability of SC-Coated Oil-in-Water (O/W) Emulsions.

The effects of high-intensity ultrasound treatment (0, 3, 6, 9 min) on physicochemical and structural characteristics of SC and the storage, thermal and freeze–thaw stability of SC O/W emulsions were investigated. The results showed that ultrasound treatment reduced the particle size of SC, although there were no obvious changes in zeta potential, profiles and weights. Ultrasound treatment improved surface hydrophobicity and fluorescence intensity of SC and changed ultraviolet–visible (UV–Vis) spectroscopy but had no influence on the secondary structure of SC. This indicates that ultrasounds might destroy the tertiary structure but leave most of the integral secondary structure. A scanning electron microscope (SEM) also showed that ultrasound-treated SC presented small aggregates and a loose structure. The physicochemical and structural changes of SC benefited the ability of protein adsorbing oil droplets and emulsion stability. Under stresses such as storage, thermal and freeze–thawing, the oil droplets of treated emulsions were still uniform and stable, especially at 6 min and 9 min. Overall, the high-intensity ultrasounds made the SC present small aggregates and a loose structure improving the SC O/W emulsions stability under storage, thermal and freeze–thawing environment and have great potential to stabilize the SC prepared O/W emulsions.

Stability and antimicrobial activity of lemongrass essential oil in nanoemulsions produced by high‐intensity ultrasounds and stabilized by soy lecithin, hydrolyzed whey proteins, gum Arabic, or their ternary admixture

Stability and antimicrobial activity of lemongrass essential oil (LEO) nanoemulsions (NEs) as affected by high-intensity ultrasounds, emulsifier type and concentration were investigated during 14 days of storage. Soy lecithin (SL), whey protein hydrolysates (WPH) and ternary admixture were the most efficient emulsifiers to decrease the droplet size. WPH emulsions, followed by SL, have shown to be the most oxidatively stable with constant levels of PV and TBARS until end of storage, even SL emulsions showed high TBARS levels. Unlike WPH and SL emulsions, gum Arabic (GA) and ternary stabilized admixtures were only able to lag TBARS level up to 7 days of storage. GA emulsions were the most effective as antimicrobials against all pathogens tested. Samples treated with emulsions prepared with GA and WPH, although they were not as efficient in log reduction as the pure oil, the microorganism was not able to recover the survivability after 24 h.

Ultrasounds in cancer therapy: A summary of their use and unexplored potential.

Ultrasounds (US) are a non-ionizing mechanical wave, with less adverse effects than conventional pharmacological or surgical treatments. Different biological effects are induced in tissues and cells by ultrasound actuation depending on acoustic parameters, such as the wave intensity, frequency and treatment dose. This non-ionizing radiation has considerable applications in biomedicine including surgery, medical imaging, physical therapy and cancer therapy. Depending on the wave intensity, US are applied as high-intensity ultrasounds (HIUS) and low-intensity pulsed ultrasounds (LIPUS), with different effects on cells and tissues. HIUS produce thermal and mechanical effects, resulting in a large localized temperature increase, leading to tissue ablation and even tumor necrosis. This can be achieved by focusing low intensity waves emitted from different electrically shifted transducers, known as high-intensity focused ultrasounds (HIFU). LIPUS have been used extensively as a therapeutic, surgical and diagnostic tool, with diverse biological effects observed in tissues and cultured cells. US represent a non-invasive treatment strategy that can be applied to selected areas of the body, with limited adverse effects. In fact, tumor ablation using HIFU has been used as a curative treatment in patients with an early-stage pancreatic tumor and is an effective palliative treatment in patients with advanced stage disease. However, the biological effects, dose standardization, benefit-risk ratio and safety are not fully understood. Thus, it is an emerging field that requires further research in order to reach its full potential.

Low and High-Intensity Ultrasound in Dairy Products: Applications and Effects on Physicochemical and Microbiological Quality.

Milk and dairy products have a major role in human nutrition, as they contribute essential nutrients for child development. The nutritional properties of dairy products are maintained despite applying traditional processing techniques. Nowadays, so-called emerging technologies have also been implemented for food manufacture and preservation purposes. Low- and high-intensity ultrasounds are among these technologies. Low-intensity ultrasounds have been used to determine, analyze and characterize the physical characteristics of foods, while high-intensity ultrasounds are applied to accelerate particular biological, physical and chemical processes during food product handling and transformation. The objective of this review is to explain the phenomenology of ultrasounds and to detail the differences between low and high-intensity ultrasounds, as well as to present the advantages and disadvantages of each one in terms of the processing, quality and preservation of milk and dairy products. Additionally, it reviews the rheological, physicochemical and microbiological applications in dairy products, such as raw milk, cream, yogurt, butter, ice cream and cheese. Finally, it explains some methodologies for the generation of emulsions, homogenates, crystallization, etc. Currently, low and high-intensity ultrasounds are an active field of study, and they might be promising tools in the dairy industry.

Tunable, Functional Carbon Spheres Derived from Rapid Synthesis of Resorcinol-Formaldehyde Resins

In this article, the rapid synthesis of colloidal, spherical polymer resins via enhanced copolymerization and polycondensation of resorcinol with formaldehyde is presented. The ultrasound-mediated technique assembles perfectly spherical resins in less than 5 min due to generated active species and free radicals produced in an aqueous ammonia-ethanol-water solvent. In this report, numerous controlled experiments account for and support the important role of high intensity ultrasounds in the rapid cluster formation, condensation, and gelation process of resorcinol with formaldehyde in the presence of ammonia catalyst. After a controlled heat treatment process, amorphous carbon spheres are obtained from these spherical polymer resins. The effect of temperature (up to 1100 °C) on the structural evolution of these carbon spheres is meticulously studied which is lacking in the previous literature. The resorcinol-formaldehyde resins carbonized at 600 and 900 °C demonstrate BET surface areas of 592.4 m(2)/g and 952.5 m(2)/g with specific capacitances of 17.5, and 33.5 F/g (scan rate of 5 mV/s), respectively.

Application of High-Intensity Ultrasounds to Control the Size of Whey Proteins Particles

In this paper, we reported a new method to prepare whey protein microparticles via high-intensity ultrasound disruption. Particles morphology was characterized by confocal microscopy, and their size and distribution were analyzed by light scattering technique. Starting whey protein isolate (WPI) exhibited changes in size and distribution according to its concentration. For WPI, 7.5% (w/w) mean size was 0.7 µm, and upon sonication at ambient temperature, the size was reduced up to 0.2 µm showing the particles a rounded morphology. Sonication at room temperature of gelled WPI led to particles with sizes between 0.1 and 10 µm which had a tendency to flocculate. When WPI was submitted to sonication under heating at protein denaturation temperature, different effects were observed according to protein concentration. The particle size was reduced for the lowest WPI concentration (7.5 wt.%), did not change at 9 wt.%, but strongly increased at 12 wt.%, in comparison with the untreated sample. WPI particles of desired size in the micron range may be obtained either by sonication of gelled WPI or by sonication under heating at denaturation temperature by controlling processing variables.

Sondes ultrasonores interstitielles mini-invasives pour l’ablation thermique dans le foie : étude de faisabilité in vivo

High Intensity ultrasounds are routinely used for thermal ablation of some cancers. However, for treating hepatic tumours with physical agents, RF applicators and cryoprobes are still preferred. The goal of the present study was to demonstrate the feasibility of using interstitial ultrasound probes in liver following two approaches: percutaneous and intra-tissular or endo vascular. In vivo trials on a porcine model demonstrated the minimally invasive nature of both procedures. Homogeneous and reproducible thermal lesions, up to 20 mm deep, were obtained. The work on these two original approaches deserves to be completed with more extended prospective studies. The association with an imaging method will have to be studied before proceeding to clinical trials.

Dispersion Study of Long and Aligned Multi-Walled Carbon Nanotubes in Water

Dispersion of nanotubes is a crucial step for many applications. The properties of the final nanotube-based material are strongly dependent on the quality of nanotube suspensions. In this study, long and aligned multi-walled carbon nanotubes obtained by catalytic chemical vapour deposition were dispersed in water with different dispersing agents using high intensity ultrasounds. Among different additives, we selected sodium dodecyl sulfate (SDS) as dispersing agent to prepare suspensions of nanotubes. UV-Visible spectrometry method was used to measure the influence of dispersion parameters (power and duration of sonication) on dispersion state and suspension stability. Therefore, we demonstrated that, even if high intensity ultra-sounds are breaking nanotubes, it is possible to obtain stable water-based suspensions containing MWNTs which exhibit length up to 20 microm.

The Reactivity of 4-Hydroxycoumarinunder Heterogeneous High-Intensity Sonochemical Conditions

High-intensity ultrasounds have been employed in the synthesis of 4-hydroxycoumarin derivatives, using mainly water as reaction medium. Marked improvements of reaction rates, chemoselectivity and product yields have been observed on comparing sonochemical with ordinary conditions. In the alkylation of a series of allyl and benzyl bromides a pathway switch occured to yield 3-alkyl-4-hydroxycoumarin derivatives.

Frequency adjustment in high intensity focused ultrasound treatment apparatus

The invention concerns an apparatus for treating a biological sample by emitting focused high intensity ultrasounds towards a focal point, characterised in that it comprises means emitting wideband focused ultrasounds. The apparatus enables to adjust the focused ultrasound frequency according to the target attenuation, the thickness of the tissues traversed, the temperature evolution, or the lesion displacement during emission.

Liposculpture with ultrasound: biomedical considerations.

The authors, after a careful review of the scientific literature and on the basis of biophysical concepts with their own experience, conclude that high-intensity ultrasounds (US) are responsible for some biological lesions, which are partly unknown. US can cause burns and skin necrosis; thus, our employment of this technique must be correct, justified, and practiced very carefully and shrewdly and its advantages versus traditional liposuction must be reviewed.