Ultrasound Powers Research Articles

Effect of ultrasound power on moisture status change of apple by contact ultrasound reinforced far-infrared radiation drying

To explore the effect of ultrasound power on internal water change of apple dried by contact ultrasound enhanced far-infrared radiation drying (CUFRD), the drying characteristics, microstructure, moisture migration, and molecular vibration patterns of apple slices subjected to this process at different ultrasound powers were investigated using low-field nuclear magnetic resonance (LF-NMR), Near-infrared (NIR) and two-dimensional(2D) correlation analysis. With the increase of contact ultrasound (CU) power, the drying times of apple were shortened by 8.69% to 17.39%, respectively. Scanning electron microscopy (SEM) observation indicated that higher CU power resulted in an increase in the number of microporous channels and pore diameter within apple’s internal tissue. The findings of LF-NMR clarified that free water content kept decreasing, while the content of semi-bound water initially increased and then reduced. Magnetic resonance imaging (MRI) images illustrated that higher CU power corresponded to a faster decrease in the redness value of the H+ density map of apple during drying. 2D correlation analysis revealed that the changes in the O-H bonds of apple were prioritized over the C-H bonds during drying process. NIR spectroscopy and LF-NMR heterogeneous correlation spectrograms demonstrated that at wavelengths of 950, 1450, and 1680 nm, the order of changes in water-related functional groups was quadruple-frequency O-H > combination of the first overtone of O-H stretching and OH-bending band > double-frequency C-H. Moreover, with increasing CU power, the vibration of hydrogen-containing functional groups intensified, leading to increased water activity. Thus, CU application could significantly enhance the CUFRD process of apple slices.

Low‐intensity continuous ultrasound effect on proliferation and morphology of fibroblast cells

AbstractRecently, the use of ultrasound (US) for triggering drug release to specific tissues was explored, but its direct effects on cells have not been thoroughly understood. For this reason, this study aimed to investigate the impact of US powers and US irradiation times on fibroblast cells (NIH‐3T3). The results showed that the diverse US settings had varying effects on cell proliferation and distribution in the polystyrene culture dish. Interestingly, at 10 W, 43 kHz with changing exposed time up to 30 min either stimulated or inhibited fibroblast cell growth after 24 and 72 h of cultivation compared to the control sample in the absence of US, while longer US exposure time led to a moderate reduction in cell quantity. Moreover, higher US levels of 20 and 30 W could cause an aggregation of cells and sublethal damage to the cells. Importantly, the morphology of fibroblast was changed from stellate‐shape to round‐shape under greater US powers. Elevated US power also influenced interactions between proteins and lipids, affecting the atomic and molecular charges, leading to changes in both zeta potential and pH of the dispensed cell solution.

Effect of Ultrasonic Treatment on the Physicochemical Properties of Bovine Plasma Protein-Carboxymethyl Cellulose Composite Gel.

In order to improve the stability of bovine plasma protein-carboxymethyl cellulose composite gels and to expand the utilization of animal by-product resources, this study investigated the impact of different ultrasound powers (300, 400, 500, 600, and 700 W) and ultrasound times (0, 10, 20, 30, and 40 min) on the functional properties, secondary structure and intermolecular forces of bovine plasma protein-carboxymethyl cellulose composite gel. The results showed that moderate ultrasonication resulted in the enhancement of gel strength, water holding capacity and thermal stability of the composite gels, the disruption of hydrogen bonding and hydrophobic interactions between gel molecules, the alteration and unfolding of the internal structure of the gels, and the stabilization of the dispersion state by electrostatic repulsive forces between the protein particles. The content of α-helices, β-turns, and β-sheets increased and the content of random curls decreased after sonication (p < 0.05). In summary, appropriate ultrasound power and time can significantly improve the functional and structural properties of composite gels. It was found that controlling the thermal aggregation behavior of composite gels by adjusting the ultrasonic power and time is an effective strategy to enable the optimization of composite gel texture and water retention properties.

Ultrasound thawing for improving the eating quality and off-flavor of frozen duck meat and its possible mechanisms

The aim of this study was to investigate the effect of ultrasound thawing on the eating quality and off-flavor of frozen duck meat and discuss its possible mechanisms. The thawing rate, meat quality, Low-field nuclear magnetic resonance (LF-NMR), secondary structure, free amino acid (FAA) and volatile flavor compounds under different ultrasound thawing power (0, 200, 400, and 600 W) were determined. The results showed that ultrasound powers ranging from 200 W to 600 W significantly shortened the thawing time by 30.96%–55.05%. Compared to the control group without ultrasound treatment, 400 W ultrasound thawing significantly reduced (P < 0.05) thawing loss, pH, L*, b*, shear force and pressure water loss, and increased a*, ΔE, and BI, indicating an improvement in color, tenderness, and water holding capacity (WHC). LF-NMR and Raman spectra analyses demonstrated that 400 W ultrasound thawing effectively reduced the loss of free water and promoted the α-helix to β-sheet transition, thereby improving the WHC. Moreover, the off-flavor compounds of duck meat were effectively reduced by inhibiting lipid oxidation and FAA degradation in 400 W ultrasound thawing group. These findings provide a new perspective on the reduction of off-flavor and optimizing ultrasound thawing power of frozen duck meat.

Effect of high-intensity ultrasonic treatment on the physicochemical, structural, rheological, behavioral, and foaming properties of pumpkin (Cucurbita moschata Duch.)-seed protein isolates

Pumpkin-seed protein isolates were treated with high-intensity ultrasound (HIU). The effects of different ultrasound powers at the same treating time on the physicochemical, structure and foaming properties of pumpkin-seed protein isolates (PSPIs) were investigated. The results showed that the ultrasound treatment transformed the PSPI aggregates into smaller aggregates with a more uniform distribution. When the pH value increased, the solubility and foaming ability of the protein also increased significantly. Increasing the ultrasound power also increased the surface hydrophobicity of the PSPIs and the total sulfhydryl contents, while the active sulfhydryl content decreased. The most significant effect on the total sulfhydryl content occurred when 500 W ultrasonic power was used. The ultrasound treatment also had a significant effect on the chromaticity and turbidity of the pumpkin-seed protein isolates. With an increase in ultrasonic power, scanning electron microscopy (SEM) showed that the sizes of particles decreased as their distribution increased. Moreover, ultrasound treatment was found to be beneficial for enhancing and improving foaming performance. Ultrasound modification affected the protein's physicochemical properties and structure, which contributed greatly to the corresponding functional and nutritional properties of the protein. It would be, therefore, useful to develop and utilize plant protein and to improve its added-value.

Ultrasound-triggered nicotine release from nicotine-loaded cellulose hydrogel

Ultrasound (US)-triggered nicotine release system in a cellulose hydrogel drug carrier was developed with three different cellulose concentrations of 0.45 wt%, 0.9 wt%, and 1.8 wt%. The nicotine-loaded cellulose hydrogels were fabricated by the phase inversion method when the nicotine and cellulose mixture in the 6 wt% LiCl/N, N-dimethylacetamide solvent was exposed to water vapor at room temperature. Nicotine was used as the medicine due to its revealed therapeutic potential for neurodegenerative diseases like Alzheimer's and Parkinson's diseases. The behavior of US-triggered nicotine release from nicotine-cellulose hydrogel was studied at 43 kHz US frequency at the changing US output powers of 0 W, 5 W, 10 W, 20 W, 30 W, and 40 W. The significant US-triggered nicotine release enhancement was noted for the hydrogels made with 0.9 wt% and 1.8 wt% cellulose loading. The matrix made with 0.9 wt% cellulose was exhibited the highest nicotine release at the 40 W US power, and differences in nicotine release at different US powers were noticeable than at 0.45 wt% and 1.8 wt% cellulose loadings. For the three cellulose hydrogel systems, the storage modulus (G′) values at the 0.01 wt% strain rate were dropped from their initial values due to the US irradiation. This reduction was proportionately decreased when the US power was increased. The deconvolution of FTIR spectra of nicotine-loaded cellulose films before and after US exposure was suggested breakage of cellulose-nicotine and cellulose-water in the matrix; thus, the stimulated nicotine release from the cellulose matrix was promoted by the US irradiation.

Effects of different ultrasound powers on the structure and stability of protein from sea cucumber gonad

The effects of ultrasound with different powers (0-500 W) on the structure and stability of protein from sea cucumber gonad were investigated, according to the changes in phenylalanine (Phe), α-helix, β-sheet, tryptophan (Trp), surface hydrophobicity, particle size distribution, microstructure and amino acid (AA). With the increase in ultrasound power, the contents of Phe, β-sheet and Trp, surface hydrophobicity and particle size first increased and then decreased, while α-helix content was opposite. Compared with the non-ultrasound group, the content of α-helix and random coil significantly decreased by 24.71% and 22.33% in the 200 W ultrasound group, while Phe content, β-sheet content, fluorescence intensity (FI), the surface hydrophobicity and hydrophobic AA significantly increased by 12.77%, 75.91%, 7.90%, 15.61% and 7.00%, respectively (P < 0.05). According to microstructure analysis, after 200 W ultrasound treatment, the protein particles became smaller and more uniform, and the protein structure was much looser than that without ultrasound treatment. Overall, the side chain, secondary, and tertiary structure of protein from sea cucumber gonad were unfolded under ultrasound treatment, which exposed more hydrophobic groups and decreased protein aggregation, and the effect of ultrasound with 200 W on the protein structure was prominent.

Investigation of the Synergistic Effect of Sonolysis and Photocatalysis of Titanium Dioxide for Organic Dye Degradation

Herein, we report the effect of sonoluminescence and an initial dye concentration on the sonophotocatalysis of TiO2 for the degradation of eosin B, a textile dye. We first investigated the light illuminated during ultrasound irradiation (sonoluminescence) by photographic images, a radical indicator (luminol), and photoluminescence spectra of the detection range of 300–1050 nm. Next, we examined the synergistic effect of sonolysis on photocatalysis by comparing the dye degradation of sonophotocatalysis to that of individual contributions of sonolysis and photocatalysis. Since it was found that the synergist effect is highly engaged with a dye concentration and sonication power, we conducted the comparison test in different concentrations of eosin B (5 and 20 mg/L) and ultrasound powers (35.4, 106.1, and 176.8 W/cm2). When the concentration of dyes was low, negative synergistic effects were found at all ultrasound powers, whereas at the high concentration, positive synergistic effects were observed at high ultrasound power. This difference in synergistic effects was explained by the influence of ultrasound on dynamics of dye adsorption on the TiO2 surface.

Assessment of corneal endothelial status post phacoemulsification with 1% ultrasound power in hard cataracts

Purpose: This study was conducted to discover that whether Co-axial micro incision cataract surgery using 1% ultrasound is superior to phacoemulsification using higher powers in terms of corneal endothelial safety over a period of one year. Materials and Methods: This comparative randomized study was conducted from 11-01-2014 to 03-31-2016. Patients with hard cataracts [5.0-6.9 of lens opacities classification system-III] were randomized into four groups and underwent cataract surgery using ultrasound powers of 1%, 5%, 10% and 20% respectively. Post-operatively they were assessed in terms of- corneal endothelial cell loss, co-efficient of variation of cell size, percentage of hexagonal cells and corneal thickness. The other parameters that were investigated were - frequency of significant posterior capsular opacification, best corrected visual acuity and Intraocular pressure variations. Results: This study found that application of 1% ultrasound power is superior to 5%, 10% or 20% power in phacoemulsification cataract surgery in terms of quantitative endothelial cell analysis (endothelial cell density, percentage of loss of endothelial cells, coefficient of variation, central corneal thickness and percentage of hexagonal cells) over one year follow up post-operatively. On comparison all parameters were found to be statistically significant when compared to the application of 20% power. Conclusion: Negative effects of ultrasound power (used in phacoemulsification) on corneal endothelial health have been well documented in the literature. We found that minimizing this power to 1% is effective in maintaining corneal endothelial viability without compromising the surgical experience and post-operative visual outcome. Keywords: 1% Ultrasound power, Coefficient of variation, Endothelial cell density, Percentage hexagonal cells, Phacoemulsification.

Influence of ultrasound frequency and power on lactose nucleation

This work was aimed at studying the effect of different ultrasound frequencies (20, 44, 98, 142 kHz) and ultrasound powers (10, 20, 30 W) on lactose nucleation. For this purpose, lactose solutions (25% w/v) with traces of whey proteins (0.3%) were sonicated 300 s. Crystallization was induced by reducing the temperature from 30 to 15 °C, which increased the absolute supersaturation of lactose (Cα-Cαs) from 0.19 to 8.25 g 100 g−1. The nucleation of lactose was monitored by light scattering. Results showed that application of ultrasound (US) modified both, the molecular-attachment frequency to form new nuclei (k) and the induction time. The ultrasound effect on lactose nucleation varied depending on the US-frequency or power applied. The most noticeable changes were observed at 44 kHz (11.13 J mL−1) since the number of nuclei formed (a) raised, the k-value increased to 0.1482 s−1, and the induction time decreased to 15 s.

IMPROVEMENT IN SOYBEAN SPROUTS PRODUCTION WITH ULTRASOUND POWER

The present work aimed the application of different ultrasound powers (10, 50 and 90W) to evaluate the germination and characteristics of soybean sprouts fromsoybeans of cultivar BRS 216 and 3 lines (A, B and C). In the germination test,the line A showed the highest percentage of germination (96% for 90W).The cultivar BRS 216 and line A present lower values of weight and higher yield of sprouts. The viable sprouts that presented the highest weight (for each 50g of soybean) were: line A followed by BRS 216, line C and B, with statistical differences (p&lt;0.05) between them. For each 50g of soybean of cultivar BRS 216 and Lines A, B and C the production of viable sprouts was 231.47; 237.87; 170.74 and 199.94g, respectively, for 90W. In relation to the length of the sprouts using the power of 10W the line C presented a longer length. The line A using 90W showed better color characteristics. The highest protein value was found in cultivar BRS 216, for all applied potencies. With this work it can be concluded that the line A would be the most suitable for sprout production regardless of the ultrasound power applied

The effect of combined AC electric field and ultrasound on the chemical compositions and Escherichia coli content of spearmint aromatic water

AbstractThe aromatic waters are one of the forms of the use of medicinal plants, mostly for edible or medicinal uses. They are required to control the microbial load. Common methods of pasteurization by reason of applying high temperatures cause the undesirable changes in taste, odor, medicinal properties, nutritional quality, and reduction in essential oil. Therefore, novel methods of pasteurization have been widely used recently. In order to determine the microbial inactivation by pulsed electric field and ultrasound, Escherichia coli at a concentration of 7 × 106/mL was inoculated to spearmint aromatic water. The field intensities of 5, 7.5, and 10 kV/cm with time durations of 5, 20, and 35 s and ultrasound powers of 100, 150, and 200 W with time durations of 3, 4, and 5 min were applied. The data obtained from the experiments were analyzed using response surface methods. The results showed that the effect of the four variables listed on the inactivation of microorganisms and energy consumption per cycle of microbial reduction are significant. At the end, the process was optimized. The optimum values for the electric field intensity, time of applying the field, the ultrasound power, and sonication time were 10 kV/cm, 35 μs, 185.90 W, and 4.47 min, respectively. It should be noted that the proposed method had minimal changes in the chemical composition of the raw spearmint aromatic water and was superior to conventional heating methods.Practical applicationsThe mint aromatic water is used in food, pharmaceutical, and personal care industries; it is necessary to microbiological control of its content. Because of conventional pasteurization methods cause undesirable changes in taste, smell, and nutritional quality with a reduction in the amount of essential oil. For this purpose, researchers are looking for solutions that by combining new thermal and nonthermal approaches, the damaging effects of conventional pasteurization be removed. However, the main challenge facing the nonthermal technologies in food processing is the inactivation of pathogenic microorganisms and food spoilage agents, which can be achieved by various methods. The aim of the present research was examined the simultaneous effect of the ultrasonic and the electric field to remove microorganism and save quality and benefit chemical compositions of medicinal aromatic water. This research introduces an innovative and combined method for aromatic water pasteurization and this method can benefit to the food industry.

Influence of ultrasound-assisted immersion freezing on the freezing rate and quality of porcine longissimus muscles

The objective of this study was to evaluate the effect of ultrasound-assisted immersion freezing (UIF) on the freezing rate and quality of porcine longissimus muscles under different ultrasound powers. UIF with a certain level of ultrasound power significantly (P>0.05) accelerated the freezing rate. The phase transition times of samples treated with UIF at 180W (UIF-180) were the shortest. There were no significant differences (P>0.05) in a* (redness), b* (yellowness), pH values or cooking loss among UIF, IF, and control (fresh muscle) samples. Investigation of the microstructure of frozen muscles demonstrated that UIF-180 remarkably reduced the size of ice crystals and made their distribution more uniform. UIF-180 samples showed a significant (P<0.05) reduction in thawing loss and T21 and T22 relaxation times compared with other treatments, which meant that UIF at certain powers could reduce the mobility and loss of immobilized and free water. The results showed that UIF at certain powers significantly increased the freezing rate of muscle samples and improved meat quality.

Ultrasound-assisted extraction of fructans from agave (Agave tequilana Weber var. azul) at different ultrasound powers and solid-liquid ratios

The effects of ultrasound-assisted extraction (UAE) at different ultrasound power densities (UPDs; 40, 80, and 120 mW/mL) and solid:liquid (S:L) ratio (1:2, 1:3, and 1:6) on the extraction of carbohydrates from Agave tequilana plant of different ages were evaluated. Extracts obtained (6- and 7-year-old plant) were analyzed in the yield of carbohydrates (YC), fructan (FRU) content, simple sugars, fructan profile and the average degree of polymerization (DPn). UPD, S:L ratio, and plant age all affected YC, FRU, and DPn. Maximum YC and FRU were obtained from the older agave with UPD and S:L ratio of 120 mW/mL and 1:6, respectively; while glucose, fructose, and sucrose were highly released from the younger plant. Agave of 7-year-old presented the highest DPn. Fructan degradation occurred at high UPD, increasing the simple sugars and decreasing the DPn. Thermal-traditional extraction without sonication caused more fructan degradation; and overall, ultrasound enhanced fructan extraction and minimized fructan damage, representing a technological alternative for fructan extraction from agave.

Ultrasound stimulated release of gallic acid from chitin hydrogel matrix

Ultrasound (US) stimulated drug release was examined in this study using a chitin hydrogel matrix loaded with gallic acid (GA), a drug used for wound healing and anticancer. Using phase inversion, GA-chitin hydrogels were prepared from chitin-dimethylacetamide (DMAc)/lithium chloride (LiCl) solution in the presence of GA, with 24h exposure of the solution to water vapor. The GA release from the GA-chitin hydrogel was examined under different US powers of 0–30W at 43kHz. The effects of GA loading amounts in the hydrogels (0.54, 0.43, and 0.25mg/cm3) and chitin concentrations (0.1, 0.5, and 1wt%) on the release behaviors were recorded under 43kHz US exposure at 30W. Results show that US accelerated the release efficiencies for all samples. Furthermore, the release efficiency increased concomitantly with increasing US power, GA loading amount, and decrease of the chitin concentration. The highest release rate of 0.74μg/mL·min was obtained from 0.54mg/cm3 of GA-loaded hydrogel fabricated from a 0.1wt% chitin mixture solution under 43kHz US exposure at 30W: nine times higher than that of the sample without US exposure. The hydrogel viscoelasticity demonstrated that the US irradiation rigidified the material. FT-IR showed that US can break the hydrogen bonds in the GA-chitin hydrogels.

Hot air drying of purple-fleshed sweet potato with contact ultrasound assistance

ABSTRACTA drying technique using a combination of a contact ultrasound apparatus and a hot air dryer is developed to investigate the strengthening effect of contact ultrasound on hot air drying. The effects of drying parameters such as ultrasound power and drying temperature on drying characteristics, effective moisture diffusivity (Deff), microstructure, glass transition temperature (Tg), rehydration ratio, and color difference are discussed. The results show that the application of contact ultrasound causes a significant acceleration of internal mass transfer, and higher ultrasound power applied leads to faster drying rate. The effect of ultrasound power on drying rate decreases along with the reduction of moisture content during drying process. The increase in drying temperature significantly reduces drying time but has a little negative influence on the strengthening effect of ultrasound. Deff values range from 1.0578 × 10−10 to 5.4713 × 10−10 m2/s in contact ultrasound-assisted hot air drying of purple-fleshed sweet potato and increase significantly with an increase in drying temperature as well as ultrasound power. The microstructure of purple-fleshed sweet potato is greatly different at different ultrasound powers during contact ultrasound-assisted hot air drying and shows more microchannels and dilated intercellular spaces in the cross-section of purple-fleshed sweet potato micrographs at higher ultrasound power. Contact ultrasound application during hot air drying could improve the mobility of water and consequently reduce glass transition temperature. Lower color difference and higher rehydration ratio could be achieved as drying temperature decreases and ultrasound power increases. The increase in contact ultrasound power could reduce energy consumption of drying process up to 34.60%. Therefore, contact ultrasound assistance is a promising method to enhance hot air drying process.

Ultrasound stimulated release of mimosa medicine from cellulose hydrogel matrix

Ultrasound (US) drug release system using cellulose based hydrogel films was developed as triggered to mimosa. Here, the mimosa, a fascinating drug to cure injured skin, was employed as the loading drug in cellulose hydrogel films prepared with phase inversion method. The mimosa hydrogels were fabricated from dimethylacetamide (DMAc)/LiCl solution in the presence of mimosa, when the solution was exposed to ethanol vapor. The US triggered release of the mimosa from the hydrogel matrix was carried out under following conditions of US powers (0–30W) and frequencies (23, 43 and 96kHz) for different mimosa hydrogel matrix from 0.5wt% to 2wt% cellulose solution. To release the drug by US trigger from the matrix, the better medicine release was observed in the matrix prepared from the 0.5wt% cellulose solution when the 43kHz US was exposed to the aqueous solution with the hydrogel matrix. The release efficiency increased with the increase of the US power from 5 to 30W at 43kHz. Viscoelasticity of the hydrogel matrix showed that the hydrogel became somewhat rigid after the US exposure. FT-IR analysis of the mimosa hydrogel matrixes showed that during the US exposure, hydrogen bonds in the structure of mimosa–water and mimosa–cellulose were broken. This suggested that the enhancement of the mimosa release was caused by the US exposure.

Evaluation of the sonosensitizing properties of nano-graphene oxide in comparison with iron oxide and gold nanoparticles

In cancer hyperthermia, ultrasound is considered as an appropriate source of energy to achieve desired therapeutic levels of heating. It is assumed that such a heating is targeted to cancer cells by using nanoparticles as sonosensitization agents. Here, we report the sonosensitizing effects of Nano-Graphene Oxide (NGO) and compare them with gold nanoparticles (AuNPs), Iron Oxide nanoparticles (IONPs).Experiments were conducted to explore the effects of nanoparticle type and concentration, as well as ultrasound power, on transient heating up of the solutions exposed by 1MHz ultrasound. Nanoparticles concentration was selected from 0.25 to 2.5mg/ml and the solutions were exposed by ultrasound powers from 1 to 8W. Real time temperature monitoring was done by a thermocouple and obtained data was analyzed.Temperature profiles of various nanoparticle solutions showed the higher heating rates, in comparison to water. Heating rise was strongly depended on nanoparticles concentration and ultrasound power. AuNPs showed a superior efficiency in heat generation enhancement in comparison to IONPs and NGO.Our result supports the idea of sonosensitizing capabilities of AuNPs, IONPs, and NGO. Targeted hyperthermia may be achievable by preferential loading of tumor with nanoparticles and subsequent ultrasound irradiation.

In situ Raman quantification of the dissolution kinetics of carbon dioxide in liquid solutions during a dense phase and ultrasound treatment for the inactivation of Saccharomyces cerevisiae

In this work, a Raman based optical approach is presented that enables remote, real time and in situ quantification of the amount of carbon dioxide (CO2) dissolved in distilled water and coconut water during a dense phase carbon dioxide (DPCD) and a combined dense phase carbon dioxide and ultrasound (DPCD+US) pasteurization.CO2 dissolution kinetics were measured in an optically accessible high pressure cell at different temperatures (25, 35, 40°C) and pressures (8 and 12MPa). Two different mixing devices (mechanical and magnetic) during DPCD treatment, and different ultrasound powers (10, 20, 30W) during the DPCD+US treatment were applied. The dissolution data were then related with the inactivation ratio of Saccharomyces cerevisiae inoculated into the solutions. The results demonstrated that an increase of pressure or time during DPCD treatment enhances the amount of CO2 dissolved into the liquid, leading to a higher inactivation degree; the same trend was observed when the temperature was increased, although in this latter case, the amount of dissolved CO2 decreased. The increase of pressure during a combined DPCD+US treatment led to a higher amount of dissolved CO2, which positively influenced the microbial inactivation while no effect was obtained increasing the ultrasound power. Concerning the effect of the mixing devices, the mechanical stirrer was the one that enhanced the pasteurization efficiency as it influenced CO2 dissolution kinetics and, consequently, the microbial inactivation ratio. The composition of the liquid solutions also influenced the amount of dissolved CO2 but no correlations were found with S. cerevisiae inactivation.

Effect of ultrasound power on physicochemical and rheological properties of yoghurt drink produced with thermosonicated milk

The aim of the study was to determine the effect of ultrasound power on some selected quality parameters of yogurt drink produced with thermosonicated milk. Ultrasonication treatments for raw milk samples preheated to 70C were carried out at different ultrasound powers (100, 125 and 150W). Yogurt drinks were produced with milk samples processed with thermosonication or conventional heating (10 min at 90C). Thermosonication treatment did not influence proximate composition and color properties of samples; however, it decreased serum separation values significantly while increasing apparent viscosity values at higher ultrasound power. Rheological measurements indicated that all yogurt drink samples exhibited a non-Newtonian behavior. In conclusion, thermosonication treatment could be successfully used in the production of yoghurt drink and improve its major quality parameters such as delayed serum separation and increased apparent viscosity.