查看更多>>摘要：In this study, ultrasound application at two different frequencies (37 or 80 kHz) and durations (15 or 30 min) was used as a pre-treatment for raw broiler breasts, and its effect on cooling, color, textural and sensory characteristics of cooked broiler breasts during vacuum cooling process was determined. The anterior and posterior parts of broiler breast halves were carefully removed, and these parts with a 20 mm width were named as the regions A and B, respectively. Both regions were vacuum-packed and pre-treated by ultrasound, followed by oven-cooking in aluminum foils, and cooling time, weight loss and temperature distribution characteristics were determined. Besides sensory and textural properties, the effect of the ultrasound pre-treatment on the pH, dry matter and ash contents and color (CIELAB) values of cooked breasts was determined. During vacuum cooling, ultrasound pre-treatment significantly reduced cooling time required to cool cooked broiler breasts from 85 degrees C to 12.5 degrees C, and the lowest values for the regions A and B were obtained for the 30 min ultrasound pre-treatment at 37 kHz as 12.72 and 14.61 min, respectively (p < 0.05). The cooling losses of breasts from the regions A and B were 12.64 and 11.61%, respectively. In comparison to immersion pre-treatment, increasing the frequency and duration of ultrasound pre-treatment generally decreased cooking loss values for both A and B regions while cooling loss increased. Instrumental hardness values of breast samples for the 15 min ultrasound pre-treatment decreased while they increased with the 30 min pre-treatment (p 0.05) at both frequencies. The redness values (a*) increased by ultrasound pre-treatment while the highest value was found for a 30 min pre-treatment at 80 kHz for both regions. Sensory hardness (on a 14.5 cm scale) results indicated that the highest value (9.33) was determined for a 30 min ultrasound pre-treatment at 37 kHz while the ultrasound pre-treatment at 37 kHz for 15 min had no negative effect on hardness compared to control samples (p 0.05). In conclusion, ultrasound pre-treatment can be successfully used for the vacuum cooling process of broiler breasts for the reduction of cooling time, and a 30 min ultrasound pre-treatment at 37 kHz can provide relatively superior cooling characteristics.
Zhu, XiangluZhang, ZhihangHinds, Laura M.Sun, Da-Wen...
11页
查看更多>>摘要：In this study, ultrasound either as a pretreatment technique or as an integrated technique was employed to enhance fluidized bed drying of Ascophyllum nodosum, and drying kinetics and dried product quality were assessed. In order to compare technology efficiency and dried product qualities, oven drying and fluidized bed drying (FBD) were employed. The novel drying methods included airborne ultrasound-assisted fluidized bed drying (AUA), ultrasound pre-treatment followed by FBD (USP), and hot water blanching pre-treatment followed byFBD (HWB). Six drying kinetics models were used to describe the drying curves, among which the Page model was the best in fitting USP and AUA. Model by Millidi et al. was employed to describe HWB. Airborne ultrasound in AUA did not reduce energy consumption or drying time, but retained total phenolic content (TPC) as well as colour, and exhibited the highest yield among the novel drying methods. USP and HWB showed lower energy consumption and drying time considerably, but the TPC was the lowest among the studied methods. At the same time, USP dried product exhibited the lowest aw, followed by HWB and then AUA. This studyalso demonstrated that FBD could be a very practical drying method on Irish brown seaweed, and ultrasound-assisted drying methods may have potential developments in Irish brown seaweed drying process.
Sadatshojaie, AliWood, David A.Jokar, Seyyed MohammadRahimpour, Mohammad Reza...
12页
查看更多>>摘要：Separating produced water is a key part of production processing for most crude oils. It is required for quality reasons, and to avoid unnecessary transportation costs and prevent pipework corrosion rates caused by soluble salts present in the water. A complicating factor is that water is often present in crude oil in the form of emulsions. Experiments were performed to evaluate the performance of ultrasonic fields in demulsifying crude oil emulsions using novel pipe-form equipment. A horn-type piezoelectric ultrasonic transducer with a frequency of 20 kHz and power ranging from 80 W to 1000 W was used for experimental purposes. The influences of the intensity of ultrasonic fields, ultrasonic irradiation time, and the initial water content of crude oils were evaluated to establish the rate of water segregation from oil. The experiments applied ultrasonic-field intensities of 0.25 W/cm(3), 0.5 W/cm(3), 0.75 W/cm(3) and 1 W/cm(3) to synthetic emulsions with 10%, 15%, 20%, and 25% of the water in crude oil. Crude oil demulsification occurred for each ultrasonic field intensity tested for all the samples tested. Function beta involving adhesion coefficients was expressed in terms of wave-field intensity and initial concentration of water in each of the three crude oil samples tested. The experiments demonstrated that despite the absence of any chemical demulsifier involved, water separation caused by applying ultrasonic fields was effective and occurred rapidly. As the intensity of the ultrasonic field applied increased, the amount of water segregated from crude oil also increased. Subjected to constant field intensity, higher initial water cuts (up to 15% or so) in the crude oil samples and higher ultrasonic irradiation times, resulted in greater segregation of water from crude oil in percentage terms. However, in samples with initial water cuts of 20+% long irradiation times (similar to 5 min), resulted in a decline in water separation compared to 2-min tests. Ultrasonic field treatments offer commercially-viable and environmentally-friendly alternatives to treatments using chemical demulsifiers as they reduce desalination requirements of wastewater.
查看更多>>摘要：In this work, the effects of high power ultrasound treatment (40 kHz) on virgin olive oil (VOO) for different times (0, 15, 30 min) were studied, in order to verify if extent modifications in their chemical composition and thermal properties. The effects of the different ultrasound treatments on VOOs were determined considering the following parameters: quality index (free acidity, K-232 and K-270), lipid profile (fatty acids and triglycerides composition) minor components (phenols, tocopherols, pigments and volatiles) and thermal properties (crystallization and melting) by Differential Scanning Calorimetry (DSC).
查看更多>>摘要：The use of deep eutectic solvents (DESs) as a new extraction medium is a step towards the development of green and sustainable technology. In the present study, nine DESs based on choline chloride acids, alcohols, and sugar were screened to study the extraction of curcuminoids from Curcuma longa L. Choline chloride and lactic acid DES at 1:1 M ratio gave the maximum extent of extraction. Further, DES based extraction was intensified using ultrasound. The impact of various process parameters such as % (v/v) water in DES, % (w/v) solid loading, particle size, ultrasound power intensity, and pulse mode operation of ultrasound was studied. The maximum curcuminoids yield of 77.13 mg/g was achieved using ultrasound assisted DES (UA-DES) based extraction in 20% water content DES at 5% solid loading and 0.355 mm particle size with 70.8 W/cm(2) power intensity and 60% (6 sec ON and 4 sec OFF) duty cycle at 30 +/- 2 degrees C in 20 min of irradiation time. Kinetics of UA-DES extraction was explained using Peleg's model and concluded that it is compatible with the experimental data. Additionally, anti-solvent (water) precipitation technique was applied, which resulted in 41.97% recovery of curcuminoids with 82.22% purity from UA-DES extract in 8 h of incubation at 0 degrees C. The comparison was made between conventional Soxhlet, batch, DES and UA-DES based processes on the basis of yield, time, solvent requirement, temperature, energy consumption, and process cost. The developed UA-DES based extraction can be an efficient, cost effective, and green alternative to conventional solvent extraction for curcuminoids.
查看更多>>摘要：In the present work, chitin suspensions after enzymolysis and sonoenzymolysis were taken as adsorbents to evaluate the adsorption properties of Congo red (CR) dyes. Compared with untreated chitin suspension, the CR adsorption performance was significantly improved after enzymolysis and even more after sonoenzymolysis. According to different adsorption kinetic and isotherm models, Langmuir isotherm and the pseudo-second order model were more reliable to describe the adsorption process of CR onto different chitin samples and demonstrated a monolayer and favorable physisorption process. What's more, negative values of Delta G (Gibbs free energy change) and the shifts to higher negative values with the temperature increasing from adsorption thermodynamic study proved a spontaneous CR adsorption process. The structural characterization before and after adsorption further verified the physical adsorption between chitin and CR, and a larger specific area and higher porosity of chitin suspension was obtained after sonoenzymolysis with more available active sites.
查看更多>>摘要：The present work consists of an innovative approach aiming to address the scalability dilemma of the sonochemical activity dependency of acoustic frequency. The study originates from the discordance of observations between the theoretical investigations of the sonochemical activity of the single acoustic cavitation bubble in function of the acoustic frequency, in one hand, and the experimental findings regarding the optimal frequency condition, mainly in terms of pollutant degradation, in the other hand. A single bubble and an up-scaled model of the sonochemical activity are suggested and simulations were conducted based on both of them over the frequencies 20, 200, 300, 360, 443, 500, 600 and 800 kHz under an oxygen atmosphere. The results reveal that the sonochemical production at single bubble scale is monotonously decreasing with the increase of frequency, while all the products demonstrate an absolute optimum of sonochemical production at 200 kHz, except HO center dot that attains its maximum molar yield under 300 kHz. Besides, the production of the predominant species, namely HO2 center dot, HO center dot and O-3, manifests a clear rebound at 500 kHz. All the present results were compared to and confirmed by experimental findings, while the scalability of the concentrations of sonochemically produced species was discussed using a parameter we introduced as "the mass focusing factor".
查看更多>>摘要：Ultrasound was combined with ethanol to improve different aspects of carrot convective drying, evaluating both processing and product quality. The ultrasound in water treatment resulted in cellular swelling and small impact on texture. Differently, the ultrasound in ethanol and ethanol treatments modified both carrot microstructure (cell wall modifications of parenchymatic tissue) and macrostructure (shrinkage and resistance to perforation). Pre-treatments with ultrasound in ethanol and ethanol improved the drying kinetics, reducing the processing time (similar to 50%) and the energy consumption (42-62%). These pre-treatments also enhanced rehydration, whose initial rate and water retention were higher than the control. In addition, the carotenoid content was preserved after drying, for all the treatments. Any impact on shrinkage was observed. A mechanistic discussion, based on structural modification (microstructure and macrostructure) and physical properties of water and ethanol, was provided. As conclusion, this work not only described positive aspects of combining the technologies of ultra sound and ethanol as pre-treatments to convective drying, but also proposed mechanisms to explain the phenomena.
查看更多>>摘要：Surimi from silver carp with different salt contents (0-5%) was obtained treated by high intensity ultrasound (HIU, 100 kHz 91 W.cm(-2)). The gelation properties of samples were evaluated by puncture properties, microstructures, water-holding capacity, dynamic rheological properties and intermolecular interactions. As the salt content increased from 0 to 5%, gel properties of surimi without HIU significantly improved. For samples with low-salt (0-2% NaCl) content, HIU induced obvious enhancement in breaking force and deformation. HIU promoted the protein aggregation linked by SeS bonds, hydrophobic interactions and non-disulfide covalent bonds in surimi gels with low-salt content. Moreover, microstructures of HIU surimi gels with low-salt content were more compact than those of the corresponding control samples. HIU also improved the gelation properties of surimi with 3% NaCl to an extent. However, for high-salt (4-5% NaCl) samples, HIU decreased the breaking force and deformation of surimi gels due to the degradation of proteins suggested by increased TCA-soluble peptides. In conclusion, HIU effectively improved the gelation properties of surimi with low-salt content (0-2% NaCl), but was harmful for high-salt (4-5% NaCl) surimi. This might provide the theoretical basis for the production of low-salt surimi gels.
Fuentes-Garcia, J. A.Santoyo-Salzar, J.Rangel-Cortes, E.Goya, G. F....
8页
查看更多>>摘要：In this work, optimized size distribution and optical properties in the colloidal synthesis of gold nanoparticles (GNPs) were obtained using a proposed ultrasonic irradiation assisted Turkevich-Frens method. The effect of three nominal ultrasound (20 kHz) irradiation powers: 60, 150, and 210 W have been analyzed as size and shape control parameters. The GNPs colloidal solutions were obtained from chloroauric acid (HAuCl4) and trisodium citrate (C(6)H(5)Na(3)O(7)2H(2)O) under continuous irradiation for 1 h without any additional heat or stirring. The surface plasmon resonance (SPR) was monitored in the UV-Vis spectra every 10 min to found the optimal time for localized SPR wavelength (ALSPR), and the 210 sample procedure has reduced the ALSPR localization at 20 min, while 150 and 60 samples have showed ALSPRat 60 min. The nucleation and growth of GNPs showed changes in shape and size distribution associated with physical (cavitation, temperature) and chemical (radical generation, pH) conditions in the aqueous solution. The results showed quasi-spherical GNPs as pentakis dodecahedron (ALSPR = 560 nm), triakis icosahedron (ALSPR = 535 nm), and tetrakis hexahedron (ALSPR = 525 nm) in a size range from 12 to 16 nm. Chemical effects of ultrasound irradiation were suggested in the disproportionation process, electrons of AuCl2- are rapidly exchanged through the gold surface. After AuCl4- and Cl- were desorbed, a tetrachloroaurate complex was recycled for the two-electron reduction by citrate, aurophilic interaction between complexes AuCl2-, electrons exchange, and gold seeds, the deposition of new gold atoms on the surface promoting the growth of GNPs. These mechanisms are enhanced by the effects of ultrasound, such as cavitation and transmitted energy into the solution. These results show that the plasmonic response from the reported GNPs can be tuned using a simple methodology with minimum infrastructure requirements. Moreover, the production method could be easily scalable to meet industrial manufacturing needs.
NSTL
Elsevier