The effect of ultrasound on enzymatic degumming process of rapeseed oil by the use of phospholipase A1

Comparative studies of enzymatic degumming process of rapeseed oil were carried out in mechanical-stirring and ultrasonic-assisted mechanical-stirring systems. The influences of enzyme dosage (10–50 mg/kg), pH (4.5–6), temperature (45–65 °C), water amount (1–3%), ultrasonic power (0.06–0.09 W/cm³) and reaction time were investigated subsequently. A suitable ultrasonic power of 0.07 W/cm³ was determined to guarantee satisfactory degumming efficiency and enzyme activity. Compared to the mechanical-stirring system, optimum temperature of phospholipase A (PLA) in the ultrasonic-assisted mechanical-stirring system was about 5 °C higher, while the effects of pH on both of the two systems were quite similar. Less time and water were used in the ultrasonic-assisted mechanical-stirring system for enzymatic degumming. The study on the quality changes of degummed oils showed that ultrasound could accelerate the oxidation of edible oils due to the effect of cavitation, thus more attention should be paid on the oxidative stability in the further application.     

Ultrasound assisted enzymatic degumming of crude soybean oil

The present work deals with ultrasound assisted enzymatic degumming (UAED) of crude soybean oil quantifying the extent of degumming (EOD), cavitational yield and synergistic index (f) for the combination approaches. The effect of different operating parameters such as enzyme loading, pH, presence of water, temperature and ultrasonic power on the EOD has been investigated. Ultrasound combined with enzyme at loading of 2.0 ml/L resulted in EOD as 92.2% under ambient conditions. Addition of water (5%) in combination with ultrasound and enzyme at 2.0 ml/L loading and pH of 5 resulted in maximum EOD (98.4%) in 120 min of treatment. The extent of phospholipid separation was also observed to be dependent on the power dissipation and maximum phospholipids separation was obtained at 100 W. Scale-up studies were performed at 500 ml and 1 L operating volume under optimized conditions of 2.0 ml/L as the enzyme loading, pH of 5, 5% water addition and ultrasonic power of 100 W where 93.63% and 91.15% phospholipid separation respectively was obtained. The effects of ultrasonic treatment were also quantified in terms of the acid value reduction and oxidative stability for the processed oil. It was demonstrated that suitable reduction in acid value (final value less than 1) and oxidative stability (TOTOX less than 4) is effectively obtained using UAED. Overall the approach of UAED was established to show much higher efficacy for soybean oil processing as compared to only ultrasound or only enzymatic treatment.     

Effect of ultrasound on the structural characteristics and oxidative stability of walnut oil oleogel coated with soy protein isolate-phosphatidylserine

In this study, the three-dimensional network system formed by rice bran wax (RBW) was used as the internal structure, and the external structure formed by soybean protein isolate (SPI) and phosphatidylserine (PS) was added on the basis of the internal structure to prepare walnut oil oleogel (SPI-PS-WOG). Ultrasonic treatment was applied to the mixed solution to make SPI-PS-WOG, on the basis, the effects of ultrasonic treatment on SPI-PS-WOG were investigated. The results showed that both β and β’ crystalline forms were present in all SPI-PS-WOG samples. When the ultrasonic power was 450 W, the first weight loss peak in the thermogravimetric (TGA) curve appeared at 326 °C, which was shifted to the right compared to the peak that occurred when the ultrasonic power was 0 W, indicating that the thermal stability of the SPI-PS-WOG was improved by the ultrasonic treatment. Moreover, when the ultrasonic power was 450 W, the oil holding capacity (OHC) reached 95.3 %, which was the best compared with other groups. Both confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) showed that the ultrasonic treatment of appropriate power succeeded in making the SPI-PS-WOG samples more evenly dispersed in the internal structure and denser in the external structure. In terms of oxidative stability, it was found that the peroxide value of SPI-PS-WOG remained at 9.8 mmol/kg oil for 50 days under 450 W ultrasonic power treatment, which was significantly improved compared with liquid walnut oil (WO). These results provide a new idea for the preparation of oleogels, and also lay a theoretical foundation for the application of ultrasonic treatment in oleogels.     

Effects of ultrasound on the degradation kinetics,physicochemical properties and prebiotic activity of Flammulina velutipes polysaccharide

The controllable ultrasonic modification was hindered due to the uncertainty of the relationship between ultrasonic parameters and polysaccharide quality. In this study, the ultrasonic degradation process was established with kinetics. The physicochemical properties and prebiotic activity of ultrasonic degraded Flammulina velutipes polysaccharides (U-FVPs) were investigated. The results showed that the ultrasonic degradation kinetic models were fitted to 1/M_t-1/M₀ = kt. When the ultrasonic intensity increased from 531 to 3185 W/cm², the degradation proceeded faster. The decrease of polysaccharide concentration contributed to the degradation of FVP, and the fastest degradation rate was at 60 °C. Ultrasound changed the solution conformation of FVP, and partially destroyed the stability of the triple helix structure of FVP. Additionally, the viscosity and gel strength of FVP decreased, but its thermal stability was improved by ultrasound. Higher ultrasonic intensity led to larger variations in physicochemical properties. Compared with FVP, U-FVPs could be more easily utilized by gut microbiota. U-FVPs displayed better prebiotic activity by promoting the growth of Bifidobacterium and Brautella and inhibiting the growth of harmful bacteria. Ultrasound could be effectively applied to the degradation of FVP to improve its physicochemical properties and bioactivities.     

Effects of ultrasound pretreatment on the quality,nutrients and volatile compounds of dry-cured yak meat

The objective of the present study was to assess the effects of ultrasound pretreatment on the quality of dry-cured yak meat. The ultrasonic power with 0, 200, 300 and 400 W (ultrasonic frequency of 20 kHz) were used to assist processing of dry-cured yak meat. The meat quality, nutrient substances, sensory quality, electronic nose, electronic tongue and volatile compounds of dry-cured yak meat were determined. The results indicated that the moisture content and hardness value of ultrasonic treatment group was significantly lower compared to the control group (P < 0.05). Ultrasonic treatment increased the value of b*, and decreased the value of L*, a*, pH, chewiness, melting temperature and enthalpy. Springiness value significantly increased from control group to 300 W of ultrasonic power group. Shear force significantly decreased with the increase of ultrasonic power (P < 0.05). Ultrasonic treatment had no effect on the TVB-N content, but it could increase the TBARS content. Ultrasonic treatment could significantly increase the essential FAA (EFAA) and total FAA (P < 0.05). In addition, the saturated fatty acid (SFA) content significantly increased with the increase of ultrasonic power (P < 0.05). Ultrasound treatment negatively affected the meat’s color, smell, and taste but increased its tenderness and the overall acceptability. It also significantly increased alcohols and aldehydes contents (P < 0.05), which were consistent with the measurement of electronic nose and electronic tongue. The results demonstrated that the the appropriate ultrasonic power assisted in the processing improves quality of dry-cured yak meat, particularly for the power of 300 W.     

Effect of ultrasonic power on properties of edible composite films based on rice protein hydrolysates and chitosan

Rice protein hydrolysates (RPH) are incapable of film formation by self-crosslinking due to low molecular mass. Hence, we used chitosan (CS) as a modifier and developed rice protein hydrolysates/chitosan (RPH/CS) edible composite films by means of ultrasound. Results showed that ultrasound treatment decreased the particle size and the viscosity of film-forming solutions. The value of elongation at break of composite films was increased by 125% at 400 W compared with untreated film. The peroxide value of soybean oil was significantly reduced from 16.99 ± 0.78 meq/kg to 2.23 ± 0.09 meq/kg with the increase of ultrasonic power. Ultrasound treatment was efficient in keeping smooth on surface, and the films at ultrasound treatment of 200 W had better compatibility. Moreover, hydrogen bonds and covalent interactions were probably the main forces between RPH and CS and contributed to film formation under ultrasound treatment, which supported by analyses of Fourier transform infrared spectroscopy and X-ray diffraction. These results suggested that ultrasound was an effective method to improve the properties of edible composite films.     

Ultrasound assisted co-precipitation of nanostructured CuO–ZnO–Al2O3 over HZSM-5: Effect of precursor and irradiation power on nanocatalyst properties and catalytic performance for direct syngas to DME

Nanostructured CuO–ZnO–Al₂O₃/HZSM-5 was synthesized from nitrate and acetate precursors using ultrasound assisted co-precipitation method under different irradiation powers. The CuO–ZnO–Al₂O₃/HZSM-5 nanocatalysts were characterized using XRD, FESEM, BET, FTIR and EDX Dot-mapping analyses. The results indicated precursor type and irradiation power have significant influences on phase structure, morphology, surface area and functional groups. It was observed that the acetate formulated CuO–ZnO–Al₂O₃/HZSM-5 nanocatalyst have smaller CuO crystals with better dispersion and stronger interaction between components in comparison to nitrate based nanocatalysts. Ultrasound assisted co-precipitation synthesis method resulted in nanocatalyst with more uniform morphology compared to conventional method and increasing irradiation power yields smaller particles with better dispersion and higher surface area. Additionally the crystallinity of CuO is lower at high irradiation powers leading to stronger interaction between metal oxides. The nanocatalysts performance were tested at 200–300 °C, 10–40 bar and space velocity of 18,000–36,000 cm³/g h with the inlet gas composition of H₂/CO = 2/1 in a stainless steel autoclave reactor. The acetate based nanocatalysts irradiated with higher levels of power exhibited better reactivity in terms of CO conversion and DME yield. While there is an optimal temperature for CO conversion and DME yield in direct synthesis of DME, CO conversion and DME yield both increase with the pressure increase. Furthermore ultrasound assisted co-precipitation method yields more stable CuO–ZnO–Al₂O₃/HZSM-5 nanocatalyst while conventional precipitated nanocatalyst lost their activity ca. 18% and 58% in terms of CO conversion and DME yield respectively in 24 h time on stream test.     

Combination of liquid-phase pulsed discharge and ultrasonic for saponins extraction from lychee seeds

A skillfully combined method of liquid-phase pulsed discharge and ultrasonic (LPDU) had been developed for saponins extraction from lychee seeds. Single factor and response surface methods were used to optimize the system, respectively. The optimized conditions included 30% aqueous ethanol, 62.66 mL/g ratio of liquid to solid, 3 mm centre hole diameter of hollow electrode, 123 mL/min flow velocity, length of serpentine pipe of 15 cm, 276 W ultrasonic power, 47 °C ultrasonic temperature, and discharge voltage was fixed at 14 kV. Under these conditions, it obtained a maximum saponins yield of 51.30 ± 0.08 mg/g with 10 min, which was higher than those of LPD (42.33 ± 0.98 mg/g) with 24 min, ultrasonic assisted extraction (UAE) (41.80 ± 1.31 mg/g) with 30 min and maceration (38.72 ± 1.13 mg/g) with 180 min. Meanwhile, the energy consumption of LPDU was 7560 kJ/kg, which was notably lower than those of LPD (8820 kJ/kg), UAE (25875 kJ/kg) and maceration (10248 kJ/kg). We found that the saponin constituents of LPDU were similar to LPD, UAE, ME by HPLC content detection method, and found that LPDU had the highest degree of tissue damage after scanning electron microscope (SEM) comparison, which verified the reason for its high extraction efficiency. The results showed that LPDU was an effective technology for saponins extraction, which may be potentially applied in cosmetics, medicines and food chemistry.     

Comparative study of ultrasonic pretreatment and ultrasound assisted three phase partitioning for extraction of custard apple seed oil

Custard apple seed oil is a marketable product extracted from custard apple seed which is a potential agriculture waste. The present work aims to elucidate simultaneous extraction of the custard apple seed oil and proteins using three phase partitioning (TPP). The efficient oil extraction was executed by optimization of parameters including time, slurry ratio, salt concentration, and slurry to t-butanol ratio. Additionally, the application of ultrasound as process intensification tool for TPP was studied that reduces the time of conventional TPP and increases the yield by 2.53%. The work also comprises a comparative study of two modes of ultrasound application, namely ultrasound pre-treatment and simultaneous ultrasound assisted TPP. This work proves ultrasonic pre-treatment followed by TPP as a superior mode of ultrasound application that attributes 33.6 ± 0.56% (w/w) oil extraction with optimized pre-treatment time of 150 s, 30 W ultrasound power and 75% duty cycle. Extraction kinetics studied for conventional, Ultrasound assisted Three Phase Partitioning (UTPP), and Ultrasound Pre-treatment assisted Three Phase Partitioning (UPTPP) were observed to fit Peleg’s model.     

Ultrasound-assisted desalination of crude oil: The influence of mixing extent,crude oil species,chemical demulsifier and operation variables

Coalescence of water droplets in crude oil has been effectively promoted by chemical demulsifiers integrated with ultrasound. Temporary images of water droplets in W/O emulsions were directly monitored using a metallurgical microscope. Water droplets achieved expansion of 118% at 40 min ultrasonic irradiation time under well mixing conditions. However, water droplets in heavy crude oil undergo less aggregation than those in light crude oil, due to resistance of mobility in highly viscous fluid. In the absence of chemical demulsifiers, water droplets enveloped by native surfactants appeared to aggregate arduously because of occurrence of interfacial tension gradients. Influential significance analyses have been executed by a factorial design method on operation variables, including acoustic power intensity, operation temperature, ultrasonic irradiation time and chemical demulsifier dosages. In this work, the outcomes indicate that the optimal operating conditions for desalination of crude oil assisted by ultrasound were as follows: acoustic power intensity = 300 W, operation temperature = 90℃, ultrasonic irradiation time = 75 min and chemical demulsifier dosages = 54 mg/L. Besides, it was found that the most influential importance of operation parameter was temperature, followed with acoustic power intensity, ultrasonic irradiation time and chemical demulsifier dosages.     

Ultrasonic-assisted electrodeposition of Cu-Sn-TiO2 nanocomposite coatings with enhanced antibacterial activity

Copper-based coatings are known for their high antibacterial activity. In this study, nanocomposite Cu–Sn–TiO₂ coatings were obtained by electrodeposition from an oxalic acid bath additionally containing 4 g/dm³ TiO₂ with mechanical and ultrasonic agitation. Ultrasound treatment was performed at 26 kHz frequency and 32 W/dm³ power. The influence of agitation mode and the current load on the inclusion and distribution of the TiO₂ phase in the Cu–Sn metallic matrix were evaluated. Results indicated that ultrasonic agitation decreases agglomeration of TiO₂ particles and allows for the deposition of dense Cu–Sn–TiO₂ nanocomposites. It is shown that nanocomposite Cu–Sn–TiO₂ coatings formed by ultrasonic-assisted electrodeposition exhibit excellent antimicrobial properties against E. coli bacteria.     

Effects of high power ultrasonic vibration on temperature distribution of workpiece in dry creep feed up grinding

Temperature history and distribution of steel workpiece (X20Cr13) was measured by a high tech infrared camera under ultrasonic assisted dry creep feed up grinding. For this purpose, a special experimental setup was designed and fabricated to vibrate only workpiece along two directions by a high power ultrasonic transducer. In this study, ultrasonic effects with respect to grinding parameters including depth of cut (a_e), feed speed (v_w), and cutting speed (v_s) has been investigated. The results indicate that the ultrasonic vibration has considerable effect on reduction of temperature, depth of thermal damage of workpiece and width of temperature contours. Maximum temperature reduction of 25.91% was reported at condition of v_s = 15 m/s, v_w = 500 mm/min, a_e = 0.4 mm in the presence of ultrasonic vibration.     

Enzymatic catalyzed palm oil hydrolysis under ultrasound irradiation: Diacylglycerol synthesis

Diacylglycerol (DAG) rich oils have an organoleptic property like that of regular edible oils, but these oils do not tend to be accumulated as fat. Palm oil ranks first in the world in terms of edible oil production owing to its low cost. The aim of this study was to propose a new methodology to produce diacylglycerol by hydrolysis of palm oil using Lipozyme RM IM commercial lipase as a catalyst under ultrasound irradiation. The reactions were carried out at 55 °C with two different methods. First, the reaction system was exposed to ultrasonic waves for the whole reaction time, which led to enzymatic inactivation and water evaporation. Ultrasound was then used to promote emulsification of the water/oil system before the hydrolysis reaction, avoiding contact between the probe and the enzymes. An experimental design was used to optimize the ultrasound-related parameters and maximize the hydrolysis rate, and in these conditions, with a change in equilibrium, DAG production was evaluated.Better reaction conditions were achieved for the second method: 11.20 wt.% (water + oil mass) water content, 1.36 wt.% (water + oil mass) enzyme load, 12 h of reaction time, 1.2 min and 200 W of exposure to ultrasound. In these conditions diacylglycerol yield was 34.17 wt.%.     

Structural and physicochemical properties of lotus seed starch nanoparticles prepared using ultrasonic-assisted enzymatic hydrolysis

Lotus seed starch nanoparticles were prepared by ultrasonic (ultrasonic power: 200 W, 600 W, 1000 W; time: 5 min, 15 min, 25 min; liquid ratio (starch: buffer solution): 1%, 3%, 5%) assisted enzymatic hydrolysis (LS-SNPs represent lotus seed starch nanoparticles prepared by enzymatic hydrolysis and U-LS-SNPs represent lotus seed starch nanoparticles prepared by high pressure homogenization-assisted enzymatic hydrolysis). The structure and physicochemical properties of U-LS-SNPs were studied by laser particle size analysis, scanning electron microscope, X-ray diffraction, Raman spectroscopy, nuclear magnetic resonance and gel permeation chromatography system. The results of scanning electron microscopy showed that the surface of U-LS-SNPs was cracked and uneven after ultrasonic-assisted enzymolysis, and there was no significant difference from LS-SNPs. The results of particle size analysis and gel permeation chromatography showed that the particle size of U-LS-SNPs (except 5% treatment group) was smaller than that of LS-SNPs. With the increase of ultrasonic power and time, the weight average molecular gradually decreased. The results of X-ray diffraction and Raman spectroscopy showed that ultrasonic waves first acted on the amorphous region of starch granules. With the increase of ultrasonic power and time, the relative crystallinity of U-LS-SNPs increased first and then decreased. The group (600 W, 15 min, 3%) had the highest relative crystallinity. The results of nuclear magnetic resonance studies showed that the hydrogen bond and double helix structure of starch were destroyed by ultrasound, and the double helix structure strength of U-LS-SNPs was weakened compared with LS-SNPs. In summary, U-LS-SNPs with the small-sized and the highest crystallinity can be prepared under the conditions of ultrasonic power of 600 W, time of 15 min and material-liquid ratio of 3%.     

Ultrasonic assisted water-in-oil emulsions encapsulating macro-molecular polysaccharide chitosan: Influence of molecular properties,emulsion viscosity and their stability

An ultrasonic technique was applied to formulation of two-phase water-in-paraffin oil emulsions loading a high-molecular polysaccharide chitosan (CS) and stabilized by an oil-soluble surfactant (Span80) at different operational conditions. The influence of chitosan molecular properties, phase volume ratio (φ_w), Span80 volume fraction (φ_s) and ultrasonic processing parameters were systemically investigated on the basis of mean droplet diameter (MDD) and polydispersity index (PDI) of emulsions. It was observed that the molecular weight (M_w) of CS was an important influential factor to MDD due to the non-Newtonian properties of CS solution varying with M_w. The minimum MDD of 198.5 nm with PDI of 0.326 was obtained with ultrasonic amplitude of 32% for 15 min at an optimum φ_w of 35%, φ_s of 8%, probe position of 2.2 cm to the top of emulsion, while CS with M_w of 400 kDa and deacetylation degree of 84.6% was used. The rise of emulsion viscosity and the reduction of negative zeta potential at φ_w increasing from 5% to 35% were beneficial to obtain finer droplets and more uniform distribution of emulsions, and emulsion viscosity could be represented as a monotonically-decreasing power function of MDD at the same φ_w. FTIR analysis indicated that the molecular structure of paraffin oil was unaffected during ultrasonication. Moreover, the emulsions exhibited a good stability at 4 °C with a slight phase separation at 25 °C after 24 h of storage. By analyzing the evolution of MDD, PDI and sedimentation index (SI) with time, coalescence model showed better fitting results as comparison to Ostwald ripening model, which demonstrated that the coalescence or flocculation was the dominant destabilizing mechanism for such W/O emulsions encapsulating CS. This study may provide a valuable contribution for the application of a non-Newtonian macromolecule solution as dispersed phase to generate nano-size W/O emulsions via ultrasound, and widen knowledge and interest of such emulsions in the functional biomaterial field.     

Exploring the influence of ultrasound on the antibacterial emulsification stability of lysozyme-oregano essential oil

A lysozyme-oregano essential oil (Lys-OEO) antibacterial emulsion was developed via ultrasonic treatment. Based on the general emulsion materials of ovalbumin (OVA) and inulin (IN), the addition of Lys and OEO successfully inhibited the growth of E. coli and S. aureus, two representatives of which were Gram-negative and Gram-positive bacteria respectively. The emulsion system in this study was designed to compensate for the limitation that Lys could only act on Gram-positive bacteria, and the stability of the emulsion was improved using ultrasonic treatment. The optimal amounts among OVA, Lys and OEO were found to be the mass ratio of 1:1 (Lys to OVA) and 20% (w/w) OEO. The ultrasonic treatment at the power of 200, 400, 600, and 800 W and time length of 10 min improved the stability of emulsion, in which the surface tension was below 6.04 mN/m and the Turbiscan stability index (TSI) did not exceed 10. The multiple light scattering showed that sonicated emulsions were less prone to delamination; salt stability and pH stability of emulsions were improved, CLSM image showed emulsion as oil-in-water type. In the meantime, the particles of the emulsions were found to become smaller and more uniform with ultrasonic treatment. The best dispersion and stability of the emulsion were both achieved at 600 W with a zeta potential of 7.7 mV, the smallest particle size and the most uniform particle distribution.     

Tea saponin additive to extract eleutheroside B and E from Eleutherococcus senticosus by ultrasonic mediation and its application in a semi-pilot scale

The safety of ethanol in operations and its effects on human health are gradually being questioned. Under this premise, we attempted to use the natural surfactant tea saponin, which originates from the processing residues of camellia oil, as the additive of the extraction solvent and to extract eleutheroside B and eleutheroside E in the roots and rhizomes of E. senticosus by ultrasonic mediation. After a single-factor experiment, extraction kinetics at different powers and reaction temperatures, and Box–Behnken design optimization, the optimal conditions obtained were 0.3% tea saponin solution as the extraction solvent, 20 mL/g liquid–solid ratio, 250 W ultrasonic irradiation power (43.4 mW/g ultrasonic power density) and 40 min ultrasonic irradiation time. Under optimal conditions, satisfactory yields of eleutheroside B (1.06 ± 0.04 mg/g) and eleutheroside E (2.65 ± 0.12 mg/g) were obtained with semi pilot scale ultrasonic extraction equipment. The experiments showed that compared with the traditional thermal extraction process, the extraction time is significantly reduced at lower operating temperatures.     

Non-thermal pasteurization of lipid emulsions by combined supercritical carbon dioxide and high-power ultrasound treatment

Supercritical carbon dioxide (SC-CO₂) is a novel method for food pasteurization, but there is still room for improvement in terms of the process shortening and its use in products with high oil content. This study addressed the effect of high power ultrasound (HPU) on the intensification of the SC-CO₂ inactivation of E. coli and B. diminuta in soybean oil-in-water emulsions. Inactivation kinetics were obtained at different pressures (100 and 350 bar), temperatures (35 and 50 °C) and oil contents (0, 10, 20 and 30%) and were satisfactorily described using the Weibull model. The experimental results showed that for SC-CO₂ treatments, the higher the pressure or the temperature, the higher the level of inactivation. Ultrasound greatly intensified the inactivation capacity of SC-CO₂, shortening the process time by approximately 1 order of magnitude (from 50 to 90 min to 5–10 min depending on the microorganism and process conditions). Pressure and temperature also had a significant (p < 0.05) effect on SC-CO₂ + HPU inactivation for both bacteria, although the effect was less intense than in the SC-CO₂ treatments. E. coli was found to be more resistant than B. diminuta in SC-CO₂ treatments, while no differences were found when HPU was applied. HPU decreased the protective effect of oil in the inactivation and similar microbial reductions were obtained regardless of the oil content in the emulsion. Therefore, HPU intensification of SC-CO₂ treatments is a promising alternative to the thermal pasteurization of lipid emulsions with heat sensitive compounds.     

Ultrasonic-assisted synthesis of nano-sized metal-organic framework; a simple method to explore selective and fast Congo Red adsorption

A novel mixed linker Metal-organic Framework, [Co(NH₂IsoBDC)(bpfn)].DMF (TMU-69), with amide and amino functionalized spacers (bpfn = N,N'-(naphthalene-1,5-diyl)diisonicotinamide, NH₂IsoBDCH₂ = 5-Aminoisophthalic acid) was synthesized through both solvothermal and ultrasonic approaches. Applying sonochemical irradiation led to ultrafast formation of Flower-shaped nanoplates of TMU-69 within 15 min with high yield while, solvothermal method takes 3 days to form the framework. Control of size and morphology was also enhanced through applying ultrasonic irradiations. The implication of applied time and concentration of reagents on size and morphology of nano-structured TMU-69 have been optimized. Applying higher concentration of initial material with optimized 60-minute irradiation forms uniform smaller sized nanoplates of TMU-69. Also, the efficiency of TMU-69 bulk and nanoplates toward removal of pollutant dyes from water was investigated. The selective adsorption of Congo Red was observed among other dyes. Also, drastic enhancement in removal kinetic of Congo Red through using ultrasonic assisted nanoplates of TMU-69 was obtained.     

Ultrasound assisted enzymatic depolymerization of aqueous guar gum solution

The present work investigates the effectiveness of application of low intensity ultrasonic irradiation for the intensification of enzymatic depolymerization of aqueous guar gum solution. The extent of depolymerization of guar gum has been analyzed in terms of intrinsic viscosity reduction. The effect of ultrasonic irradiation on the kinetic and thermodynamic parameters related to the enzyme activity as well as the intrinsic viscosity reduction of guar gum using enzymatic approach has been evaluated. The kinetic rate constant has been found to increase with an increase in the temperature and cellulase loading. It has been observed that application of ultrasound not only enhances the extent of depolymerization but also reduces the time of depolymerization as compared to conventional enzymatic degradation technique. In the presence of cellulase enzyme, the maximum extent of depolymerization of guar gum has been observed at 60 W of ultrasonic rated power and ultrasonic treatment time of 30 min. The effect of ultrasound on the kinetic and thermodynamic parameters as well as the molecular structure of cellulase enzyme was evaluated with the help of the chemical reaction kinetics model and fluorescence spectroscopy. Application of ultrasound resulted in a reduction in the thermodynamic parameters of activation energy (E_a), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) by 47%, 50%, 65% and 1.97%, respectively. The changes in the chemical structure of guar gum treated using ultrasound assisted enzymatic approach in comparison to the native guar gum were also characterized by FTIR. The results revealed that enzymatic depolymerization of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency index without any change in the core chemical structure which could make it useful for incorporation in food products.