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Tofu is nutritious, easy to make, and popular among consumers. At present, traditional tofu production has gradually become perfect, but there are still shortcomings, such as long soaking time, serious waste of water resources, and the inability to realize orders for production at any time. Moreover, tofu production standards have not yet been clearly defined, with large differences in quality between them, which is not conducive to industrialized and large‐scale production. Ultrasound has become a promising green processing technology with advantages, such as high extraction rate, short processing time, and ease of operation. This review focused on the challenges associated with traditional tofu production during soaking, grinding, and boiling soybeans. Moreover, the advantages of ultrasonic processing over traditional processing like increasing nutrient content, improving gel properties, and inhibiting the activity of microorganisms were explained. Furthermore, the quantification of acoustic fields by real‐time monitoring technology was introduced to construct the theoretical correlation between ultrasonic treatments and tofu processing. It was concluded that ultrasonic treatment improved the functional properties of soybean protein, such as solubility, emulsifying properties, foamability, rheological properties, gel strength, and thermal stability. Therefore, the application of ultrasonic technology to traditional tofu processing to optimize industrial parameters is promising. [ABSTRACT FROM AUTHOR]

[Display omitted] • The pretreatment efficiency of SFUS was higher than FFUS. • Recommended conditions for SFUS + DES were 40 kHz, 60 min, ChCl-LA, 120 °C, 3 h. • The SFUS + DES pretreatment resulted in 85.62% LRR of SCB. • After SFUS + DES pretreatment, enzymatic hydrolysis of SCB yielded 86.76% glucose. • The hydrogen bonding of DES Cl- and lignin was responsible for lignin removal. Sugarcane bagasse (SCB) is an abundant agricultural waste in China and the conversion of the waste into plethora of useful resources is very vital. To achieve this, fractionation of the waste is highly important in the biomass biorefinery. The present study aims at investigating the synergistic role of deep eutectic solvents (DES) with sweeping frequency ultrasound (SFUS) and fixed frequency ultrasound (FFUS) in the fractionation of SCB to enhance the enzymatic saccharification process. Therefore, the effects of ultrasound (US) and DES conditions on the pretreatment efficiency were investigated. Under optimum SCB pretreatment conditions, FFUS (40 kHz, 60 min) + DES (choline chloride (ChCl)-lactic acid (LA), 120 °C, 3 h) and SFUS (40 kHz, 60 min) + DES (ChCl-LA, 120 °C, 3 h), the lignin removal rates were 80.13 and 85.62%, respectively. The hemicellulose removal rates were 78.08 and 90.46%, respectively; and the contents of glucose, xylose and arabinose in the liquid fractions after FFUS + DES pretreatment were 7.07, 17.95 and 3.01%, respectively. However, the yield of glucose, xylose, and cellobiose after enzymatic hydrolysis of the SFUS + DES pretreated SCB were 86.76, 38.68, and 20.76%. Analytical studies revealed that the SFUS + DES pretreatment can effectively destroy the ultrastructure of SCB and reduce the crystallinity of cellulose. Furthermore, the mechanism of pretreatment with SFUS + DES was proposed, which confirmed the excellent performance of SFUS + DES. Thus, the application of SFUS + DES pretreatment was able to improve the removal of lignin and hemicellulose from SCBs. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to investigate the effect of ultrasound-ionic liquid (IL) pretreatment on the enzymatic and acid hydrolysis of the sugarcane bagasse and wheat straw. The lignocellulosic biomass was dissociated in ILs ([Bmim]Cl and [Bmim]AOC) aided by ultrasound waves. Sonication was performed at different frequencies (20, 28, 35, 40, and 50 kHz), a power of 100 W, a time of 30 min and a temperature of 80 °C. The changes in the structure and crystallinity of the cellulose were studied by Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). The amounts of the total reducing sugars, glucose, cellobiose, xylose and arabinose in the hydrolysates were determined. The results of FT-IR, XRD and TGA revealed that the structure of cellulose of both biomass samples remained intact after the pretreatment, but the crystallinity decreased. The enzymatic and acid hydrolysis of the biomass samples pretreated with the ultrasound-IL result in higher yields of the reducing sugars compared with the IL-pretreated sample. Enzymatic hydrolysis of bagasse and wheat straw pretreated with [Bmim]Cl-ultrasound resulted in maximal yields of glucose at 20 kHz (40.32% and 53.17%) and acid hydrolysis resulted in maximal yields of glucose at 40 kHz (33.32% and 48.07%). Enzymatic hydrolysis of bagasse and wheat straw pretreated with [Bmim]OAc-ultrasound show maximal yields of glucose at 28 kHz and acid hydrolysis at 50 kHz. Combination of ultrasound with [Bmim]OAc is more effective than [Bmim]Cl in terms of the yields of reducing sugar. [ABSTRACT FROM AUTHOR]

Developing a number of zein distribution mechanisms that encapsulate hydrophobic nutraceuticals has become a hot topic in food industry. In this study, the multi-frequency ultrasound-assisted dialysis method was used to fabricate stable nanoparticles. The ultrasound working mode and sodium caseinate modulated physicochemical properties, molecular interactions and microstructure of the nanoparticles system. The optimal ultrasonic frequency of 20/40 kHz resulted in Zein-sodium caseinate particle size, zeta potential and PDI values of 225.94 ± 3.84 nm, - 29.97 ± 1.49 mv, and the 0.19 ± 0.08, respectively. Additionally, ultrasound and Sodium Caseinate have a synergistic effect in improving the storage stability of nanoparticles. The results of fluorescence and CD demonstrated that ultrasound promoted the interaction between Sodium Caseinate and zein, by changing the local microenvironment and structure of the protein. FTIR results showed that the dominant driving force in the formation of hybrid nanoparticles was hydrophobic interaction, hydrogen bond and electrostatic interaction. Ultrasound-assisted dialysis was an effective strategy to encapsulate curcumin. XRD showed that curcumin was successfully encapsulated, and the 20/40 kHz ultrasound frequency combination improved encapsulation rate by 90.19 ± 0.33% as well as thermal stability, storage stability and antioxidant activity of curcumin (86.91 ± 0.72%). AFM and SEM showed uniform and regular spherical structure of composite nanoparticles. The findings revealed not only the multi-mode ultrasound assisted dialysis could be utilized to encapsulate hydrophobic bioactive compounds, which constructed delivery system, but also it provided a controlled release under simulated gastrointestinal conditions, and a better protection and desirable sustained-release of hydrophobic nutraceuticals. [Display omitted] • Multi-frequency ultrasound aided dialysis generated alcohol-free Zein-NaCas nanoparticles. • Ultrasound and NaCas had a synergistic effect on stability of nanoparticles. • Multi-frequency ultrasound improved Cur's environmental tolerance and Cur exhibited better sustained-release. • Multi-frequency ultrasound improved Cur loading rate and antioxidant activity. • Zein nanoparticles and Cur conjugated by H-bonding and hydrophobic interactions. [ABSTRACT FROM AUTHOR]