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This study aimed to explore the effect of ultrasound-assisted pH shift on the structural and functional properties of soybean lipophilic proteins (SLP). SLP were modified under ultrasound (240 W, 20 min) and extreme pH (pH 1 or 12) conditions. The primary, secondary and tertiary structures of native and modified SLP were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), free sulfhydryl content, Fourier transform infrared (FTIR) spectroscopy, and fluorescence spectroscopy, and their functional properties were analyzed. The results showed that ultrasound-assisted alkaline pH shift resulted in the greatest changes in the structural and functional properties of SLP. The average particle size of SLP decreased from 5 245.33 to 447.13 nm, the ζ-potential value decreased from − 5.95 to − 18.53 mV, the free sulfhydryl content decreased, the α-helix content increased, and the fluorescence spectrum exhibited a blue shift and a decrease in fluorescence intensity. In addition, the solubility increased from 9.84% to 92.04%, and the emulsifying and foaming properties increased. Therefore, ultrasound and pH shift treatments have a synergistic effect on the structural and functional properties of SLP, and they are closely correlated with each other.

The purpose of this study was to understand the stability of natural emulsions formed from soybean oil bodies (SOB) extracted at alkaline pH (8.0–11.0) and their digestive properties in the gastrointestinal tract. The stability of SOB was evaluated in terms of its basic composition, particle size, zeta potential and rheology, and the digestive properties were evaluated in terms of fatty acid release from SOB and the microstructure of SOB. The results showed that with an increase in extraction pH, the water and protein contents of SOB decreased and the particle size decreased from (471.57 ± 8.53) nm to (424.77 ± 12.21) nm, while the lipid content increased. In addition, the oxidative stability of SOB showed a similar trend. Specifically, the peroxide value (POV) decreased with increasing extraction pH and the thiobarbituric acid reactive substances (TBARS) value increased with an increase in storage time. The apparent viscosity decreased with increasing shear rate. SOB emulsions showed shear thinning behavior with G’ being greater than G” for all samples, and the release percentage of free fatty acids from SOB significantly increased with increasing extraction pH (P < 0.05). This study provides theoretical support for the wide application of highly stable natural SOB.

In this study, soybean oil bodies were used as raw materials and emulsifiers to prepare soybean oil body complex emulsions by ultrasonication, to optimise the ultrasonication conditions and to use the oil body complex emulsions for the transport of fat-soluble bioactives. The mechanism of ultrasonic treatment to enhance the stability of oil-body complex emulsions was revealed through the study of the physicochemical properties of the emulsions. The effect of oil-body complex emulsions on the transport of β-carotene was also examined. As a result, soybean oil body complex emulsion was successfully prepared by ultrasonication, and the oxidative and storage stability of the emulsion was best at a power of 450 W (10 min). At this time, the average particle size of emulsion was 1537 nm, and the shape of droplets was round and evenly distributed. The results of Fourier transform infrared spectroscopy indicated that the ultrasound-induced cavitation effect increased the physical forces, such as turbulence and shear forces. This caused partial unfolding of the protein polypeptide chains in oil bodies, leading to the rearrangement of hydrogen bond networks within the proteins. Consequently, the protein secondary structure changed: The relative content of α-helix structures decreased and the relative content of β-sheet structures increased. The electrophoresis results showed that there were no significant changes in the composition of protein subunits. But with the ultrasound intensity increased, the adsorption of extrinsic proteins at the droplet interface was enhanced. The results of storage stability showed that ultrasonic treatment (450 W) could inhibit the generation of oxidation products and improved the oxidation stability of emulsions. The soybean oil body-β-carotene emulsions could be successfully prepared by ultrasonic treatment, and the encapsulation rate of β-carotene was the highest (94.9%) at 450 W, and the retention rate was 81.8% after 11 days of room temperature storage. This study provides insights into the application of soybean oil bodies as emulsifiers for the delivery of fat-soluble bioactive substances. [ABSTRACT FROM AUTHOR]

Objective: To detect the expression of microRNA-107 （miR-107） and the calcium channel protein gene CACNA2D1 in laryngeal cancer tissues, to investigate the targeting relationship between miR-107 and CACNA2D1 , and to analyze the effects of miR-107 on the proliferation, invasion and colony forming ability of laryngeal cancer cells. Method: Laryngeal cancer tissues and normal adjacent tissue samples from 40 patients with laryngeal cancer were collected, and qRT-PCR was used to detect the expression of miR-107 and CACNA2D1 ; Western Blot assay to detect the expression of α2δ1 in the above two tissues; the dual-luciferase reporter gene was used to detect the regulatory effect of miR-107 on CACNA2D1 ; after overexpression or knockdown of miR-107 in human laryngeal cancer cells TU212 and TU686, changes in the proliferation, clone formation, and invasion ability of laryngeal cancer cells were detected. Result: The expression of miR-107 in laryngeal cancer tissues was significantly lower than that in adjacent normal tissues, while the expression of CACNA2D1 was just the opposite, the difference was statistically significant （ P <0.05）; the expression of α2δ1 in laryngeal cancer tissues is significantly higher than in normal tissues（ P <0.05）; dual-luciferase reporter experiments confirmed that miR-107 binds to the 3'-UTR （202-209, 902-908） of the CACNA2D1 mRNA, thereby inhibiting the expression of CACNA2D1 and its biological effects; cell experiments showed that the proliferation, invasion, and clone formation of laryngeal cancer cells were significantly reduced after miR-107 overexpression （ P <0.05）, and the cell proliferation, clone formation, and invasion were significantly enhanced after miR-107 was knocked down （ P <0.05） . Conclusion: miR-107 inhibits the proliferation, clone formation, and invasion of laryngeal cancer cells by targeting CACNA2D1 ., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)