Ultrasound-assisted free radical modification on the structural and functional properties of ovalbumin-epigallocatechin gallate (EGCG) conjugates

The influence of ultrasound-assisted free radical modification on the structure and functional properties of ovalbumin-epigallocatechin gallate (OVA-EGCG) conjugates was investigated by experimental measurements and computer simulations. Compared with the traditional free radical condition, the ultrasonic-assisted processing significantly increased the conjugating efficiency of OVA and EGCG and shortened the conjugating from 24 h to 1 h without affecting the equivalent amount of EGCG conjugating. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis and multi-spectroscopy analysis (Fourier transform infrared spectroscopy, intrinsic fluorescence spectroscopy, and UV spectroscopy) indicated that the covalent conjugates could be formed between OVA and EGCG. And modification in the conformation of OVA was induced by EGCG. Furthermore, molecular docking results demonstrated the possession of high-affinity EGCG binding location on OVA, supporting and clarifying the experimental results. In addition, the functional properties of OVA including emulsification (emulsifying activity and emulsion stability) and antioxidant properties (DPPH scavenging capacity and ABTS scavenging capacity) were significantly improved after conjugation with EGCG, especially in ultrasound-assisted conditions. Overall, OVA-EGCG conjugates produced by ultrasound-assisted free radical treatment could be applied as a potential emulsifier and antioxidant, thereby expanding the application of OVA as a dual-functional ingredient.     

Study of the structure and spectral properties of radical anions of Zn complexes of porphyrins by the method of density functional theory

The structure, solvation energies, and electronic absorption spectra of possible products of the reaction of Zn porphin (Zn-P) with metallic sodium are calculated using methods of density functional theory. Calculated solvation energies of free and bound ions make it possible to assume that, in commonly used aprotic solvents, reduction products occur as \([Na^ + \cdot Zn - P^ - ]_{N, C_m } \) anion-cation contact pairs, with Na⁺ lying along either the NN or C _m C _m axis. This conclusion is consistent with results of calculations of electronic absorption spectra and of modeling of spectral manifestations of the electron photodetachment in frozen matrices.     

Recent advances in the application of ultrasound in dairy products: Effect on functional,physical, chemical,microbiological and sensory properties

Alternative methods for improving traditional food processing have increased in the last decades. Additionally, the development of novel dairy products is gaining importance due to an increased consumer demand for palatable, healthy, and minimally processed products. Ultrasonic processing or sonication is a promising alternative technology in the food industry as it has potential to improve the technological and functional properties of milk and dairy products. This review presents a detailed summary of the latest research on the impact of high-intensity ultrasound techniques in dairy processing. It explores the ways in which ultrasound has been employed to enhance milk properties and processes of interest to the dairy industry, such as homogenization, emulsification, yogurt and fermented beverages production, and food safety. Special emphasis has been given to ultrasonic effects on milk components; fermentation and spoilage by microorganisms; and the technological, functional, and sensory properties of dairy foods. Several current and potential applications of ultrasound as a processing technique in milk applications are also discussed in this review.     

全新的电导率特征矩阵方法及其在石墨烯THz频率光学特性上的应用

基于麦克斯韦方程组所要求的电磁场边界条件首次从理论上严格推导得到超薄导电体及其复合多层介质结构光学特性的一般计算方法及其特征矩阵公式, 其优点在于只要借助于导电体的电导率而无需知道其介电常数和磁导率即可计算得到反射、透射和吸收等光学特性, 克服了传统的传输矩阵方法必需知道组成材料的介电常数和磁导率才能获得其光学性质的问题, 并利用此方法获得了石墨烯及其复合多层结构在THz频率范围内反射、透射和吸收等光学行为.