The structure and function of protein are strongly pH-dependence.However,the inonization state of the protein varied with the pH value also depends on the local structure and environment of protein.It is not same as t...The structure and function of protein are strongly pH-dependence.However,the inonization state of the protein varied with the pH value also depends on the local structure and environment of protein.It is not same as those of free residues in solution.To get more detail information from the structural change,molecular simulation is widely used.Bovine serum albumin(BSA)is the most abundant protein and commonly used auxiliary drug in the biochemical experiments.It is the natural protein with single free cysteine.We used BSA as model protein to investigate the pH induced local environmental and conformational changes with molecular simulation and fluorescent methodology.展开更多
The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions.In this work,we mainly explore the effect of pH change on the droplet and creaming s...The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions.In this work,we mainly explore the effect of pH change on the droplet and creaming stability of fish oil-loaded emulsions synergistically(Span 80 and SL)or competitively(Tween 80 and SDS)stabilized by gelatin/surfactant.The results demonstrated that initial droplet stability and droplet storage stability,and creaming stability of the pH-adjusted emulsions are dependent on both the adsorption ways of emulsifiers and the adjusted pH:(1)Competitively stabilized emulsions have more stable droplets than synergistically stabilized emulsions;(2)SDS-dominant competitively stabilized emulsions have more stable droplets than gelatin-dominant emulsions;(3)Basic pH-adjusted emulsions have more stable droplets than acidic pH-adjusted emulsions;(4)The synergistically stabilized emulsions at acidic pH have significantly higher creaming indexes than that at basic pH;and(5)The competitively stabilized emulsions have high or similar creaming indexes to that at acidic pH.Further,the mechanisms are proposed according to Stokes’Law.This work will provide useful information to understand the interfacial properties of mixed emulsifiers in the food emulsions and promising application perspective for the development of food beverages including acidic and alkali beverages.展开更多
Geode, boudinage, and undulation structures are widely distributed in the siliceous beds of the Upper Cretaceous/Tertiary rocks in Jordan. Their formation was attributed to tectonic forces, syngenetic processes, organ...Geode, boudinage, and undulation structures are widely distributed in the siliceous beds of the Upper Cretaceous/Tertiary rocks in Jordan. Their formation was attributed to tectonic forces, syngenetic processes, organic disintegration processes, subaquatic gliding, compaction and settlement, and meteoritic impacts. In this work, the structural features in the siliceous beds of Jordan are attributed to an interplay of load and directed pressures, and mineralogical transformation processes (opal-A to opal-CT to quartz), governed by pH changes. Tectonic directed pressure was acting in an ESE-WSW direction and is common in the silicified limestone of Upper Cretaceous.展开更多
文摘The structure and function of protein are strongly pH-dependence.However,the inonization state of the protein varied with the pH value also depends on the local structure and environment of protein.It is not same as those of free residues in solution.To get more detail information from the structural change,molecular simulation is widely used.Bovine serum albumin(BSA)is the most abundant protein and commonly used auxiliary drug in the biochemical experiments.It is the natural protein with single free cysteine.We used BSA as model protein to investigate the pH induced local environmental and conformational changes with molecular simulation and fluorescent methodology.
基金supported by research grants from the National Key R&D Program of China(No.2019YFD0902003)Shanghai Municipal Education Commission-Gaoyuan Discipline of Food Science&Technology Grant Support(Shanghai Ocean University).
文摘The droplet and creaming stability of food emulsions stabilized by mixed emulsifiers is a research hotspot in the field of emulsions.In this work,we mainly explore the effect of pH change on the droplet and creaming stability of fish oil-loaded emulsions synergistically(Span 80 and SL)or competitively(Tween 80 and SDS)stabilized by gelatin/surfactant.The results demonstrated that initial droplet stability and droplet storage stability,and creaming stability of the pH-adjusted emulsions are dependent on both the adsorption ways of emulsifiers and the adjusted pH:(1)Competitively stabilized emulsions have more stable droplets than synergistically stabilized emulsions;(2)SDS-dominant competitively stabilized emulsions have more stable droplets than gelatin-dominant emulsions;(3)Basic pH-adjusted emulsions have more stable droplets than acidic pH-adjusted emulsions;(4)The synergistically stabilized emulsions at acidic pH have significantly higher creaming indexes than that at basic pH;and(5)The competitively stabilized emulsions have high or similar creaming indexes to that at acidic pH.Further,the mechanisms are proposed according to Stokes’Law.This work will provide useful information to understand the interfacial properties of mixed emulsifiers in the food emulsions and promising application perspective for the development of food beverages including acidic and alkali beverages.
文摘Geode, boudinage, and undulation structures are widely distributed in the siliceous beds of the Upper Cretaceous/Tertiary rocks in Jordan. Their formation was attributed to tectonic forces, syngenetic processes, organic disintegration processes, subaquatic gliding, compaction and settlement, and meteoritic impacts. In this work, the structural features in the siliceous beds of Jordan are attributed to an interplay of load and directed pressures, and mineralogical transformation processes (opal-A to opal-CT to quartz), governed by pH changes. Tectonic directed pressure was acting in an ESE-WSW direction and is common in the silicified limestone of Upper Cretaceous.
