文档介绍：FOAM
Foam formation
Foam is usually some gas bubbles in continuous liquid or half fixed phase scattered by the formation of decentralized system.
foam formation
surface tension increase
bubbles break in a period of time
The relationship between time and foam volume
Drainage rate and Marangoni effect
gravity, pressure difference and evaporation lead to the foam drainage, reducing the thickness of the thin layer
Protein effects
1 adsorption is fast in gas-liquid interface
2 surface tension quickly reduce
3 viscous membrane generates in the interaction
of protein molecules
Roles of protein in bubbles
In gas-liquid interface, adsorption decreases the interfacial tension,
at the same time ,on the adsorption membrane protein produces the necessary rheological properties and stable effect.
Foaming ability
Foam stability
Foam properties
PH
Because of isoelectric point of proteins, the PH value will influnce the protein stable function
the effect of PH on
the foam stability
Salts and carbohydrates
Salts not only affect protein’s dissolution, viscosity, stretching and aggregation, they also affect its properties
Carbohydrates usually inhibit protein’s foaming ability, but it can increase the viscosity of protein solution, so it can improve foam stability
Salts and carbohydrates effect on foaming ability
No carbohydrates
Sucrose added