Gelatin isoionic point

Coa.cerva.tlon, A phenomenon associated with coUoids wherein dispersed particles separate from solution to form a second Hquid phase is termed coacervation. Gelatin solutions form coacervates with the addition of salt such as sodium sulfate [7757-82-6] especially at pH below the isoionic point. In addition, gelatin solutions coacervate with solutions of oppositely charged polymers or macromolecules such as acacia. This property is useful for microencapsulation and photographic apphcations (56—61). 

Amide groups may be hydrolyzed to carboxyl and amine by either alkaline treatment (leading to Type B gelatin) or extended acid degradation (Type A). This loss of amide groups and its relation to the isoionic point has been studied by Eastoe with the results shown in Table 2. 

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