Title of article :
Physico-chemical factors controlling the foamability and foam stability of milk proteins: Sodium caseinate and whey protein concentrates
Author/Authors :
Krastanka G. Marinova، نويسنده , , Elka S. Basheva، نويسنده , , Boriana Nenova، نويسنده , , Mila Temelska، نويسنده , , Amir Y. Mirarefi، نويسنده , , Bruce Campbell and Louise Scott ، نويسنده , , Ivan B. Ivanov، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2009
Pages :
13
From page :
1864
To page :
1876
Abstract :
We explored the foaming behavior of the two main types of milk proteins: flexible caseins and globular whey proteins. Direct foam comparison was complemented with measurements in model experiments such as thin foam films, dynamic surface tension, and protein adsorption. Foaming was studied as a function of pH (from below to above isoelectric point, pI) and range of ionic strengths. Maximum foamability was observed near pI ≈ 4.2 for WPC in contrast to sodium caseinate which had minimum foaming near pI = 4.6. Good foamability behavior correlated well with an increased adsorption, faster dynamic surface tension decrease and increased film lifetime. Differences in the stability of the foams and foam were explained with the different molecular structure and different aggregation behavior of the two protein types. Far from its isoelectric pI, casein adsorption layers are denser and thicker thus ensuring better stabilization. Added electrolyte increased further the adsorption and the repulsion between the surfaces (probably by steric and/or osmotic mechanism). In contrast the globular molecules of WPC probably could not compact well to ensure the necessary films and foams stabilization far from pI, even after electrolyte addition.
Keywords :
Protein adsorption , pH dependence , Foam , Sodium caseinate , Whey protein concentrate
Journal title :
Food Hydrocolloids
Serial Year :
2009
Journal title :
Food Hydrocolloids
Record number :
979023
Link To Document :
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