Milk proteins: Physicochemical and functional properties

Abstract

Because of the growing trend toward widespread use of protein ingredients in food formulation and fabrication, an understanding of the relationships between the physical properties of proteins and their behavior in food systems is desirable. A range of milk-derived protein preparations, i.e., dry milk, milk proteins, caseins, whey proteins, and lactalbumin, are used in a range of food products for their specific functional attributes. In this paper some of the apparent relationships between the properties of the protein components and specific functional properties are discussed. Thus, the roles of milk proteins in determining some important physical characteristics (i.e. color, bulk density, sinkability, dispersibility) of milk powders and their involvement in a range of functional properties (water holding, solubility, rheological behavior, gelation, film formation, emulsification, and foaming) are reviewed. Because of the various methods and conditions used in determining functional properties and the variability in composition of preparations it is difficult to compare data and/or reconcile differences in published information. The desirability of developing standard methods is emphasized.

Albumen protein and functional properties of gelation and foaming

“…If the attractive strengths predominate, a coagulum is formed, and water is driven off the network matrix. If the repulsive strengths dominate, a three-dimensional network can not be formed (Kinsella, 1984).…”

“…In homogenous systems, the main attractive strengths are hydrogen bounds, hydrophobic interactions, electrostatic and van der Waals forces (Kinsella, 1984). The strength magnitude, which keeps the native protein structure either in solution or at the interface, is important in the foaming properties (Adamson, 1982).…”

“…The physical integrity of gels depends on the balance between attractive and repulsive strengths of the protein molecules involved in the system (Hermanssom, 1979;Schmidt, 1981;Kinsella, 1984;Mulvihill & Kinsella, 1987;Ziegler & Foegeding, 1990). If the attractive strengths predominate, a coagulum is formed, and water is driven off the network matrix.…”

Avaliação sensorial de sorvete formulado com produto de soro ácido de leite bovino

“…Observou-se que o SAP apresenta menor teor protéico, teor em carboidratos mais elevado e alto teor em minerais (14%) comparativamente ao leite em pó desnatado, em conformidade com o esperado e registrado por outros autores [6,8,16].…”

“…rável de utilizações [16], necessitando de processamento para tornar-se o ingrediente protéico adequado para uma utilização específica [13]. Países como Estados Unidos, Austrália, Canadá e Nova Zelândia e nações da União Européia processam este subproduto reconhecendo-o como ingrediente funcional e agregando valor à linha de produção da indústria látea.…”