Protein-stabilized foams and emulsions

Milk proteins: physicochemical and functional properties

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.

Modification of plant proteins by immobilized proteases

A potential application of plant proteins could be a replacement of animal proteins now in use in the food industry on the basis of certain specific functional properties plant proteins have. Modification of the chemical structure of selected plant proteins is needed to replace more expensive animal proteins as food ingredients that have specific functional characteristics. Structure modification may be achieved by physical, chemical, or microbiological methods, or by a combination of these. Immobilized enzyme techniques offer significant advantages for protein modification. Knowledge of the molecular properties of plant proteins is essential to understand the basis of protein functionality, to modify proteins so that they acquire desirable functional properties, and to predict potential applications of modified plant proteins. This paper reviews all the above mentioned aspects of plant protein chemistry and potential utilization.

Functionality of muscle constituents in the processing of comminuted meat products

Emulsification through the creation of a fat dispersion and formation of an interfacial protein membrane at the fat-water interface is not the sole aspect responsible for comminuted meat "emulsion" stability. In addition, water binding which occurs initially during myofibrillar protein extraction from tissue disruption, and later during entrapment within the heat-induced protein gel matrix, must be included. The criteria that affect formation of the gel matrix adds another aspect, in that conditions for optimum protein-protein interaction also influence ultimate water and fat stabilization. Rheological considerations are in their infancy and will require future study, particularly during the transformation of a "flowing" batter into a "nonflowing" solid product. This review has been aimed at emphasizing that the myofibrillar protein component is the predominant constituent involved in an interactive role with water, fat, and itself, in forming the ultimate stabilized comminuted meat matrix.