Whey and whey proteins-From 'gutter-to-gold'

There is abundant information concerning the functional behavior of whey proteins in model systems. The data on functional properties reported by different researchers, however, reveal wide discrepancies in values. For example, in the case of comparable whey preparations, apparent solubilities may range from 10 to 100%; strength of gels from 0.3 to greater than 10 N, foam overruns from 250 to 1500%, and foam stabilities from 0.5 to 30 min. Many of the data are of limited value in assessing the true functional characteristics of different preparations, treatments, or processing effects. Reports to date are useful in indicating the relative behavior of different proteins; however, the data do not always predict the performance of such proteins in actual food systems. This reflects the fact that in foods, extensive interactions with other components may occur, resulting in modified behavior of the proteins. Harper, (1984) has advocated the testing of these various preparations in simulated food systems which should validly relate the behavior to performance in commercial systems. Emphasis on standardization of specific protocols, with regard to order of addition in ingredients, temperature, pH control, and amount of energy input during mixing, homogenization, emulsification, etc. deserves serious consideration. While this approach is justifiable in terms of providing valuable data to commercial users, it does not minimize the importance of examining these proteins in model systems where the physicochemical basis of each functional attribute can be described in molecular terms (Kinsella, 1987). Such information is necessary to expedite appropriate methods of processing in order to control compositional variability, extent of denatauration, and possible protein modification. In addition, rapid, reliable tests for routine quality assurance that can provide practical information concerning functional applications would be of great value. Whey protein preparations vary immensely in functional behavior and are presently relegated to limited use as functional ingredients in the food industry. This need not be the case since conventional and new technologies permit rigorous control of production protocols, e.g., careful control of heat treatments can result in the production of whey protein preparations with consistent, reliable functional properties (deWit, 1981, 1984; Harper, 1984; Morr, 1985). As the market for functional proteins continues to expand, the whey industry must seek the means to refine whey protein products; determine useful functional properties; develop standardized manufacturing protocols; demonstrate the effectiveness of whey as a functional ingredient; promote, and then market, whey on the basis of performance at competitive cost.

Proteins in whey: chemical, physical, and functional properties

Substantial progress has been made in understanding the basic chemical and structural properties of the principal whey proteins, that is, beta-lactoglobulin (beta-Lg), alpha-lactalbumin (alpha-La), bovine serum albumin (BSA), and immunoglobulin (Ig) This knowledge has been acquired in terms of: (1) procedures for isolation, purification, and characterization of the individual whey proteins in buffer solutions; and (2) whey fractionation technologies for manufacturing whey protein concentrates (WPC) with improved chemical and functional properties in food systems This article is a critical review of selected publications related to (1) whey fractionation technology for manufacturing WPC and WPI; (2) fundamental properties of whey proteins; and (3) factors that affect protein functionality, that is, composition, protein structure, and processing

Whey protein concentrates and isolates: Processing and functional properties

Rheological Properties of Foods, H. Dogan and J. L. Kokini Reaction Kinetics in Food Systems, R. Villota and J. G. Hawkes Phase Transitions and Transformations in Food Systems, Y. H. Roos Transport and Storage of Food Products, M.A. Rao Heating and Cooling Processes for Foods, R. P. Singh Food Freezing, D. R. Heldman Mass Transfer in Foods, B. Hallstroem, V. Gekas, I. Sjoeholm, and A. M. Romulus Evaporation and Freeze, K. R. Morison and R. W. Hartel Membrane Concentration of Liquid Foods, M. Cheryan Food Dehydration, M. R. Okos, O. Campanella, G. Narsimhan, R. K. Singh, and A. C. Weitnauer Thermal Processing of Canned Foods, A. Teixeira Extrusion Processes, L. Levine and R. C. Miller Food Packaging, J. M. Krochta Cleaning and Sanitation, E. A. Plett and A. Grasshoff Appendix Index

V. Bernal

Papers

Thermal Stability of Whey Proteins – A Calorimetric Study

Effect of Calcium Binding on Thermal Denaturation of Bovine α-Lactalbumin