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.

No abstract

No abstract

The structural properties, i.c., active sulfhydryl (SH), flexibility and hydrophobicity, and functional properties, i.e., solubility,. emulsion activity (EA), emulsion stability (ES), foam overrun (FO) and foam stability (FS), of commercial sodium caseinate (SC) and whey protein isolate (WPI) solutions were investigated.at pH 6, 7 and 8 and at 25, 55 and 65°C. WPI contained a higher concentration of active SH and was more hydrophobic than SC. WPI provided comparable solubility and EA, lower FO, but higher FS than SC. Temperature and pH effects on the two proteins were somewhat inconsistent.

The effect of three different soaking treatments (6 hr in 50°C water; 6 hr in 50°C 0.25% NaHCO, solution; or 30 min in boiling 0.25% NaHCO, solution) was studied on the production of the major isoflavone aglucones, daidzein and genistein, and headspace volatile organic compounds including aldehydes, alcohols and furans in soybeans. Both 50" treatments resulted in production of substantial amounts of isoflavone aglucones and headspace volatile organic compounds. The boiling NAHCO, treatment inhibited production of isoflavone aglucones and lowered total headspace volatile organic compounds.