Compositional Factors That Affect the Emulsifying and Foaming Properties of Whey Protein Concentrates

Abstract

An emulsion containing 30% fat was used to study emulsifying and foaming properties of commercial whey protein concentrates. Residual lipids, both total and phospholipids, inhibited foaming of dilute aqueous solutions of whey protein concentrates, whereas in aerated emulsions residual lipids were positively correlated with foaming. Under both test conditions the ash content was positively correlated with good and moderate foaming properties. Among the compositional factors which best predicted foaming of emulsions were sulfnydryls. Emulsions which contained insoluble whey proteins were highly stable but air incorporation was poor. When soluble whey proteins were utilized to stabilize emulsions, serum separation occurred more readily but did not correlate with good foaming properties.

Emulsifying Properties of Lipid‐Reduced, and Calcium‐Reduced Whey Protein Concentrates

“…The correlation between k T and WPC ash content (P Ͻ 0.10) was consistent with previous reports on the importance of ionic strength and emulsifying properties of proteins (Tornberg, 1978;Peltonen-Shalaby and Mangino 1986;Klemaszewski et al, 1992). Calcium content of WPC did not correlate with WPC emulsifying properties.…”

“…Primary independent variables for the k T model included percentage of BSA, Ca content and protein solubility and with an R 2 of 0.65. The factors protein solubility, ash content, calcium content, and total SH, have been reported by others (PeltonenShalaby and Mangino, 1986;Liao and Mangino, 1987).…”

Foaming and Emulsifying Properties of Whey Protein Concentrates As Affected by Lipid Composition

“…Similar negative correlations had been found between total and free fats and foaming capacity, between bound fat and foam stability, and between free fat and emulsifying capacity. Positive correlations between ash and calcium contents and foaming properties were reported Peltonen-Shalaby and Mangino, 1986). Phospholipids and DAG contents negatively correlated with emulsifying capacity.…”

Testing protein functionality

“…Reproducibility depended on the method of sample dissolution, type of whisking accessory fitted to the mixer, bowl shape, sampling, and the time elapsed before measuring foam drainage. Peltonen-Shalaby and Mangino 40 found, using eight different WPC samples, that foaming overrun was 770 (Ô164)% compared to 248 (Ô19)% for whipping overrun (next section). 41 Some investigators refer to whipping by virtue of the type of mixer used; food foams can be prepared by shaking, whipping or sparging.…”