Film forming and foaming behavior of food proteins

Abstract

The current state of understanding of protein structure as it relates to its function in foaming has proven to be of sufficient accuracy to predict the effects of particular modifications in soy proteins. Comparative whipping studies performed on egg white, casein, Bovine serum albumin and soy protein showed important differences both in the development and subsequent stability of foams produced from these proteins. Our understanding of the structures of soy proteins and the alterations induced by reductive modification and heating implied that similar modifications would have dramatic impact on the foaming properties specifically of the 11S protein. The foaming ability and stability of the 11S protein were enhanced dramatically by cleavage of intersubunit disulfide bridging. Computerized lamellar measurement techniques developed in this laboratory indicated that these modifications enhanced the ability of the protein to foam rapidly and then to stabilize surface films at the rate typically encountered in the whipping of foams.

Enzymatic hydrolysis of defatted soy flour by three different proteases and their effect on the functional properties of resulting protein hydrolysates

“…3 and 4. Soy proteins were suggested to have poor foaming properties due to their large, compact structure (GERMAN et al 1985). Enzyme treatment increased the height of foam (HF), but foam stability was markedly decreased in each instance.…”

Estimation of Foam Stability by Parameters in the Capillary Model

“…If k' is constan t irrespecti ve of ma terials as they stated, no physical properties of the liquid except viscosity and density are related to the liquid leakage rate, i.e., the foam stability (see Eqs. (4), (6), (9), (10), and (11)). As is known well, foam stability is different even between materials with the same viscosity and density.…”

Effect of Acid Treatment on Interfacial and Foam Properties of Soy Proteins

“…This globular trimeric protein is held together by hydrophobic interactions when the ionic strength is more than 0.5 [5]. Soy proteins have been reported to be poor foaming agents, mainly because their compact structure is not prone to absorb and unfold at the film interface, which is necessary for an adequate film formation [6]. Sorgentini et al [7] studied the effects of thermal and acid treatments on soy protein isolates (SPI) and the 11S globulin, showing that the functional properties of these proteins improved after treatment.…”