Origin of Water Loss from Soy Protein Gels

Abstract

Water holding (WH) of soy protein gels was investigated to identify which length scales are most contributing to WH when centrifugal forces are applied. More specifically, it was attempted to differentiate between the contributions of submicron and supramicron length scales. MgSO4 and MgCl2 salt specificities on soy protein aggregation (submicron contribution) were used to create different gel morphologies (supramicron contribution). Obtained results showed that the micrometer length scale is the most important contribution to WH of gels under the applied deformation forces. WH of soy protein gels correlated negatively with Young's modulus and positively with recoverable energy. The occurrence of rupture events had only a limited impact on WH. The ease by which water may be removed from the gel, but not the total amount, seemed to be related to the initial building block size. These insights could be exploited in product development to predict and tune oral perception properties of (new) products.

Relating water holding of ovalbumin gels to aggregate structure

“…In addition, an easier water removal from coarser gels was indicated by the decreased minimal needed force (g min ). The lower WH was related to a coarser microstructure and a lower Young's modulus, in line with literature, (Maltais et al, 2005;Urbonaite et al, 2015;Urbonaite et al, 2014) and was therefore indirectly related to aggregate size and density. Furthermore, a direct relation between aggregate density and water holding was present, with a higher WH for more open aggregates that contained more water.…”

“…Water holding measurements were performed as described by Urbonaite et al (Urbonaite et al, 2014) In short, a microcentrifuge filtration unit was composed of an inner spin tube and a 2 mL Eppendof tube (Axygen Biosciences, Inc., Union City, CA, USA). Gels were cut in 10 mm height and 4.8 mm diameter cylinders using a cork borer and carefully placed on the bottom of the spin tube.…”

“…The relation between gel stiffness and water holding was found to be system specific and to be either positive or negative. (Chantrapornchai & McClements, 2002;Croguennec, Nau, & Brule, 2002;Furukawa & Ohta, 1982;Maltais, Remondetto, Gonzalez, & Subirade, 2005;Urbonaite, de Jongh, van der Linden, & Pouvreau, 2015;Urbonaite, de Jongh, van der Linden, & Pouvreau, 2014) Gels with a fine microstructure are reported to have a higher water holding capacity than more coarse gels. (Chantrapornchai & McClements, 2002;Croguennec et al, 2002;Handa, Takahashi, Kuroda, & Froning, 1998;Kitabatake, Shimizu, & Doi, 1988;Maltais et al, 2005;Pares, Saguer, Saurina, Sunol, & Carretero, 1998; However, protein networks with similar microstructure were found to differ in water holding due to the interplay between gel stiffness and microstructure.…”

“…(Chantrapornchai & McClements, 2002;Croguennec et al, 2002;Handa, Takahashi, Kuroda, & Froning, 1998;Kitabatake, Shimizu, & Doi, 1988;Maltais et al, 2005;Pares, Saguer, Saurina, Sunol, & Carretero, 1998; However, protein networks with similar microstructure were found to differ in water holding due to the interplay between gel stiffness and microstructure. (Urbonaite et al, 2015(Urbonaite et al, , 2014.…”

Water-binding of protein particles

“…In literature, several definitions can be found, various terms are utilized, and different methods are used to determine the WBC. [30][42] [77][85] [148] Therefore, the WBC as such does not exist, and needs further specification.…”