The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI)

The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI) were investigated in this study. Flaxseed gum with 0.05-0.5% (w/v) concentration was used together with 1% (w/v) SPI to emulsify 10% (v/v) soybean oil. The emulsion was analyzed for emulsion activity (turbidity), stability, particle size, surface charge, and rheological properties. The turbidity and absolute zeta-potential values decreased initially by the addition of flaxseed gum and subsequently increased with further increase in the gum concentration to reach their peak around 0.35% (w/v) gum. The particle size of the emulsion decreased and reached a minimum value at 0.1% (w/v) gum concentration. Any increase in gum concentration beyond this value resulted into increase in the particle size. This study would help to widen the application of SPI and flaxseed gum mixture, and also contribute to the understanding of protein-gum interaction in emulsion. (C) 2010 Elsevier Ltd. All rights reserved.