Composition and Functional Properties of Soy Protein Isolates Prepared Using Alternative Defatting and Extraction Procedures
Article first published online: 30 JUN 2006
Journal of Food Science
Volume 71, Issue 3, pages C137–C145, April 2006
How to Cite
L'hocine, L., Boye, J. I. and Arcand, Y. (2006), Composition and Functional Properties of Soy Protein Isolates Prepared Using Alternative Defatting and Extraction Procedures. Journal of Food Science, 71: C137–C145. doi: 10.1111/j.1365-2621.2006.tb15609.x
- Issue published online: 30 JUN 2006
- Article first published online: 30 JUN 2006
- MS 20050552 Submitted 9/13/05, Revised 10/14/05, Accepted 1/5/06.
- soybean defatting;
- protein aqueous extraction;
- functional properties;
- protein functionality;
- soybean protein isolate
ABSTRACT: In this study, the effects of alcohol defatting using ethanol, methanol, and non-alcoholic aqueous extraction methods on the yield, purity, and functionality of soy protein isolates were investigated. Soy protein extraction conditions were also modified (heat and mild acidic treatment before protein alkaline extraction, heat isoelectric precipitation, and non-neutral resolubilization of proteins), and the effects on the isolate properties were evaluated. Results showed that ethanol and aqueous extraction were potential alternatives to hexane. The soy protein isolates (SPI) obtained from these samples had protein contents of more than 90% and 84%, respectively, with functional properties comparable to those of SPI prepared from hexane defatted meal. Major differences were a decrease in the emulsifying activity properties of the SPIs resulting from the alternative defatting techniques, with, however, improved emulsion stability and foaming properties for the aqueous extracted SPIs. A marked decrease in the fat-holding capacity of the SPI made from methanol defatted meal was also noted. Modifying the protein isolation procedure also greatly influenced the functional properties of soy protein isolates. The results of the present investigation demonstrate that soy processing conditions can be modified to obtain soy proteins ingredients with specific functional properties.