Effect of Soy Protein Subunit Composition on the Rheological Properties of Soymilk during Acidification |
| |
Authors: | Amir Malaki Nik Marcela Alexander Vaino Poysa Lorna Woodrow Milena Corredig |
| |
Institution: | (1) Department of Food Science, University of Guelph, Guelph, ON, Canada, N1G2W1;(2) Agriculture and Agri-Food Canada, Greenhouse and Processing Crops Research Centre, 2585 Country Road 20, Harrow, ON, Canada, N0R 1G0; |
| |
Abstract: | The effect of soy protein subunit composition on the acid-induced aggregation of soymilk was investigated by preparing soymilk
from different soybean lines lacking specific glycinin and β-conglycinin subunits. Acid gelation was induced by glucono-δ-lactone
(GDL) and analysis was done using diffusing wave spectroscopy and rheology. Aggregation occurred near pH 5.8 and the increase
in radius corresponded to an increase in the elastic modulus measured by small deformation rheology. Diffusing wave spectroscopy
was also employed to follow acid gelation, and data indicated that particle interactions start to occur at a higher pH than
the pH of onset of gelation (corresponding to the start of the rapid increase in elastic modulus). The protein subunit composition
significantly affected the development of structure during acidification. The onset of aggregation occurred at a higher pH
for soymilk samples containing group IIb (the acidic subunit A3) of glycinin, than for samples prepared from Harovinton (a commercial variety containing all subunits) or from genotypes
null in glycinin. The gels made from lines containing group I (A1, A2) and group IIb (A3) of glycinin resulted in stiffer acid gels compared to the lines containing only β-conglycinin. These results confirmed that
the ratio of glycinin/β-conglycinin has a significant effect on gel structure, with an increase in glycinin causing an increase
in gel stiffness. The type of glycinin subunits also affected the aggregation behavior of soymilk. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|