L. Bazinet et al., Effect of temperature on the separation of soybean 11 S and 7 S protein fractions during bipolar membrane electroacidification, BIOTECH PR, 16(2), 2000, pp. 292-295
The purpose of this study was to evaluate the effect of temperature (10 and
27 degrees C) on the efficiency of bipolar membrane electroacidification (
BMEA) to fractionate soybean proteins. BMEA is a technology derived from el
ectrodialysis, based on the isoelectric precipitation of proteins. It appea
rs that temperature has a significant effect on the selective precipitation
of the soybean protein fractions, mainly 11 S and 7 S, during BMEA. At 27
degrees C, the precipitation profile of the four protein fractions is situa
ted in a pH range from 6.6 to 4.4, with no possibility of separating any of
theses fractions However, at 10 degrees C, the 11 S globulin precipitates
at a higher pH than at 27 degrees C, pH 6.7 vs 5.9, allowing the fractionat
ion of 11 S from the other fractions. Using electroacidification it is poss
ible to obtain a precipitate solution enriched in the 11 S fraction (71.8%
of 11 S and 10.8% of 7 S) and a supernatant solution enriched in the 7 S fr
action (46.6% of 7 S and 4.6% of 11S).