Typical SDS–PAGE profiles for the four groups of soybeans with
high or low protein content and with or without the globulin
polypeptide 11SA4 are shown in Fig. 1. The bands were identified
according to the molecular weight of the protein ladder used and
also well-established data in the literature. The percentage of
major subunits for b-conglycinin (7S) and glycinin (11S) within
each band was calculated using densitometry. The major protein
(s) identified in the SDS–PAGE bands using nano-LC/MS/MS and
data base searches are presented in Table 1.
The mean squares from the analysis of variance revealed some
significant impacts that the protein content or the absence of
11SA4 had on seed characteristics and soymilk and tofu quality
(Table 2). Protein content significantly influenced seed weight,
seed imbibition, soymilk proteins and solid content, tofu colour
and tofu gel hardness. No significant effects of protein content on
seed moisture and oil content and tofu gel water loss were
observed. The effect of protein content on the profile of seed storage
proteins was limited to 7Sa0 , total 7S and total 7S+11S. In comparison,
and as expected, the absence of 11SA4 highly significantly
influenced the profile of seed storage proteins, with the notable
exception of total 7S+11S. Significantly, lack of 11SA4 affected seed
size, tofu gel hardness and water loss. Except for seed size and the
proportion of total 7S, however, there were no significant protein
content 11SA4 interactions.
The mean values for seed characteristics and tofu gel quality
attributes for the four groups: high protein+11SA4, high
protein11SA4, low protein+11SA4 and low protein11SA4, and
the pooled means for high or low protein contents and for those