Silken tofu was prepared using a soak procedure described previously
(Yang & James, 2013). Briefly, the beans were soaked in
deionised water at 15 C for around 16 h to allow full imbibition.
The soaked beans were drained and rinsed before being weighed
to determine the quantity of water imbibed. Fresh deionised water
was then added and the content homogenised. The slurry was
placed in a water bath at 98 C for 15 min. The soymilk was
extracted by centrifugation from the hot slurry and collected and
its weight recorded. The solid content of the soymilk was derived
from soymilk moisture content. The solid yield of soymilk was calculated
as the percentage of total solids in soymilk over those in
seeds. Soymilk was allowed to cool to room temperature before a
coagulant was added and curd was then placed in an 85 C water
bath for 35 min. The tofu was stored at 4 C overnight before analyses.
The coagulant used was nigari (containing mostly magnesium
chloride, food-grade ingredient from The Melbourne Ingredient
Depot, Victoria, Australia) and was added to the soymilk at a concentration
of 0.3%.