Soya Flour

The type of soya flour normally used for biscuits is made from soya beans after the oil has been extracted (low fat soya flour). It is a major source of protein (the protein content is 50%) for dietary biscuits. There is a small level of lecithin present and this is a natural emulsifier which aids dough development. The disadvantage of using soya flour as a source of emulsifier is that more water is needed in the dough which can make baking more critical.

There are claims that biscuits using about 3 or 4% of soya flour based on the wheat flour content have better appearance, better eating quality and longer shelf life than those without soya flour.

There is probably some value in considering soya flour as a replacement for egg in a recipe because it is cheaper and like egg yolk has the emulsifier lecithin. When used in wafer batters the release of the bake wafers from the plates is improved.

Other soya flours which are available vary in their protein, fat and moisture contents. It is possible to obtain soya protein isolates with protein values as high as 98% on a dry basis.

Soya protein does not, of course, produce gluten.

As soya flour is used in relatively low quantities it is handled in bags. In cool dry conditions it is stable for long periods.