howdy folks,
Just wanted to mention that soy protein powder, or isolate, is NOT the same thing as soy FLOUR, and will give totally different results in baking...
Soy FLOUR is basically ground up soybeans, that have been partially cooked (to inactivate the phytate enzymes, which make the beans extremely difficult to digest otherwise). It may or may not be defatted. Full fat soy flour is yellowish in colour, and VERY strong beany tasting. And it goes rancid quickly. YUCK! Lowfat soy flour is paler, like unbleached all-purpose flour, and less-strong tasting. Its flavour can be improved by toasting briefly in a dry skillet (keep stirring, or it will burn) The lowfat flour is slightly higher in carbs than the full fat, 33.4 carbs/9 fiber vs. 29.2 carbs/8 fiber for 1 cup (85 gm).
(still less than wheat flour, which is 95 carbs per cup!)
Soy protein isolate is a highly refined product, which has all or most of the starch and carbohydrate removed. It's 90% or higher protein. Some brands are zero carbs, some have a trace, usually less than 2%. A few brands have added lecithin, and they may be flavoured as well, vanilla or chocolate. There are a number of soy shake powders on the market, promoting the isoflavones and benefits for menopause symptoms, often containing other herbs, cranberry extract, ginseng and who knows what all. They are way HIGH in carbs, 8 to 14 or even 20 gm per serving, because they are typically sweetened with fructose (sugar).
Breads, biscuits, damper, scones and the like require the starch in soy FLOUR to give the texture and structure we expect. Even so, because soy flour has less starch than wheat flour, the results will certainly be different from what we're used to from our HIGH carb baking days! ..
... The protein isolate mostly is added to bump up the protein content in a recipe, and it does provide a bit of texture, especially when used with eggs. But, substituting the protein powder for soy FLOUR (in hopes of creating a very lowcarb bread or whatever) will yield very disappointing results.
Oh, one more thing .... soy FLOUR, because of the starch and oil content must be stored in the fridge to keep it from going rancid once the package is opened.
Hope this has been helpful ..
Doreen