Soy protein isolate

Soy protein isolate is a fine, off-white powder made by removing most of the fat and carbohydrate from soybeans, leaving behind an almost pure protein concentrate. It is most often stirred into smoothies and protein shakes, or used as a functional ingredient in veggie burgers, meat extenders, and processed foods where it binds moisture and adds structure. On its own it has a mild, slightly beany flavor and a chalky texture, so it is usually blended with milk, fruit, oats, or nut butter rather than eaten plain. It also shows up in commercial bread and cereal bars as a way to raise protein content without changing texture much.

Because it is a concentrated powder, soy protein isolate keeps well in a sealed container in a cool, dry pantry for months, and a little goes a long way, delivering 88.3 grams of protein per 100 grams. It is also rich in iron, providing 81% of the Daily Value per 100 grams, useful for cooks building plant-based meals around iron-containing ingredients. With 1000 milligrams of sodium per 100 grams, it is worth checking labels and adjusting added salt elsewhere in a recipe. It works best folded into a dish rather than served as a standalone food.