Okara: Nutritious Byproduct of Soy Milk Production

Okara is the insoluble fibre- and protein-rich residue left behind when soybeans are ground, soaked and their liquid portion extracted — the by-product generated during the processing of soybeans in the food industry, specifically during the production of soy milk and tofu. Rather than a waste stream, it is a valuable ingredient in its own right, because of its nutritional content and its versatility across food formats.

The volumes involved make okara a material planning question for any soy processing plant. Approximately 1.5 to 2.0 kilograms of okara per kilogram of soybeans is generated during soymilk production, though this can vary based on several factors, including the soybean variety, processing methods, and the desired consistency of the soymilk. The process flow that produces it runs from soybean cleaning, through soaking (optional) and grinding (wet or dry), to slurry cooking and then okara isolation — separation by decanters, or by centrifuge and filtration — which splits the soy base (liquid) from the solid okara fraction.

Nutritionally, okara offers protein at 3-4 gm, fibre at 3-4 gm, carbohydrates at 5-7 gm and fat at 1-2 gm. It contains various vitamins, including B vitamins such as folate, thiamin (vitamin B1) and riboflavin (vitamin B2), along with small amounts of vitamin K.

Downstream, okara finds a place in plant-based meat alternatives such as veggie burgers, sausages and meatballs, where it improves texture and adds protein; in baked goods like muffins, pancakes and bread, to enhance moisture content and nutritional profile; as a thickening agent in soups, stews and sauces in place of traditional dairy-based thickeners; in desserts such as puddings, ice creams and cheesecakes for a creamy texture and added protein; as a base for dairy-free cheese, often combined with nutritional yeast and seasonings; processed and dried into powdered supplements or protein isolates; and as an ingredient in animal feed.