Soy Protein

Name: Soy protein — protein extracted from soybeans, sold as soy flour, soy protein concentrate (about 70% protein) and soy protein isolate (about 90% protein), used in protein powders, bars, meat substitutes, baked goods and infant formula. It is a complete protein.

Description

Soy protein products are made by removing the oil from soybeans, then removing some or most of the carbohydrates, which leaves a protein-rich powder. They became widely used in food manufacturing in the second half of the 20th century, and today appear in many processed foods, from sausages and burgers to protein bars and nutrition shakes.

Soy is one of the few plant proteins that contains all nine essential amino acids in good amounts, and its protein digestibility is high, comparable to animal proteins. It is also a refined, ultra-processed ingredient that is taken out of its original whole-food form.

Main nutrition value

Soy protein is a high-quality, complete plant protein, with the fibre and some of the vitamins of the whole bean largely removed, and isolates are low in fat and carbohydrate.

How best to be consumed

Soy protein is a supplement and food ingredient.

1. Blend soy protein powder into smoothies, porridge, pancakes and baking, in place of some flour.
2. Choose unflavoured or lightly sweetened products, and read the label for added sugar and sweeteners.
3. Use it to top up protein as part of a varied diet, rather than as a replacement for whole foods such as tofu, tempeh and beans.
4. Mix with plenty of liquid to avoid a gritty texture.
5. Store in a cool, dry place, sealed.

Overconsumption could cause…

Soy protein is generally well tolerated, with a few points to know.

1. Soy allergy, which can be serious in some people, particularly children, so anyone allergic must avoid soy and check labels.
2. Possible effects on thyroid medicine absorption, so people taking levothyroxine should leave several hours between it and soy foods, and soy can matter for people with low iodine intake or an underactive thyroid.
3. Isoflavones, plant compounds in soy that weakly mimic oestrogen, which research suggests are safe in food amounts for most people, including those with a history of breast cancer, although very high supplement doses are not advised.
4. Digestive upset such as gas and bloating from powders, particularly in large servings.
5. Added sugar, sweeteners and additives in flavoured products.

GroupsSoy FoodsLegume familyHigh proteinHigh sodiumRich in folateRich in ironRich in zinc

Made fromSoybeans

Related foodsNattoMisoTempehFirm TofuTofuFermented Tofu

Wikipedia — Soy protein, used for origin, naming and history: https://en.wikipedia.org/wiki/Soy_protein