Soy protein isolate
Soy protein isolate suppliers and sourcing guide
Soy protein isolate is the most refined form of soy protein, at about 90% protein on a dry basis. Dehulled, defatted soybean flakes are extracted with mildly alkaline water, the fiber is removed, and the protein is precipitated with acid, washed, neutralized and spray dried. Suppliers sell many grades that differ in viscosity, gelling and dispersibility for drinks, bars, meat products and meat analogs.
- Category
- Proteins and amino acids
- Also known as
- isolated soy protein · ISP · SPI · Glycine max protein isolate
- Facts checked
- November 2026
Forms and grades of soy protein isolate
Suppliers sell different products under the same name. Specify the one you need.
Dispersible beverage grade
Low-viscosity isolate that mixes into shakes and ready-to-drink products.
Gelling grade
Higher-viscosity isolate used to bind water and fat in meat products, analogs and emulsions.
Non-GMO and identity-preserved
Isolate from identity-preserved non-GMO soybeans, often with third-party verification.
Organic
Isolate from certified organic soybeans, offered by fewer suppliers.
Hydrolyzed
Enzyme-treated isolate with lower viscosity for bars that need to stay soft.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Protein (Kjeldahl or Dumas)
- Total nitrogen times 6.25, usually reported on a dry basis with a minimum near 90%.
- Moisture, fat, ash and pH
- Proximate analysis plus pH of a dispersion, which affects solubility and taste.
- GMO testing
- PCR testing for genetically modified soy events on non-GMO grades, with the threshold stated.
- Microbiology
- Total plate count, coliforms, yeast and mold, Salmonella and E. coli.
- Heavy metals
- Lead, arsenic, cadmium and mercury by ICP-MS against the buyer's limits.
- Viscosity or gel strength
- Functional specs for the grade, measured on a standard dispersion.
Storage, lots and expiry
Storage and shelf life
Store sealed, cool and dry, off the floor and away from odors; the powder takes up moisture and flavors. Shelf life is set by the supplier's specification, commonly with a retest of moisture, micro and sensory for aged stock.
Lots and expiry dates
Record protein, viscosity and non-GMO documentation for each lot. Beany flavor and color can vary between lots, so keep retained samples for sensory comparison.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
FDA's Substances Added to Food inventory lists soy protein isolate with the technical effects emulsifier or emulsifier salt, formulation aid, nutrient supplement, stabilizer or thickener, and texturizer.
Source: hfpappexternal.fda.gov (opens in a new tab)Health Canada's Workout Supplements monograph lists soy protein isolate with the seed of Glycine max (soybean) as the source material.
Source: webprod.hc-sc.gc.ca (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
Soy protein isolate suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking soy protein isolate suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell soy protein isolate? Request a listingFrequently asked questions
What forms of soy protein isolate can brands buy?
Common forms include dispersible beverage grade, gelling grade, non-GMO and identity-preserved, organic and hydrolyzed. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for soy protein isolate include?
Expect protein (Kjeldahl or Dumas), moisture, fat, ash and pH, gMO testing, microbiology, heavy metals and viscosity or gel strength, each with its method, specification and result for that lot.
How should soy protein isolate be stored?
Store sealed, cool and dry, off the floor and away from odors; the powder takes up moisture and flavors. Shelf life is set by the supplier's specification, commonly with a retest of moisture, micro and sensory for aged stock.
What is the regulatory status of soy protein isolate?
FDA's Substances Added to Food inventory lists soy protein isolate with the technical effects emulsifier or emulsifier salt, formulation aid, nutrient supplement, stabilizer or thickener, and texturizer. Health Canada's Workout Supplements monograph lists soy protein isolate with the seed of Glycine max (soybean) as the source material.
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