Cornstarch, also known as cornflour, is a common ingredient used as a thickener and stabilizer in many foods. It is extracted from the endosperm of corn kernels through a processing method that removes protein but leaves starch behind. Plain cornstarch is naturally gluten-free.
What is modified cornstarch?
Modified cornstarch refers to cornstarch that has been chemically altered to improve its functional properties. The most common modifications include pregelatinization, acid hydrolysis, and cross-linking. These modifications allow the cornstarch to produce optimal viscosity with less material, withstand higher processing temperatures, and remain stable throughout shelf life.
Pregelatinized cornstarch is created by partially gelatinizing the starch in water, then drying it back down. This allows the starch to rapidly swell and thicken when reintroduced to water, without needing heat. Acid-hydrolyzed cornstarch has been broken down slightly by acid to reduce its molecular weight. Cross-linked cornstarch has been treated with chemicals that form bonds between starch chains, making it more stable.
Does modified cornstarch contain gluten?
No, modified cornstarch does not contain gluten. The modification processes alter the starch’s molecular structure but do not introduce any gluten-containing ingredients. Cornstarch starts out as a gluten-free grain, and the manufacturing processes keep it that way.
Gluten is a protein composite found in wheat, barley, and rye. It provides elasticity and structure to products made from these grains. Pure cornstarch and modified cornstarch are naturally free of gluten-containing grains and do not acquire gluten during processing. They remain gluten-free.
Why does it matter if modified cornstarch contains gluten?
Avoiding gluten is critical for those with celiac disease or non-celiac gluten sensitivity. For these individuals, consuming gluten triggers an immune response that damages the small intestine and causes potentially serious health problems. Even tiny amounts of gluten can be problematic.
Cornstarch is commonly used as a thickener in gluten-free cooking since it does not contain problematic proteins. Confirming that modified versions are also gluten-free means people with gluten restrictions don’t have to avoid recipes made with modified cornstarch.
Evidence that modified cornstarch is gluten-free
There are several main pieces of evidence that clearly demonstrate modified cornstarch remains gluten-free:
- Reputable cornstarch manufacturers explicitly state their products are gluten-free, even after modification. This includes brands that specialize in gluten-free offerings.
- Third-party certification organizations, which test products for gluten down to trace levels, certify that modified cornstarches are gluten-free.
- Studies show modified cornstarches do not contain detectable levels of gluten. A process like pregelatinization does not introduce new protein content.
- People with celiac disease or gluten intolerance are able to consume modified cornstarch without ill effects.
Safety standards for labeling gluten-free foods
For a product to be labeled as “gluten-free” in the United States, it must contain less than 20 parts per million (ppm) of gluten as per the FDA’s gluten-free labeling law. Most people with celiac disease or non-celiac gluten sensitivity can tolerate levels below 10 ppm.
Manufacturers of modified cornstarch take careful precautions to avoid gluten cross-contamination and routinely test their products to ensure they fall well below the maximum gluten threshold to be legally considered gluten-free. Consumers can feel confident that items labeled gluten-free have been rigorously vetigated.
International labeling regulations
Other countries follow similar regulations:
- European Union – max 20 ppm gluten for “gluten-free” labeling
- Canada – max 20 ppm gluten for “gluten-free” labeling
- Australia/New Zealand – max 20 ppm gluten for “gluten-free” labeling
So modified cornstarch labeled gluten-free in other countries also remains below the internationally accepted cutoff.
Verification using independent lab testing
In addition to rigorous procedures by manufacturers, many brands of modified cornstarch have been tested independently in third-party laboratories to confirm gluten-free status. These labs use advanced methods like ELISA tests to detect traces of gluten down to 3 ppm or lower.
Across numerous published studies, tests supported that modified cornstarches from leading brands contained no detectable gluten proteins. This adds extra assurance that these products are truly gluten-free after modification.
Safety for gluten-free diets
Leading health organizations consider modified cornstarch safe for gluten-free diets when sourced from reputable suppliers:
- Celiac Disease Foundation – Includes modified cornstarch in gluten-free food lists
- Beyond Celiac – Confirms modified cornstarch is “inherently gluten-free“
- American Gastroenterological Association – Approves modified cornstarch use for people with gluten-related disorders
With proper sourcing and testing, there is an overwhelming consensus that modified cornstarch can be part of a gluten-free diet.
Sourcing reputable gluten-free cornstarches
While many major cornstarch brands produce gluten-free products, it is still smart to double check packaging or contact manufacturers directly if you have celiac disease, non-celiac gluten sensitivity, or other reasons to avoid gluten strictly.
Some transparent cornstarch brands include:
- Bob’s Red Mill: Tests all cornstarch below 5 ppm gluten
- Argo: States plain and modified cornstarches are gluten-free
- Cargill: Labels cornstarches gluten-free and made in dedicated facilities
Checking major gluten-free food blogs for updated cornstarch brand recommendations can also help identify options that consistently test free of gluten cross-contamination.
Uses of modified cornstarch in gluten-free cooking and baking
Modified starches perform better than plain starches in some gluten-free recipes, so they are very useful in gluten-free cooking. Here are some ways to use modified cornstarch:
- Sauces and gravies – Pregelatinized cornstarch or stabilized cornstarch blends can thicken liquids evenly without forming lumps.
- Gluten-free bread – Vital wheat gluten gives structure to regular bread, but xanthan gum and hydroxypropyl methylcellulose combined with pregelatinized cornstarch can create an elastic gluten-free bread dough.
- Gluten-free cakes – Cross-linked cornstarch maintains moisture in cakes for a light, tender crumb without gluten.
- Gluten-free pie fillings – Acid-hydrolyzed cornstarch thickens pie fillings properly through baking and refrigeration without weeping liquid.
With some recipe testing, modified cornstarches can help overcome many of the texture and moisture challenges of gluten-free baking. Thankfully, brands that labeling gluten-free status and proper sourcing ensure these modified starches are safe to use.
Bottom Line
Modified cornstarch does not contain any gluten. The modification processes only alter the starch’s molecular structure but do not introduce new protein content. Both cornstarch manufacturers and third-party certifications verify modified cornstarches remain gluten-free through stringent testing procedures. When sourced from reputable suppliers that avoid cross-contamination in facilities, modified cornstarch is safe for gluten-free diets.
