Starch

Food · Pantry & Condiment · Food, Typed Supps

Not a flour. Starch is the one part of the plant left after everything else is washed away.

Stage by stage

Intake (Inert until cooked): Dry granules are tasteless and indigestible until heat and water gelatinise them.
Digestion (Amylase acts fast): With no protein matrix to slow it, gelatinised starch is cleaved to glucose very efficiently.
Absorption (High glycaemic response): Glucose enters the blood rapidly — cooked isolated starch sits at the top of the GI range.
Large bowel (Resistant fractions fermented): Raw granules (RS2) and cooked-then-cooled starch (RS3) reach the colon and are fermented to short-chain fatty acids.

Time to effect

Under an hour, or a day: Cooked starch peaks blood glucose within about 30 minutes; the resistant fraction ferments over 12 to 24 hours.

Allergens

None of the fourteen major allergens. Derived from what this food is, not from a product label.

Eating patterns

Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Gluten-free. Depends on the product: Low-FODMAP.

Satiety

Not scored: the satiety index is measured on 240 kcal servings, and nobody eats a 240 kcal serving of this. The question does not apply rather than the answer being unknown.

Cost band

Mid — roughly £5 per kg, as a band midpoint rather than a price.

Key nutrients

Carbohydrate
Resistant starch

Nutrition per 100g

Calories: 318
Protein: 0g
Carbohydrate: 74.5g
of which sugars: 0g
Fat: 0.5g
of which saturated: 0.2g
Fibre: 5.9g
Sodium: 9mg

Food vs. supplement

Raw potato starch is the leading resistant-starch supplement and the claim is mechanistically sound — but only while it stays raw. Cooked into a sauce it is ordinary, rapidly digested starch.

Kitchen tip

Slurry in cold water first. It gelatinises around 60–65°C, thickens clear, and breaks down if boiled hard or held in acid — use cornflour or arrowroot for long or acidic cooking.

Common myth

“Potato starch and potato flour are interchangeable.” In reality: Potato flour is dried whole potato and still contains protein and fibre; potato starch is the washed, isolated granule and contains neither. They behave differently in a batter, thicken differently, and are not substitutable by weight.

In the glossary

Blood sugar