Diets
thermal bran stabilization decreases total dietary fiber
In plain terms: Does heat-treating bran destroy its fibre?
Mostly no. Heating or processing bran tends to CONVERT its rough insoluble fibre into the soluble kind rather than destroy it — total fibre is usually preserved or only slightly reduced. Contested, and based on lab food-chemistry, not health outcomes.
📅 Last reviewed: 2026-07-15 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Cells in a dish (In-vitro)
How the studies fall
What the evidence shows
The claim that thermal stabilization lowers total dietary fibre (TDF) leans against on current evidence. Solmaz found TDF fell in all stabilized cookies (autoclave lowest), but independent higher-quality work disagrees: Özkaya found autoclaving oat bran increased soluble, insoluble and total fibre, and Martín-Cabrejas found extrusion left TDF unchanged — merely redistributing…
The evidence (4)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Solmaz B, Levent H, Şahin N 2025 · Food Science & Nutrition | in-vitro | supports | moderate | Cookie Table 3 TDF % by method: raw 15.68a, hot air 14.67ab, microwave 14.52ab, autoclave 12.78b (control 9.43). All point estimates fall, but only autoclave differs significantly from raw by the letters; hot air and microwave do not. Authors attribute the fall to glycosidic-bond cleavage / arabinoxylan loss. Measured in 20%-bran cookies. |
| Ozkaya et al. 2017 · J Agric Food Chem | in-vitro | contradicts | high | Autoclaving oat bran INCREASED soluble, insoluble AND total dietary fibre vs control - opposite of a TDF reduction. |
| Tian XY, Liu JF, Cheng Z, Wu NN, Tan B 2024 · Food Res Int | in-vitro | tested-null | low | Steam explosion of rice bran degraded IDF cellulose/hemicellulose (glycosidic bonds broken) - structural degradation of extracted IDF; net TDF mass not reported; harsher than stabilization. |
| Martín-Cabrejas MA, Jaime L, Karanja C, Downie AJ, Parker ML, Lopez-Andreu FJ, Maina G, Esteban RM, Smith AC, Waldron KW 1999 · J Agric Food Chem | in-vitro | contradicts | low | Extrusion of beans redistributed insoluble->soluble fibre but TOTAL dietary fibre was unaffected (legume/extrusion, off-method). |
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