E415: Xanthan Gum (Pseudoplastic Hydrocolloid Thickener)
Food Additives & E-Numbers · 7 specs
Direct Answer
Xanthan gum (E415) is a high-molecular-weight microbial exopolysaccharide produced by Xanthomonas campestris fermentation, renowned for extreme pseudoplastic shear-thinning rheology, freeze-thaw stability, and gluten-free dough structural binding.
Source: Codex Standard 192-1995 / EFSA ANS Panel (2017) / JECFA Monographs · Last reviewed Aug 28, 2026
Specs
| INS / E-Number | INS 415 / E415 |
| Polymer Structure | Cellulose β-(1,4)-D-glucan backbone with trisaccharide side chains (mannose-glucuronic acid-mannose) |
| Molecular Weight | 2.0 × 10⁶ to 5.0 × 10⁶ Da (2–5 MDa) |
| Rheological Behavior | Extreme Pseudoplasticity (Shear-thinning index n ≈ 0.15–0.25) |
| Yield Stress | High at rest (suspends dense particulates like herbs in salad dressing permanently) |
| Thermal Stability | Maintains constant viscosity from 0°C to 100°C across pH 2.0 to 12.0 |
| Synergistic Gelation | Forms thermo-reversible firm gels when blended with Locust Bean Gum (E410) or Guar Gum (E412) |
Pseudoplastic Shear-Thinning Flow Mechanics
At rest, rigid 5-fold helical xanthan polymer chains form an entangled network that creates a high yield stress, preventing oil droplets and dense spices from separating in salad dressings. Under shear force (shaking, pouring, or swallowing), the molecules align in the flow direction, dropping viscosity instantly by over 90% for smooth pouring.
Gluten Replacement in Gluten-Free Bakery Formulations
In gluten-free bread and pizza doughs lacking wheat gluten, adding 0.5% to 1.5% xanthan gum restores viscoelasticity, traps carbon dioxide bubbles generated by baker's yeast, prevents crumb collapse, and retains crumb moisture.