Starch and cellulose derivatives: Characteristics
Clear pastes or firm gels: what amylose decides
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Starch is sold on purity, moisture, viscosity and the ratio of amylose to amylopectin, which sets gel strength and clarity. Waxy maize and tapioca give clear, stable pastes; regular maize gives firm gels. Modification is tailored to the customer's process: paper mills want cationic charge, food makers want heat and freeze-thaw stability.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Moisture and purity | about 12-14% moisture; protein below 0.5% for maize starch (indicative) | Quality and yield in conversion | indicative |
| Amylose content | maize about 25-28%; waxy maize under 1%; tapioca about 17% (indicative) | Gel strength, clarity and stability | indicative |
| Degree of substitution (modified starch, CMC) | e.g. CMC DS 0.6-1.2 (indicative) | Sets solubility and viscosity | indicative |
Commercial grades
- Native maize, tapioca, wheat and potato starch
- Pregelatinised starch
- Oxidised and cationic starch (paper)
- Hydroxypropyl and cross-linked food starch
- Maltodextrin, glucose syrup, dextrose, sorbitol
- CMC, MC, HPMC, HEC