Physicochemical and Functional Properties of Tropical Tuber Starches: A Review
Prev Page | Next Page- Introduction
- Extraction Techniques
- Other components in Starch
- Colour and Appearance
- Granule Shape and Size
- Spectral Features
- X-Ray Diffraction Pattern
- Molecular Weight
- Amylose Content
- Thermal Characteristics
- Gelatinisation and Pasting Temperatures
- Viscosity
- Swelling Power
- Solubility
- Clarity
- Sol stability
- Digestibility
- Conclusions
4. Colour and Appearance
Colour is an important criterion for starch quality, especially for use in sago and textile industries. The starch paste should be clear and free from any off-colour for better acceptability [20]. Starch from cassava tubers has a good white colour, if the skin and rind are removed prior to crushing [1, 68]. Chemicals like acids, sculpture dioxide, bleaching agents, etc. are occasionally used to improve the colour of starch, but these chemicals negatively affect the starch quality [69]. Organic acids also improve the colour at lower concentrations, but affect starch settling at higher concentrations. Use of ammonia could considerably improve the colour of the starch from aroids, especially Colocasia [8, 9]. Mechanisation of the starch extraction process, replacing the conventional method of drying in the sun and using centrifugal separation instead of settling tanks can improve colour and appearance of starch [68].
