Cassava Starch is derived from the cassava tuber, It is a common ingredient used for food and industrial applications due to its versatile properties.
Cassava starch, also known as tapioca starch, is a white, powdery substance derived from the cassava root. It is a common ingredient used in various food and industrial applications due to its versatile properties. Here are some key points about cassava starch. It is extracted from the cassava tuber through a process that involves washing, crushing, and separating the starch from other components of the root. The starch is then dried and milled into a fine powder.
Cassava starch is produced primarily by the wet milking of fresh cassava roots. The roots contain about 28-30% starch and can be divided into:
- Food grade
- Industrial grade
- Other grades
There are other numerous applications like paint industry, cosmetics, chemical industry and bio plastics.
Researchers have recently discovered that thermo plastic properties of starch are favorable for bio plastic production. The bio degradability of starch-based plastics makes them very sustainable alternative to conventional petroleum-based plastics.
On the bases of applications/uses, it can be classified under:
- Food and beverages
- Pharmaceutical industry
- Paper industry
- Textile industry
- Other industry
Among the various cassava derivatives, starch is next to cassava chips in order of importance, applications at global trade. The applications of starch are wide and varied and some of them are:
The tubers are taken by a shoved loader out of the storage platform into the reception hopper install with electromagnetic vibrancy feeder at the bottom. After removing sand from the tubers, they are dropped into the belt conveyor where the stems, branches and woody tissues are manually cut off. There is squirrel type cleaner at the end of the conveyor that removes the sand and peels without water. They are then taken to the paddle washer where they are first soaked in fresh water and then agitated by the tubers rubbing each other thus the mud and the sand on them are cleaned off.
After washing the cleaned tubers are loaded on the inspection belt conveyor for second check and then sent to the rasping unit.
The tubers are first chopped into small pieces and then drop into the hopper in round shape with screw conveyors at the bottom. The screw conveys or with variable speed control then takes them into the rasper to be ground into cassava slurry. The screw conveyors are all frequency controlled to adjust feeding capacity. Process water is added to facilitate the rasping process;
What comes off the rasper is a mixture of free starch granules, fibres, combined starch, protein, sugar as well as mineral elements. The slurry flows down to the tank from where it is pumped to the cyclone de-sanding unit by the screw pump.
Rasping is used to break the starch granules in cassava tubers and reduces the combined starch content in the fiber.
The slurry enters the de-sanding cyclone at tangent under pressure. Due to the centrifugal force and the high-speed rotation, the light-phase particles in the slurry separate from the heavy-phase particles in the process, the light –phase particles such as starch and fiber will leave the de-sanding cyclone by overflowing from the top while the heavy-phase particles sink to the bottom and drop to the sand collecting pot which is supplied with upward water to avoid starch loss. The de-sand slurry will now enter the extraction unit.
The unit is made up of three-stage centrifugal sieves and one pulp dewatering sieve.
The cassava slurry from the de-sanding unit are pumped to the first centrifugal sieve where through the process of rotation the starch milk goes through the screen and pumped directly to the concentrating and washing unit. The cassava pulp screened out from this process are pumped by the fiber pump to the second-grade centrifugal sieve (recovering sieve) for recovering of starch and the fiber pulp coming from the first recovering sieve are pumped like waste to the third-grade centrifugal sieve for further recovering of starch.
After the third-grade extraction, there are almost no more starch in the fiber pulp. The fiber pulp is later sent to the dewatering unit. The starch milk extracted from both units are pumped to the processing water supplying unit for the first grade centrifugal sieve unit.
The starch milk from the centrifugal sieve is then pumped into the hydro cyclone unit for concentration, recovering and washing.
Robust screen design, optimum flushing design and special centrifugal sieves combination ensure that starch is maximally extracted from the pulp and reduces the free starch content to the zero level.