cassava flour processing pdf

cassava flour processing pdf how to produce cassava flour

To produce cassava flour, first wash the fresh roots then peel them. Wash the peeled roots. The roots are then chopped into small pieces about 5 x 0.5 x 0.2 cm, and sun-dried for two or three days (or dried in a hot air oven at 55oC). After drying, the moisture content of the cassava chips should be less than 8%.

The chips are then milled, and the flour sieved through an 80 mesh sieve. Finally, the flour is packaged in plastic bags. Packaged in this way, the flour can be stored for at least eight months. The yield recovery of flour is about 20 - 40%, depending on the cultivar, the time of harvest and the equipment used.

cassava flour processing

Avoiding Toxicity Problems

Good-quality cassava flour should be white and have a good smell. It should not be contaminated by insects or undesirable microorganisms. If drying takes place outdoors, this should be done on sunny days, otherwise the chips may smell bad and turn brown.

It is best to use cassava cultivars which contain a low level of cyanogenic compounds, since these are potentially toxic. However, the cyanogenic content of fresh roots is not a serious problem in cassava flour production, since it is almost entirely eliminated during flour processing. Furthermore, Thailand's traditional cassava cultivars do not contain a high level of hydrocyanic acid. Our experiments on dried chips of cassava from nine cultivars found that the hydrocyanic content fell from 13.5-114.7 ppm in the fresh roots to 0.40- 2.37 ppm in the flour. The level varied according to the cultivar and the time of harvest.

To produce cassava flour, first wash the fresh roots then peel them. Wash the peeled roots. The roots are then chopped into small pieces about 5 x 0.5 x 0.2 cm, and sun-dried for two or three days (or dried in a hot air oven at 55oC). After drying, the moisture content of the cassava chips should be less than 8%.

PRODUCTION PROCESS

The basic unit operations in cassava flour production from fresh cassava roots are:

Sorting and Weighing: The tubers are sorted to select the wholesome roots for production. The tubers are then weighed.

Peeling: The weighed cassava roots are peeled manually to reduce high peeling loss associated with mechanical peelers due to irregular shape of cassava root.

Washing: Peeled root is washed with sufficient quantity of potable water to remove sand, dirt and other contaminants.

Grating: The root is grated to cassava mash.

Detoxification: The cassava mash is detoxified mechanically in a mash agitator for a period of time to eliminate the toxic hydrogen cyanide present in cassava.

Dewatering: The moisture content of the mash is reduced mechanically to about 50% to prepare for drying operation.

Granulation: The resultant cake from dewatering process is disintegrated into fine granules using hammer mill.

Drying: Granulation process is followed by drying operation to produce cassava flour of desired quality.

Milling: The flour obtained is milled to desired particle size.

Sieving and Packaging: The flour is sieved and packaged appropriately.

cassava flour processing pdf how to produce cassava flour