Further reading - Food processing Fruits vegetables and roots KnO 100192_Cassava

Cassava processing

Practical Action

The essential ingredients in starch-based adhesives are starch/flour, gelatinisation modifier

sodium hydroxide (NaOH), viscosity enhancer/stabiliser (borax) and preservative (sodium

formaldehyde). The amount of borax and NaOH must be determined experimentally so as to

produce the correct viscosity and pasting temperature to meet the requirements.

Ethanol

The fermentation of converted starch can produce ethanol, a basic alcohol. The process is not

new and has been used in food and pharmaceutical products over the years. Now there is renewed

interest in ethanol as a bio-fuel as it can reduce overall CO2 emissions. It has the potential to

provide economic development to rural areas by improving fuel access, as well reducing

dependency on imported fossil fuels.

Small-scale ethanol production plants have been developed which can produce approximately

4000 litres/day of alcohol at 96% depending on the model.

The plant will need good water supply and continuous electrical supply (around 50Kva). The plant

will also produce around 2-3m3/hr of effluent. This has to be disposed of properly and is normally

used as an animal feed.

Bio-degradable packaging

Kasetsart University (Bangkok, Thailand) has developed a bio-degradable cassava starch based

packaging material that can be made into a variety of shaped products. These can be used in

place of fossil fuel based plastics products. The material is low cost, easily processed,

biodegradable and can be made from agricultural surplus raw materials.

Quality control

For commercial enterprises quality and consistency of the product becomes important, especially

when considering export markets. Careful monitoring of the composition of the raw material and

the properties of the finished products is required. Quality control should be incorporated in to

the production process. The two most important ingredients in processing are the cassava roots

and the water used.

A simple method of ensuring a consistent standard of quality is to undertake small-scale

processing trials to compare the product with standard samples. When cassava is used as food it

is important to test for the presence of hydrocyanic acid. Analysis of commercial starches is

becoming more important in the commercial setting. Standards and methods of analysis for

starch and its products have been issued by the International Organization for Standardization.