Technology assessment of small and medium cassava starch enterprises in North Vietnam

The cassava starch processing supply chain in Vietnam has rapidly changed over the past decade. The introduction of high yielding cassava varieties (KM 94, KM 60) with high starch content for industrial purposes has led to a complex situation, where both small and large scale producers have to tackle the burgeoning environmental issues. Three categories of small-sized wet starch extraction systems were identified in a cluster of root processing enterprises from the Red River Delta (Hoai Duc district, Ha Tay Province) where the hazards caused by liquid waste from cassava processing has been approved by all the stakeholders. The type A and B processors used cylindrical rasper with manual sieve (A) or a milk starch filtering machine (B); the type C processors used an equipment combining rasper and filtering machine. A methodology is proposed to assess the impact of these three technologies based on processing efficiency and volume of effluents. For each system, processing parameters such as dry matter, starch content, conversion rate, extraction efficiency and water consumption were studied. The amount of water used to produce one kg of dry starch, was 18, 14 and 22 l for systems A, B and C respectively. The quality of starch and byproducts and a cost estimation were also determined. Despite the growing popularity of the use of system C throughout the villages, it required higher power consumption than systems A and B. (Résumé d'auteur