1). Physical-morphological properties
Cassava or often known as the popular name of cassava, is a multi-use plant, from sweet potatoes to leaves can be utilized. Juicy as the main source of carbohydrates and leaves as vegetables. In general, cassava is shaped like a cylinder whose tip is smaller with an average diameter of about 2 – 5 cm and a length of about 20-30 cm. Umbinya has a skin consisting of 2 layers, the outer skin is brown and the skin inside is reddish or white. Tuber meat is white or yellow. In the center of tuber meat there is a network composed of fibers. Between the inner skin and tuber meat is a layer of cambium. These tubers have long stems and some are not stemmed.
Figure 2.10. Cassava ( Manihot esculenta L. Crantz)
The physical-morphological properties of several varieties of cassava are presented in the table
2). Nature of Cassava Chemical
Cassava contains a lot of fresh water and starch. The complete chemical composition of cassava can be seen in the table below.
Cassava contains a toxin called cyanide acid (HCN). Based on their cyanide acid content, cassava can be classified into four (a) non-toxic groups containing 50 mg HCN per kg of freshly shredded bulk, (b) slightly toxic with HCN between 50 and 80 mg per kg, (c) toxic, containing HCN between 80 and 100 mg per kg and (d) highly toxic, containing HCN greater than 100 mg per kg.
Non-toxic cassava is known as cassava while the poisonous cassava is called bitter cassava. Some varieties of cassava such as Valenca, Ivory and W 78, while varieties SPP, Wara, Bogor and W 236 including bitter cassava. HCN levels in some cassava Types or varieties were presented in Table 2.9. Cassava with high HCN content can be used in the industry of cassava starch, because during the soaking and washing process, this HCN level will decrease. This is due to the water-soluble nature of HCN.
Table 2.9. Important properties of several types or varieties of Cassava
