TOWARD IMPROVED CASSAVA PROCESSING: INVESTIGATING PHYSICAL PROPERTIES OF BRAZILIAN CASSAVA ROOTS

In some countries, cassava (Manihot esculenta Crantz) processing often takes place in equipment designed for other crops. This results in a starch extraction yield of less than 30%. To improve this yield, it is necessary to develop more efficient equipment, which requires information about the engineering properties of the root, including its physical characteristics. This data is crucial for designing more effective cassava processing, handling, and harvesting equipment, also affecting the culinary quality of the products. In light of this, this study aimed to determine various physical properties of cassava roots grown in Brazil, including total mass, length, and head, middle, and tail diameter, pulp, bark, and skin yield, as well as skin thickness (in all three parts) and xylem. Geometric shape was also observed. For this purpose, 30 samples of freshly harvested cassava from Barreiras-BA and Campinas-SP were used. The results revealed that the total mass of the roots varied significantly, ranging from 119 to 1548 g, with the pulp representing the majority (76.9±7.1%), followed by the bark (13.6±3.0%) and skin (2.6±1.3%). The length varied from 9.8 to 48.9 cm, similar to Nigerian cultivars. As for the total diameter, the roots had 4.2±1.1 cm for the head, 5.0±2.8 cm (middle), and 2.2±1.0 cm (tail). The skin thickness was very thin (head: 0.8±0.5 mm, middle: 1.0±0.5 mm, and tail: 0.6±0.4 mm), making manual peeling difficult and requiring sophisticated equipment to prevent losses. On the other hand, the xylem, where starch accumulates and can contain poisonous cyanide, had a thickness of 1.5±0.7 mm. The predominant shape was oval, although cassava tends to have irregular shapes. In summary, it is evident that cassavas exhibit high variation in their physical aspects, emphasizing the need for equipment design that takes this diversity into account.