Irregular culinary quality of cassava roots has been one of the major point that restricts its expansion for human consumption. A good quality cassava root, after cooking and smashing with a fork, results in a no stick mass, quite plastic and without grooms. Cooking time is closely related to the quality of the cooked mass, i.e., the shorter it takes to cook, the better the mass produced. Therefore, in this work, the duration of cooking time (DCT) was used as an express method for evaluating culinary quality of cassava roots. Variations in DCT may be related to two group of factors: a) intrinsic - which takes into account within the root variability, root to root, as well as differences among plants of the same variety; b) extrinsic - which considers the effects of plant genotype, environmental conditions and physiological phase of the plant. The main objective of this work is to verify and quantify how DCT was affected by the described factors. Preliminary studies were performed under field conditions at Instituto Agronômico, Campinas, State of Sao Paulo, Brazil, using five contrasting cultivars grown up in two different soil types. Root samples were taken monthly from the 7th to the 15th month after planting. DCT was determined with sub-samples of each root of the plant and starting of cooking time was considered at the moment in which roots were immersed in the boiling water. Results indicate that: a) average DCT decreased 12 min from the base to the tip of the root; b) within the same plant, DTC varied from 11, 10 and 27 min at the age of 8, 12 and 15 months respectively; c) difference among cultivars harvested with the age of 7-15 months was 9 min and when soil type was included in the analyses it reached 17 min; d) lowest DCT was observed for harvestings between 7-12 months after planting.
sweet cassava; varieties; cooking time; culinary quality