The objective of this work was to evaluate the adequacy of instrumental texture analyses as a quality index for cassava roots for direct consumption, and the correlation with cooking time. Fifteen cassava roots were harvested in the eleventh month of growth in the northwest of the State of Rio de Janeiro. Pieces of roots were boiled in water and the cooking time determined in triplicate, to the point where there was little resistance to penetration by a fork. The shear strength was determined in the raw and cooked pulps with five to nine replicates, using the texturometer TA-XT Plus Texture Analyser with the Warner-Bratzler Blade HDP / BSW probe, a pre-test speed of 0.2 cm/s, post-test and test speed of 0.5 cm/s and distance of 5 cm. The data were analyzed by ANOVA and Tukey (cooking time), GLM, LSMEANS and PDIFF (shear resistance) and Pearson's correlation analysis (p < 0.05). The variety Viçosa Martinha stood out due to its shorter cooking time (18 minutes) and lower shear resistance values for the raw (10.6 N) and cooked (0.7 N) pulps. With the exception of the varieties Aipim Pretinho, IAC 13 and IAC Espeto, all the others could be considered suitable for direct consumption since they presented cooking times equal or below 30 minutes. There was significant correlation between the shear strength of the cooked pulp and the cooking time (0.62), although moderated by the high values obtained for the coefficient of variation of the texture measurements, highlighting the heterogeneity of the roots. Thus the determination of the cooking time under the experimental conditions used here is more suitable as a quality index of cassava roots associated with the texture.
Manihot esculenta; Cooking; Shear resistance; Instrumental measurement
