Texture analysis of raw and cooked tubers of short‐duration lines of cassava by multivariate and fractional conversion techniques

BACKGROUND: Cassava tubers are mainly consumed after boiling in water. Their cooking quality depends on the variety, maturity, growing conditions and physicochemical and starch properties. In this study the textural and gelatinisation characteristics of ten short‐duration lines of cassava were assessed. Textural changes due to cooking were modelled by fractional conversion techniques and correlated with gelatinisation and physicochemical properties by principal component analysis. RESULTS: There was a significant variation (P < 0.05) in the textural properties of tubers and the thermal and pasting properties of flours among varieties. The degree of cooking and relative firmness of tubers were modelled by a linear equation. The thermal softening behaviour was modelled by a dual‐mechanism first‐order kinetic model with rate constant values ranging from 0.106 to 0.190 min^?1. About 69.21% of the total variation in texture profile, gelatinisation and physicochemical parameters could be explained by the first three principal components. CONCLUSION: The results indicated that the textural and gelatinisation properties varied considerably among different varieties. However, the interaction between the components of the tubers and the structural make‐up of the tuber tissues played a more important role than the physicochemical and functional properties. Copyright © 2008 Society of Chemical Industry