Physicochemical Properties and the Digestibility of Cassava Root and Stem Starches Associated with Genotypes

Abstract

Cassava stems contain up to 40% starch (by dry mass) and are currently discarded as agricultural waste. The current study aims to understand the physicochemical traits of cassava stem and root starches for investigating trends in industrial cassava applications. In total, 11 traits of both cassava stem and root starches of 15 genotypes are investigated. All the examined traits of cassava root and stem starches vary by genotype. The amylose contents of root and stem starches are in the range of 19.0-33.0% and 18.44-34.51%, respectively. The resistant starch of root and stem starches are in the range of 1.72-17.72% and 4.42-13.37%, respectively. Only the starch content, solubility, and swelling power of root starches are significantly higher than those of stem starches. The root starch gel is more stable than the stem starch gel after the fourth and fifth freeze-thaw cycles. Furthermore, principal component analysis calculated based on starch and amylose contents, degree of swelling, digestibility, and freeze-thaw stability demonstrates that genotypes GW46, GW88, S1, E26, and GC49 gain higher scores than control varieties South China 12 and South China 205, which are the most favorable ones by farmers in China because of good root yields.