Characterization of cassava starch attributes of different genotypes

The genetic variation of starch of Indonesian cassava genotypes with various morphological characteristics of roots and eco-geographical origin was characterized and compared. The morphological characteristics of the roots of 71 collected cassava genotypes were classified into yellow and white for flesh colors, purple, pink, light brown, yellow, cream and white for cortex colors, dark brown and light brown for external colors, as well as conical and cylindrical for root shapes. Starch samples extracted from 17 genotypes showed that the amylose content varied from 17.1 to 21.3%. The mean particle size was around 7.3 to 9.7 mu m, and the gelatinization onset temperature was in the range of 63.5-66.1 degrees C. Seven genotypes were analyzed in more detail for their physicochemical properties. The granule size distribution was in the range of 3.2 mu m to 17.6 mu m for d10 and d90 (i.e. 90% of the granules were bigger than 3.2 pm and 90% were smaller than 17.6 mu m), respectively, and the median granule size was around 7.7-10.8 mu m. The gelatinization temperatures of the different cassava starches were in the range of 63.5-66.1 degrees C. The phosphate content varied from 23.5-25.3 nmol/mg starch. Particle size distribution and gelatinization temperature as well as the phosphate content of the starch of the selected seven genotypes also showed minor differences among the genotypes. The swelling power of all starches showed some differences between genotypes, but the profiles were similar. The opacity of starch of all the tested genotypes increased twofold within six days, but no large differences among the different genotypes could be detected except for the genotype Ketan. Strength of the gels, which are indicated with force, adhesiveness, cohesiveness, and elasticity, also did not show large differences