Characterization of starch from two ecotypes of andean achira roots (Canna edulis)

Starches from two ecotypes of achira roots (Canna edulis Ker-Gawler) were characterized and compared to commercial potato and corn starches. This included scanning electron microscopy (SEM) of starch granules and amylose content determination of starch. Starch solutions or gels were tested by rotational viscometry, Rapid Visco Analyzer (RVA), and texture analysis. Some starch samples were subjected to various treatments: pH reduction, autoclaving at high temperature, and high shear before testing by rotational viscometry. Achira starch showed some unusual properties, such as very large oblong granules (∼45-52 μm major axis and ∼33-34 μm minor axis) and relatively high amylose content (∼33-39%). The San Gabán achira ecotype formed highconsistency gels upon cooling, both in RVA study (5% starch) and in texture analysis (8% starch), compared to other starch gels and also exhibited higher thermal resistance to viscosity breakdown. © 2009 American Chemical Society.