Production of very-high-amylose potato starch by inhibition of SBE A and B

High-amylose starch is in great demand by the starch industry for its uniqu e functional properties. However, very few high-amylose crop varieties are commercially available. In this paper we describe the generation of very-hi gh-amylose potato starch by genetic modification. We achieved this by simul taneously inhibiting two isoforms of starch branching enzyme to below 1% of the wild-type activities. Starch granule morphology and composition were n oticeably altered. Normal, high-molecular-weight amylopectin was absent, wh ereas the amylose content was increased to levels comparable to the highest commercially available maize starches. In addition, the phosphorus content of the starch was increased more than fivefold. This unique starch, with i ts high amylose, low amylopectin, and high phosphorus levels, offers novel properties for food and industrial applications.