ABSTRACT
Roots, tubers, and other plant parts utilize two fundamentally dierent strategies for the storage of carbohydrates in vegetative tissues, as an energy source. us, starch, sucrose, or other sucrose derivatives such as oligo-and
5.1 Introduction 105 5.2 History of Starch 106 5.3 Potato Starch 107
5.3.1 Production 107 5.3.2 Properties and Biochemistry 108
5.4 Structural Features of Potato Starch Granules 110 5.5 Starch Modication 110
5.5.1 Physical Modications 111 5.5.2 Chemical Modications 113
5.6 Amylases and Enzymatic Actions and Modications of Potato Starch 117 5.6.1 α-Amylases 118 5.6.2 β-Amylase 119 5.6.3 Glucoamylase 120 5.6.4 Cyclodextrin Glycosyltransferase 120 5.6.5 α-Glucanotransferases 121
5.7 Potato Starches, Diet, and Health 122 5.8 Perspectives and Conclusions 122 References 123
poly-fructosyl sucrose-also called fructo-oligosaccharides and fructans, respectively-are the major hydrocarbons involved in this process. In plants, these carbohydrates are metabolized in dierent ways. While sucrose and fructans (which are generally soluble) are synthesized and accumulated in vacuoles, starch (which is insoluble) is stored in plastids. In most species, starch is predominantly utilized for diurnal carbon storage in leaves, and studies have shown that the biosynthesis of starch is regulated to provide this energetic substrate for utilization through the dark period (Smith and Stitt 2007). Moreover, mechanisms controlling starch synthesis in heterotrophic sink tissues such as potato tubers have also been elucidated and are wellunderstood (Tiessen et al. 2002, 2003).
