Effect of Maturity & Storage on Distribution of Phosphorus Among Starch & Other Components of Potato Tuber

Properties of Starch Obtained from Potato Tubers Influenced by Various Temperatures

“…Starch separated from the tubers stored at 0°C contained less amylose and phosphorus and showed higher reducing power than starch separated from the tubers before storage. A decreased amount of phosphorus in starch during potato storage at 0°C was also observed by Sumotus and Sckwimmer [9]. Changes in starch granularity developed during potato storage at 0°C were analogous to the changes in starch granularity observed during potato storage at + 20 "C.…”

“…Chemical composition and physical properties of potato starch depend on potato variety, vegetation conditions (soil, climate, meteorological conditions), period of planting and harvesting (length of vegetative season), fertilization and application of chemicals for plant protection. As many reports indicate, changes in granularity [l, 2, 31, amylose [4,5,6,7], phosphorus [6,8,9], calcium and potassium contents [S] in starch during potato storage have been the subject of numerous studies. However, the results of the studies are often inconsistent and incomparable because experiments have been performed on different materials and under various storage conditions (temperature and time of storage), and analytical methods have not been uniform.…”

Characterization of Solanum tuberosum Multicystatin and Its Structural comparison with Other Cystatins

“…Potato starch is phosphorylated, and this, along with synthesis of other P-containing carbohydrates, lipids, proteins, and nucleic acids during this metabolically active growth phase, results in relatively low levels of Pi in the cytosol of young, developing tuber cells (Samotus and Schwimmer, 1962b). A relatively low level of cytosolic Pi favors the monomeric (active) form of PMC, which in turn would inhibit Cys protease activity and thus facilitate protein synthesis and deposition in the developing tubers.…”

“…Moreover, in vitro studies have shown that proteolysis of patatin by tuber-derived Cys proteases is inhibited by PMC (Kumar et al, 1999). When tubers reach full size, synthesis of starch and other P-containing metabolites slows or ceases altogether as a sink for Pi, potentially effecting an increase in cytosolic Pi (Samotus and Schwimmer, 1962b) and favoring the crystalline inactive storage form of PMC, which is easily isolated from fully mature tubers at harvest (Rodis and Hoff, 1984).…”