<P> If starch is subjected to dry heat, it breaks down to form dextrins, also called "pyrodextrins" in this context . This break down process is known as dextrinization . (Pyro) dextrins are mainly yellow to brown in color and dextrinization is partially responsible for the browning of toasted bread . </P> <P> A triiodide (I) solution formed by mixing iodine and iodide (usually from potassium iodide) is used to test for starch; a dark blue color indicates the presence of starch . The details of this reaction are not yet fully known, but it is thought that the iodine (I and I ions) fit inside the coils of amylose, the charge transfers between the iodine and the starch, and the energy level spacings in the resulting complex correspond to the absorption spectrum in the visible light region . The strength of the resulting blue color depends on the amount of amylose present . Waxy starches with little or no amylose present will color red . Benedict's test and Fehling's test is also done to indicate the presence of starch . </P> <P> Starch indicator solution consisting of water, starch and iodide is often used in redox titrations: in the presence of an oxidizing agent the solution turns blue, in the presence of reducing agent the blue color disappears because triiodide (I) ions break up into three iodide ions, disassembling the starch - iodine complex . A 0.3% w / w solution is the standard concentration for a starch indicator . It is made by adding 3 grams of soluble starch to 1 liter of heated water; the solution is cooled before use (starch - iodine complex becomes unstable at temperatures above 35 ° C). </P> <P> Each species of plant has a unique type of starch granules in granular size, shape and crystallization pattern . Under the microscope, starch grains stained with iodine illuminated from behind with polarized light show a distinctive Maltese cross effect (also known as extinction cross and birefringence). </P>

Where is the most starch found in the plant cell