Sugar sweet colors

The beautiful colors we observe under the polarizing microscope have to do with the "optical activity" of - in this case - fructose.

Light is an electromagnetic wave phenomenon, in which the direction of vibration is perpendicular to the direction of propagation. An electric and a magnetic vector vibrate thereby at right angles relative to each other. In a 'normal' light, such as daylight, all directions of vibration are present at the same time. Polarized light, is light wherein only one direction of vibration in the beam is present.

Potatoes are everywhere

Potatoes contain starch in the form of typical large oval spherical granules; their size ranges between 5 and 100 microns. Under the microscope, the granules can be seen clearly in polarized light.

Potato starch – also known as potato flour – is extracted from potatoes. The cells of the root tubers of the potato plant contain starch granules (leucoplasts). To extract the starch, the potatoes are crushed and the starch grains are released from the cells. The starch is then washed out and dried to powder. Potato starch has been produced in the same basic way for centuries – actually even the ancient Incas knew how to make potato starch.