run something into something. 1. to guide or route something, such as a wire or a pipe, into something or a place. The worker ran the circuit into each room. He ran in the circuit as specified. 2. to guide something into something; to drive or steer something into something else.
A change of color to a blue-black or purple color suggests that starch is present. If there is no change in color, this suggests no starch is detectable. Note the change of the iodine to black on the potato (right) but not the apple (left). (10% Tincture of iodine.) Potato contains starch, but apple does not.
Once all the ascorbic acid has been oxidised, the excess iodine is free to react with the starch indicator, forming the blue-black starch-iodine complex. This is the endpoint of the titration. The method is suitable for use with Vitamin C tablets, fresh or packaged fruit juices and solid fruits and vegetables.