French Fries: Why soak in cold water, and if so, why a long time
The reason why you want to get rid of the excess starch on the surface is, while cooking they will brown faster and will yield very dark brown fries, instead of golden-brown "which we all like ;)". It has nothing (or little) to do with enzymes aiding caramelization/maillard reaction. The browning happens at high temperatures, such as the temperature of the frying oil. As you have more starches on the surface, they will get darker, or even burnt.

As a side note, I’ve found out that instead of soaking, just cooking the fries in water for a short while helps greatly in getting rid of the surface starches, even more than soaking or running them through water.