A glokkel is something dirty in food
A Glokkel is a name for all things that are found in food that does not belong in it. You buy a pack of cereals and when you unwrap it you will see a dead mouse. A dead mouse in the Corn flakes can be seen quickly and will not lead to immediate problems very quickly. It can also be a piece of plastic or some glass in a pack of custard, those are things you don't see and may accidentally eat. Grokkels are for the person who eats it potentially dangerous, for the company responsible for the Grokkel it is also harmful. Think of damage claims, reputation damage or disappointing sales. A glokkelmeldpunt has been set up to map out how large the size of glokkels is.