In the Jewish religion, how is food preparation regulated?
Jewish food preparation, called Kashrut, is regulated according to principles and rules laid out in the Mishna, which codified Jewish law. Since food is no longer grown and prepared at home in much of the world, regulatory groups were formed to ensure that mass-produced food items are prepared within these laws and boundaries. These groups are privately-owned and operated, and are not connected with the FDA or other government institutions; their major work is to observe food preparation procedures and authorize the use of a trademarked symbol to differentiate kosher food from non-kosher food. A common misconception is that these symbols represent a "kosher tax" which is charged to both producers and consumers to support Zionist agendas; organizations do charge for their service, but it is entirely for the endorsement of the food product according to kosher standards.
The largest of these groups is the Orthodox Union, which oversees almost half-a-million products worldwide. Workers who visit factories and plants to examine procedures are called Mashgiachs, and are both ordained and non-ordained. There is no interference with the food production itself, just observation; if kosher standards are not met, the food is not endorsed. Kashrut organizations have no power to change or enforce their standards; following those standards is entirely up to the food producers themselves. If a food producer stops employing a kashrut organization, the kosher symbol is removed and production continues. Some organizations are more "acceptable" than others, depending on the consumer's level of orthodoxy.