Magnesium stearate is a fine white powder that sticks to your skin and is greasy to the touch. It’s a simple salt made up of two substances, a saturated fat called stearic acid and the mineral magnesium. Stearic acid can also be found in many foods, such as:

chicken
eggs
cheese
chocolate
walnuts
salmon
cotton seed oil
palm oil
coconut oil

http://www.chinafooding.com/Magnesium_Stearate