TBHQ, or tert-butylhydroquinone, is an organic, crystalline substance that is used as a preservative in many foods. It can be found as an additive in many unsaturated vegetable oils and in animal fats that are edible.
TBHQ is a powerful antioxidant that does not cause any change to the food that it is added to. Unlike other preservatives, TBHQ doesn't cause discoloration. It can also be combined with many other preservatives, and still not cause the food item to change in appearance or taste. TBHQ is also used for industrial purposes. In industry, it is used as a stabilizer during certain chemical reactions.