TBHQ

Abbreviation for tert-butylhydroquinone — a synthetic phenolic antioxidant used to protect unsaturated fats and oils against oxidative rancidity. TBHQ is particularly effective in frying oils, where its good heat stability and carry-through protect both the oil and the fried food during high-temperature use; it also stabilizes margarines, snack foods, and animal feeds. Like all food antioxidants, its use is limited by regulation to small proportions of the fat content (for example, 0.02% of fat in the United States), and it must be declared on labels. Excessive doses can show pro-oxidant or toxic effects, so good manufacturing practice keeps additions minimal.