ABSTRACT
In foods, antioxidants have been deŒned as “substances that in small quantities are abletopreventorgreatlyretardtheoxidationofeasilyoxidizablematerialssuchas fats”(Chipault,1962).Inbiologicalsystems,thedeŒnitionhasbeenextendedto“any substancethat,whenpresentatlowconcentrationscomparedtothoseofanoxidizablesubstrate,signiŒcantlydelaysorpreventsoxidationofthatsubstrate”(Halliwell
10.1 Introduction .................................................................................................. 185 10.2In Vivo ........................................................................................................... 186
10.2.1Antioxidant Defense System ............................................................. 186 10.2.2Enzymatic Antioxidants ................................................................... 186 10.2.3Nonenzymatic Antioxidant Proteins and Other Macromolecules .... 189 10.2.4 Nonenzymatic ROS Scavengers ....................................................... 189
10.2.4.1Hydrophilic ROS Scavengers ............................................. 189 10.2.4.2Hydrophobic ROS Scavengers ........................................... 190
10.3Metal Ion Chelators ...................................................................................... 191 10.4Other Actions of Antioxidants ...................................................................... 191 10.5 Antioxidants in Foods ................................................................................... 192
10.5.1Sources of Antioxidants .................................................................... 192 10.5.2Antioxidants Naturally Present in Foods ......................................... 192
10.5.2.1Food of Plant Origin .......................................................... 192 10.5.2.2Foods of Animal Origin .................................................... 196 10.5.2.3 Combining Meat and Fish with Vegetables ....................... 198
10.5.3Antioxidants Formed in Food during Processing ............................. 199 10.5.4Antioxidants Added to Foods ...........................................................200 10.5.5Designer Foods with Antioxidants ................................................... 201
10.6Methods for Determination of Antioxidant Activity ....................................202 10.6.1 Antioxidant Assays ...........................................................................202 10.6.2HAT-Based Methods ........................................................................202 10.6.3SET Mechanism-Based Methods .....................................................203 10.6.4Other Methods ..................................................................................204
10.7Final Remarks ...............................................................................................205 References ..............................................................................................................206
