Antioxidants and Shelf Life of Foods - Food Shelf Life Stability: Chemical, Biochemical, and Microbiological Changes - page 175

Food Antioxidants

Primary Secondary Synergistic

Oxygen Scavengers
Sulfites
Ascorbic Acid
Ascorbyl Palmitate
Erythorbic Acid

Thiopropionic Acid (TDPA)
Dilauryl and Distearyl
Esters of TDPA

Phenols
Gallates
Hydroquinone
Trihydroxybutyrophenone
Nordihydroguairetic Acid

Chelating Agents
Polyphosphates
EDTA
Tartaric Acid
Citric Acid
Phytic Acid
Lecithin

"Hindered" Phenols
BHA
BHT
TBHQ
Tocopherols
Tocotrienols
Plastochromanols
Gum Guaiac
Ionox Series

Miscellaneous

Nitrates
Amino Acids
Spice Extracts
Flavonoids
Carotenoids
Tea Extracts
Zinc
Selenium
Lignans
Ascorbate
Processing-
Antioxidants

Miscellaneous

Ethoxyquin
Anoxomer
Trolox-C
Flavonoids
Herbs Extracts
Spices Extracts
Carotenoids
Lignans
Ascorbate
Processing-
Antioxidants

FIGURE 6.2 Types of food antioxidants.

of primary antioxidants by acting as hydrogen donors to their radicals, thereby
regenerating the primary antioxidants or inactivating metal ions. 16

B IOLOGICAL A NTIOXIDANTS

Natural antioxidants are present in the body to protect cells from excessive oxidation
and free-radical damage. These include metalloenzymes which can interfere with
the production of free radicals during the initiation phase, such as superoxide dis-
mutase which contains Mn or Cu/Zn (see Chapter 10) or catalase which contains
Fe and glutathione peroxidase which contains SE. The latter is important in the
decomposition of hydrogen peroxide and lipid hydroperoxides. 17
Three essential nutrients can directly interfere with the propagation stage to
scavenge free radicals. Of these, -tocopherol is the major lipid-soluble antioxidant

present in all cellular membranes. Vitamin C or ascorbic acid, the major water-
soluble antioxidant, is capable of quenching free radicals and singlet oxygen, as

α