Page 173 - Natural Antioxidants, Applications in Foods of Animal Origin

152 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir sources of natural antioxidants. Phenols, polyphenolics, and phenolic acid

derivatives are antioxidants common to all plant sources of natural anti-
oxidants. Furthermore, modified proteins and amino acids are antioxidants
derived from animal and microbial products. The various sources of natural
antioxidants are cereals (whole wheat products, oat, rice, bran), vegetables
(leaf vegetables, potatoes), fruits (apples, bananas, berries, olives), oilseeds
(sesame seeds, hazelnuts, almonds), legumes (beans, peanuts, soybeans),
cocoa products (chocolate), beverages (tea, coffee, red wine, beer, fruit
juices), and herbs and spices (rosemary, sage, oregano, savory).

4.4.2.1 ANIMAL ORIGIN

Amino acids, peptides, and carotenoids are three animal products that could
serve as natural antioxidants. Glutathione peroxidase, superoxide dismutase,
and catalase are antioxidant enzymes present in muscle systems. Anserine,
carnosine, and ophidine are histidine-containing dipeptides reported to
chelate metals and scavenge radicals(Chan et al., 1994). L-Histidine as part

of a small peptide/protein or in the free form can scavenge hydroxyl radi-
cals and quench singlet oxygen, which can react with the double bond of
L-histidine to form a peroxyl radical (Wade & Tucker, 1998). L-Histidine

has the ability to quench singlet oxygen three-fold higher than tryptophan
and five-fold higher than methionine.
Carotenoids typically associated with the color of fruits and vegetables
are also found in many animals. Crustacea demonstrate a multitude of carot-
enoid pigments found in nature. According to Zagalsky et al. (1990), carot-

enoids of invertebrates are associated with protein in a complex defined as
carotenoprotein. The carotenoids present in the exoskeleton of crustaceans
may provide the best opportunity to develop natural antioxidants from
animal sources. Red crabs contain β-carotene and astaxanthin while blue
crabs contain 4-hydroxyechinenone, canthaxanthin, 3-hydroxycanthax-
anthin, echinenone, isocryptoxanthin, β-carotene, and astaxanthin. These
compounds are the most common and important pigments from animal
sources that serve as natural antioxidants although limited research have been
completed on the antioxidant activity of carotenoids in crustacean (Ramı ́ rez

et al., 2001). However, their activity would be expected to be similar to plant
carotenoids due to the structural similarities between plant and animal carot-
enoids. Development of extraction or concentration processes is required
for the production of adequate amount of natural antioxidants from animal
sources.