Page 104 - Natural Antioxidants, Applications in Foods of Animal Origin

Natural Antioxidants: Occurrence and Their Role in Food Preservation 83
VetBooks.ir or less, so that the effect of their rancidification may be masked by other,

sensorily more active substances. Fruits contain natural essential oils, which
possess antioxidant activities but are also easily oxidized. They are protected
by similar antioxidants as glyceridic oils. If lipoxygenases are deactivated
by blanching, the content of natural antioxidants (mostly flavonoids) would
be sufficient to protect the lipid fraction against oxidation. Natural antioxi-
dants are applied only exceptionally, for example to protect carotenoids or
anthocyanins against oxidation. Pigmented orange juice was stabilized with
AA and phenolic acids and pasteurized (Maccarone et al., 1988; Pokorný &
Trojáková, 2001). The use of natural antioxidants is more justified for the
stabilization of dried products. The stability of dehydrated mashed potatoes
was achieved with α-T or ascorbyl palmitate or with Prolong P (a mixture
of rosemary, thyme, and marjoram) with more success than with TBHQ
(Baardseth, 1989; Pokorný & Trojáková, 2001).
The application of synthetic antioxidants will probably be reduced
further. They could be replaced by natural or nature-identical antioxidants.
We believe that only few more new natural antioxidants will be introduced
to the market in the near future in addition to the rosemary extract currently
being used. Green tea extracts (prepared from dust, old leaves, and other
tea wastes) also have a fair prospect of market success. Tocopherols and
β-carotene will probably be increasingly used. Prolongation of the shelf life
of complex foods will be achieved mainly by modifying recipes, introducing
herbs and spices with a high concentration of natural antioxidants, using
high-oleic edible oils requiring lower antioxidant levels and using protein
hydrolysates, which act as good synergists.

2.17 REGULATORY STATUS OF NATURAL ANTIOXIDANT
EXTRACTS, CONCENTRATES, AND RESINS

Synthetic antioxidants (BHA, BHT, PG, TBHQ, and EDTA) are regulated
by the FDA as direct food additives. They may be used alone or in combina-
tion not to exceed 0.02% (200 ppm) of the final product in specified food
products (21CFR172.110). These antioxidants are considered to be safe and
suitable ingredients for use in meat, poultry, and egg products, alone or in
combination, not to exceed 0.02% of the fat content (FSIS Directive 7120.1.
revision 5). Some herbs, spice extracts, and oleoresins are GRAS. Some
are considered to be indirect additives (21 CFR Vol. 3. Part 101); as such,
solvents permitted for the extraction process and solvent residues allowed are
specified. Some extracts, concentrates, and resins are regulated by the FDA