Page 203 - Natural Antioxidants, Applications in Foods of Animal Origin

182 Natural Antioxidants: Applications in Foods of Animal Origin
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5.3.1.21 GRAPES

Grapes are used in various forms as seed extract, dietary fiber, pomace, grape
wine, etc. Grape seed extract (GSE) is already marketed as an ingredient
to the dietary supplementation industry, the quality and price of which are
based on its phenolic content. Phenolics in GSE exist as proanthocyanidins
in the form of oligomers and polymers of polyhydroxy flavan-3-ols such as
catechin and epicatechin (Weber et al., 2007). Antioxidant effect of GSE was
evaluated on cooked turkey patties and cooled stored turkey meat (Lau &
King, 2003). Grape pomace, a concentrate of grape seeds, stems, and peel, is
a rich source of flavonoids including monomeric phenolic compounds such
as catechins, epicatechin, and epicatechin-3-O-gallate and dimeric, trimeric,
and tetrameric procyanidins. It is used as dietary supplement to increase
antioxidant capacity in breast and thigh meat of broiler chickens (Ayerdi et
al., 2009).
Grape antioxidant dietary fiber (GADF) was effectively used at 0.5, 1,
1.5, and 2% concentration in raw and cooked chicken breast hamburger.
GADF addition resulted in reduction in lightness and yellowness and an
increase in redness in raw and chicken hamburgers without affecting the
acceptability of the products (Ayerdi et al., 2009).
Grape wine has resveratrol, a strong antioxidant and a free-radical scav-
enger. It has superior AOA over quercetin, rutin, and carnosine. Antioxida-
tive effectiveness has been reported as BHA > resveratrol > PG > tripoly-
phosphate > vanillin > phenol > BHT > α-tocopherol (Bekhit et al., 2003).

5.3.1.22 GREEN TEA

Antioxidant properties are attributed to the presence of tea catechins (TC),
epicatechins, epigallocatechin, epigallocatechin gallate, and epicatechin
gallate. These compounds have high affinity for lipid bilayers of muscle
and the radical scavenging activity which prevent lipid oxidation and also
have antibacterial action. TC can also reduce the formation of peroxides
more effectively than α-tocopherol or BHA in canola oil and chicken fat and
fish muscle model system. It has been observed that TC added at a level of
300 mg/kg inhibited the pro-oxidative effect of 1% NaCl and controlled the
lipid oxidation for all the cooked patties during refrigerated storage. It (200
or 400 mg/kg) caused discoloration in cooked patties possibly by binding
with the iron component of myoglobin.