Page 207 - Natural Antioxidants, Applications in Foods of Animal Origin

186 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir and activate covalently bound phenolic compounds that have antioxi-

dant activities. Therefore, rice hull extract treated by FIR can be a good
candidate to be used in irradiated meat systems as a natural antioxidant.
The antioxidant effect of FIR treated rice hull (Lee et al., 2003) extracts
(FRH) was compared with that of sesamol and rosemary oleoresin in irra-
diated turkey breast meat. FRH significantly decreased TBARS values and
volatile aldehydes (hexanal, pentanal, and propanal) and was effective in
reducing the production of dimethyl disulfide responsible for irradiation
off-odor in irradiated raw and cooked turkey meat during aerobic storage.
The AOA of FRH (0.1%, w/w) was as effective as that of rosemary oleo-
resin (0.1%). However, the addition of FRH increased red and yellow color
intensities and produced an off-odor characteristic to rice hull in raw and
cooked meat, and cannot be used in meat without further refining process
to remove off-color and off-odor compounds to increase its applicability
as an antioxidant.

5.3.1.33 ROSEMARY

The AOA of rosemary (Rosmarinus officinalis L.) extracts has been known
for the last 30 years and is due to presence of phenolic compounds, carnosol,
carnosic acid, rosmanol, isorosmanol, rosmariquinone, rosmaridiphenol,
and rosmary-diphenol. The phenolic substances react with lipid or hydroxyl
radicals and convert them into stable products. Rosemary extracts can also
chelate metal ions, such as Fe , resulting in a reduced rate of formation of
2+
activated oxygen (Formanek et al., 2003). It is four times more effective than
BHA and equal to BHT as antioxidants but less than TBHQ. It also improved
the color stability of cooked turkey rolls. Rosemary extract has also been
used in the combination of various other antioxidants (McBride et al., 2007)
to have synergistic effect. However, some of the compounds in rosemary
(verbenone, borneol, and camphor) can impart an undesirable rosemary odor
to foods, even at low concentrations.
A great deal of research on the antioxidant properties of rosemary extract
in different food systems has been carried out, which clearly demonstrated
the effectiveness of its bioactives compounds with greater acceptability by
the consumers. Moreover, several authors reported that some compounds
such as phenolic di-terpenoids present in rosemary extracts have antibacte-
rial activity (Cuvelier et al., 1994).