Page 179 - Natural Antioxidants, Applications in Foods of Animal Origin

158 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir cancer and heart diseases by decreasing the amount of plaque buildup in the

blood vessels (McClain & Bausch, 2003). Additionally, they are reported to

increase the amount of high density lipoproteins (HDL), commonly known
as “good cholesterol” in the blood, thus as preventing heart disease (Yao

et al., 2004). These beneficial properties have put natural antioxidant on
the forefront of recent advertising and public awareness concerning natural
antioxidants and their positive effect has increased greatly. Asahara (1987)

studied the antioxidant effect of natural tocopherol mixture on marinated
sardine during cold storage which was compared with the effect of BHA.
Thiobarbituric acid (TBA) value was determined on lipids of samples during
storage time (200 days). Sensory evaluation revealed no negative effect on
the organoleptic properties on the samples. Lemon balm and oregano have
been reported to have a safe history of use as herbal food ingredients, and
their natural extractives are listed as generally recognized as safe (GRAS) in
the United States. Furthermore, herbs and flower tips of Origanum vulgare
and Melissa officinalis have been allocated the status N2 by the Council
of Europe; N2 comprises admissible natural sources of flavorings (Boskou,

2006).

4.7 CONCLUSION

Antioxidants are compounds that are present either naturally or added to food
items to prevent oxidation which always leads to rancidity, browning, and
general lack of freshness. Fish and fish products contain unsaturated fatty
acids which are especially susceptible to oxidation because of their electron
deficient double bonds. The breakdown products of oxidation can produce
off-odors, loss of nutrient content, new flavors, and color deterioration. To
manufacture high-quality, stable fish products, the most effective solution
is the addition of antioxidants, especially natural, which can serve as “chain
breakers,” by intercepting generation of free radicals during various stages
of oxidation or to chelate metals. A common feature of these compounds is
that they have one or more aromatic rings (often phenolic) with one or more
–OH groups capable of donating H to the oxidizing lipid. The facts that
·
they are natural, and have antioxidative activity that is as good as or even
better than the synthetic antioxidants, make them particularly attractive for
commercial food processors. It is clear that consumers are becoming increas-
ingly aware of and selective against foods that are perceived by them to be
unnatural and containing additives. This means that controlling oxidation