Page 164 - Natural Antioxidants, Applications in Foods of Animal Origin

Natural Antioxidants: Control of Oxidation in Fish and Fish Products 143
VetBooks.ir that determine food quality loss and shelf-life reduction. Hence, delaying

oxidation is highly relevant to food processors. Oxidative processes in
fish products can lead to the degradation of lipids and proteins which, in
turn, contribute to the deterioration in texture and color (Decker et al.,
1995).
To combat oxidation in food and physiological context, compounds
known as antioxidants are utilized. Antioxidants are generally defined as
compounds that prevent oxidation. They vary greatly in size, molecular
weight, and composition. While some are small in size others are enor-
mous and can even be macromolecules such as proteins. They provide elec-
tron density to compounds likely to undergo oxidation, hence preventing
them from losing electrons. Since there are different types and sources
of antioxidants, they can be grouped into two major categories: natural
and synthetic. Natural antioxidants are harvested directly from organic
sources or compounds found in foods consumed without much processing
whereas synthetic antioxidants are artificial compounds created in labo-
ratories and generally added to processed or pre-packaged foods acting
as preservatives. Although, synthetic antioxidants have been widely used
to inhibit lipid oxidation, the trend is to decrease their use because of the
growing concern among consumers about such synthetic materials (Chas-

tain et al., 1982). Therefore, the search for natural additives, especially
of plant origin, has increased in recent years. Compounds obtained from
natural sources such as grains, fruit, oilseeds, spices, and vegetables have
been investigated(Chen & Ho, 1997). The development and application of

natural products with antioxidant activities in fish products may be neces-
sary and useful to prolong their shelf life and potential for preventing fish
spoilage.
Natural antioxidants have shown to have significant health benefits espe-
cially in prevention of cancer and heart diseases. Due to this, many food
manufacturers have begun publicizing this fact and have achieved promi-
nence on many food labels on various food products. Although natural anti-
oxidants are known as key supplements by vitamin and health food manu-
facturers, consumers must remain aware of the sources from which these
compounds are procured as well as their concentrations. Therefore, the aim
of this chapter is to elucidate the natural antioxidants commonly applied
to fish, their mode of chemical reaction, and consumer awareness of these
compounds.