Page 300 - Natural Antioxidants, Applications in Foods of Animal Origin

Application of Natural Antioxidants in Dairy Foods 279
VetBooks.ir caused by lipid oxidation include not only loss of flavor or development of

off-flavors, but also loss of color, nutrient value, and the accumulation of
compounds, which may be detrimental to the health of consumers. One of the
most effective ways of retarding lipid oxidation in dairy products is to incor-
porate antioxidants (Gad & Sayd, 2015). The growing interest in the study
of natural antioxidant compounds has been accompanied by an increase in
the market presence of functional foods or nutraceuticals or health foods.
Fortification of dairy products with bioactive components (natural antioxi-
dants compounds) enhances their antioxidant activity and anti-inflammatory
properties, which prevent the damaging effects of free radicals (Berardini et
al., 2005) and provide various health benefits.
Herbs, fruits, vegetables, spices, and other plant materials rich in phenolic
compounds are of growing interest in the food industry because they retard
oxidative degradation of lipids and thereby improve the quality and nutri-
tional value of food (Wojdyło et al., 2007). Numerous herbs have the poten-
tial to retard lipid oxidation during storage of foods which is usually medi-
ated through their intrinsic antioxidant activity. The reports on the addition
of herb and spice extracts in milk and milk products is evolving rapidly
(Pokorny & Korczak, 2001; Pawar et al., 2012) and the same is discussed as
in the next section.

7.9.1 MILK AND MILK BASED BEVERAGES

Several approaches for antioxidant incorporation in milk have been used in
an attempt to reduce lipid oxidation. Jung et al. (1998) added ascorbic acid
(from 200 to 1000 mg/kg) directly to milk and, by using dynamic headspace
analyses and gas chromatography, concluded that formation of dimethyl
disulfide decreased. The result of sensory evaluation revealed that milk
containing ascorbic acid (and therefore less dimethyl disulfide) improved in
flavor in the presence of ascorbic acid.
In a subsequent study, the effect of antioxidants, added in a single initial
dose or in weekly additions to extend shelf life of milk, was evaluated for
over six weeks of lighted storage at 4 °C (van Aardt et al., 2005). Light
induced oxidation was measured by determining pentanal, hexanal, heptanal,
and 1-octen-3-ol contents. Weekly addition of a combination of BHA and
BHT (100 mg/kg of milk fat, each) maintained heptanal content of milk at
levels comparable to light-protected milk, whereas an initial single addition
of α-tocopherol significantly decreased hexanal content over the first four
weeks of storage. Odor-active compounds associated with light-induced