Page 103 - Natural Antioxidants, Applications in Foods of Animal Origin

82 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir may be useful in such products as their shelf life is expected to be long.

Both synthetic and natural antioxidants or mixtures of both additives are
available for these specialty products. Certain spices, Maillard products
and essential oils could also be tested for this purpose. Sugar-snap cookies
usually stabilized by BHA, are being stabilized with natural antioxidants as
a replacement. Ferulic acid and sodium phytate were found to be suitable as
natural antioxidants (Hix et al., 1997; Pokorný & Trojáková, 2001). Cookies
containing phytate were sensorially fully acceptable. In sugar cookies,
BHT may be replaced by casein, whey proteins, or Maillard reaction prod-
ucts without any loss of storage stability (Ferreira et al., 1996; Pokorný &
Trojáková, 2001). Active natural antioxidants are formed during Maillard
reactions in butter cookies (Bressa et al., 1996; Pokorný & Trojáková, 2001).
Coffee bean components, such as chlorogenic acid, caffeic acid, and roasted
coffee bean powder or extract, have been added to butter cookies to good
effect. The last two natural additives are more active than tocopherol (Ochi
et al., 1994; Pokorný & Trojáková, 2001). Ascorbic and erythorbic acids,
citric acid and its isopropyl ester act as synergists of tocopherols (Ochi et al.,
1993; Pokorný & Trojáková, 2001). The addition of spices, such as extracts
from lemongrass, clove leaves, black pepper leaves, and turmeric increased
the shelf life of cakes and also contributed to their characteristic flavor (Lean
& Mohamed, 1999; Pokorný & Trojáková, 2001). The keeping quality of
crackers and cookies is of great economic importance since these products
are often stored for extended periods before they are consumed (sometimes
after opening the packaging) and they are not protected from oxidation. A
soda cracker biscuit was processed using a fine powder of marjoram, spear-
mint, peppermint, and basil, and their purified diethyl ether extracts as natural
antioxidants. Addition of ether extract from each of the above four plant
materials gave an excellent antioxidative effect compared with the effect of
BHA at concentrations of 0.01, 0.02, and 0.03%. Addition of fine powder
of all plant materials at 0.5% level gave an antioxidant effect compared to
the control sample. Addition of a 1% mixture of equal amounts of the four
plant powders caused a pro-oxidant effect (Bassiouny et al., 1990; Pokorný
& Trojáková, 2001). Carotene in bread and crackers is stabilized against
oxidative bleaching by α-T and ascorbyl palmitate (Ranhotra et al., 1995;
Pokorný & Trojáková, 2001). Large losses of coloration, otherwise observed
during baking, were thus reduced. The shelf life of fruits and vegetables
is limited by factors other than lipid oxidation, for example, antioxidants
are added to fruit and mushrooms to prevent oxidation of polyphenols,
resulting in the enzymic browning (Nisperos-Carriedo et al., 1991; Pokorný
& Trojáková, 2001). The lipid content in fruit and vegetables is about 1%