Page 339 - Natural Antioxidants, Applications in Foods of Animal Origin

318 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir cardiovascular diseases (Cushine & Lamb, 2005; Nijveldt et al., 2001).

Among all the bioactive compounds present in asparagus spears, saponins,
flavonoids, and hydroxycinnamates are the main compounds responsible
for the characteristics cited above. Rutin is the most abundant flavonoid in
asparagus spears, in addition to others that have been recently described
(Fuentes-Alventosa et al., 2007, 2008).
According to Fuentes-Alventosa et al. (2009a) the method by which
asparagus by-products are treated affects the phytochemical composition
and antioxidant activity of the fiber rich powders. They studied factors such
as the treatment intensity, the solvent used, and the drying system. Among
the asparagus phytochemicals, HCA, saponins, flavonoids, sterols, and
fructans were quantified. HCA varied from 2.31 to 4.91 mg/g of fiber, the
content being affected by the drying system and, in some cases, the solvent.
Treatment intensity while isolation was found to affect the saponin content
in fibers. Saponin content ranged from 2.14 to 3.64 mg/g of fiber. Flavonoids
were most affected by processing conditions, being present (0.6–1.8 mg/g
of fiber) only in three of the samples analyzed. Sterols and fructans were
present in minor amounts, 0.63–1.03 mg/g of fiber and 0.2–1.4 mg/g of fiber,
respectively.
Fuentes-Alventosa et al. (2009b) investigated the effect of extraction
method on chemical composition and functional characteristics of high DF
powders obtained from asparagus by-products. The by-products represented
around 50% of the processed vegetable. All the fiber rich powders had
high concentrations of TDF (62–77%). The proportion of insoluble fiber to
soluble fiber decreased with the severity of treatment, in this way increasing
the physiological quality of the fiber. Functional properties, namely water
holding capacity, oil holding capacity, solubility, and glucose dialysis retar-
dation index (GDRI), varied according to the preparation procedure. These
properties make fiber rich powders from asparagus by-products a valuable
source of DF to be included in the formulation of fiber-enriched foods.

8.5.2.3 CARROT PEEL

Carrot (Daucus carota L.) is a good source of natural antioxidants, espe-
cially carotenoids and phenolic compounds (Prakash et al., 2004; Zhang &
Hamauzu, 2004). After processing, carrot residues such as peels, pomace,
are usually discarded or used as animal feed. These by-products contain high
contents of beneficial substances, especially bioactive compounds with anti-
oxidant activities (Zhang & Hamauzu, 2004). The feasibility study of using