Page 340 - Natural Antioxidants, Applications in Foods of Animal Origin

Antioxidant Dietary Fiber: An Approach to Develop Healthy 319
VetBooks.ir carrot peels as a starting raw material to produce ADF powder was inves-

tigated (Chantaro et al., 2008). The effects of blanching and hot air drying
(60–80 °C) on the drying kinetics and physicochemical properties of DF
powder were evaluated. The results showed that blanching had a significant
effect on the fiber contents and compositions, water retention and swelling
capacities of the fiber powder. In contrast, drying temperature in the selected
range did not affect the hydration properties. As far as antioxidant activity
is concerned, thermal degradation during both blanching and drying caused
a decrease in the contents of β-carotene and phenolic compounds, hence
leading to the loss of antioxidant activity of the final product.

8.5.3 SEED AND BY-PRODUCTS

8.5.3.1 CEREALS

Cereals and legumes containing wide range of phenolics are good sources of
natural antioxidants (Krings et al., 2000). It has been reported that phenolic
compounds are concentrated in the bran portion of cereal kernels and may
contribute to the total antioxidant activities, suggesting bran a potent source
of antioxidants (Onyeneho & Hettiarachy, 1992). However, it is not clear
at which extent both free and carbohydrate-bound compound are measured
by a given assay (Zhou et al., 2004). Wheat is one of the popular cereal
grains, and its bran represents not only a good source of DFs (Alabaster
et al., 1997), but also of phenolic acids (Baublis et al., 2000). Significant
levels of antioxidant activities have been detected in wheat (Yu et al., 2003;
Zielinski & Kozlowska, 2000), and wheat-based food products (Baublis et
al., 2000), suggesting that wheat may serve as an excellent dietary source of
natural antioxidants for disease prevention and health promotion. Yu et al.
(2002) reported a significant level of TPC, free radical scavenging capac-
ities, chelating activity, and inhibitory effect on lipid peroxidation of the
three-wheat grain extracts with significant differences among the varieties.
Antioxidant activity of wheat bran and flour extracts varies with cultivar and
location (Yu et al., 2002).
Wheat bran, a by-product generated in large amounts during wheat
processing, consists of 36.5–52.4% TDF (Vitaglione et al., 2008), which
makes it a good source of DF. Additionally, wheat and wheat bran has
shown strong antioxidative activities (Li et al., 2005). Several phenolic
acids, including vanillic acid, p-coumaric acid, and, largely, FA have been
found in wheat bran extracts (Kähkönen et al., 1999). These compounds,