Page 328 - Natural Antioxidants, Applications in Foods of Animal Origin

Antioxidant Dietary Fiber: An Approach to Develop Healthy 307
VetBooks.ir of KL (7.9–36.1% DM), neutral sugars (4.9–14.6% DM), and uronic acid

(3.6–8.5% DM) in all five WGP varieties. WWGP was significantly lower
in DF (17.3–28.0% DM) than those of RWGP (51.1–56.3%), but extremely
higher in soluble sugar (55.8–77.5% DM vs 1.3–1.7% DM). Compared with
WWGP, RWGP had higher values in total phenolic content (TPC) (21.4–
26.7 mg GAE/g DM vs 11.6–15.8 mg GAE/g DM) and DPPH radical scav-
enging activity (32.2–40.2 mg AAE/g DM vs 20.5–25.6 mg AAE/g DM).
The total flavanol and proanthocyanidin contents were ranged from 31.0 to
61.2 mg CE/g DM and 8.0 to 24.1 mg/g DM, respectively, for the five WGP
varieties.

8.5.1.2 APPLE BY-PRODUCTS

Apples are well known and widespread fruit of the genus Malus belonging
to the family Rosaceae and play significant part in our diet. They are impor-
tant source of bioavailable polyphenolic compounds such as flavonols,
monomeric and oligomeric flavanols, dihydrochalcones, anthocyanidins,
p-hydroxycinnamic, and p-hydroxybenzoic acids (Escarpa & Gonzalez,
1998). The phenolic contents in apple are variable among different varieties,
and between the peel and the flesh; apple peels contain a higher concentra-
tion of phenolic compounds (Escarpa & Gonzalez, 1998; Vrhovsek et al.,
2004).
Apple pomace is a by-product of the apple juice processing, which is a
rich source of polyphenols, minerals, and DF (Boyer & Liu, 2004; Fernando
et al., 2005; Schieber et al., 2001; Sudha et al., 2007). Disposal of apple
pomace may present an added cost to beverage industry. Fernando et al.
(2005) evaluated some functional properties of apple pomace and reported
that fiber concentrates from apple pomace can be considered as a potential
source for fiber enrichment. According to Lu and Foo (2000), polyphenols
present in apple pomace could be a cheap and readily available source of
dietary antioxidants. The antioxidant capacity of apple pomace is related to
its phenolic profile. Procyanidins have long been recognized as the major
contributors to antioxidant activity of apples (Chinnici et al., 2004; Tsao
et al., 2005) and derivatives (Oszmianski et al., 2008), and the capacity
depends on their polymerization degree and substituents (Lotito et al., 2000).
Additionally, the antioxidant activity of hydroxycinnamic and benzoic acids
and flavonols has been ascertained (Kim et al., 2002; Tsao et al., 2005).
Apple pomace procured from fruit juice industry, contained 10.8% moisture,
0.5% ash, and 51.1% of DF. The total phenol content in apple pomace was