Page 329 - Natural Antioxidants, Applications in Foods of Animal Origin

308 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir 7.16 mg/g (Sudha et al., 2007). Apple extracts have been shown to have

potent antioxidant activity and anti-proliferative activity against human
cancer cells (Boyer & Liu, 2004; Leontowicz et al., 2002).
Apple pomaces were subjected to evaluation as potential sources of anti-
oxidant phytochemicals on the basis of their total content of phenolics (from
4.22 to 8.67 mg/g), total flavonoids (from 0.45 to 1.19 mg/g) and total flavan-
3-ols (from 2.27 to 9.51 mg/g), and in vitro antiradical activities (Ćetković
et al., 2008). Some individual phenolic compounds including caffeic and
chlorogenic acids (+)-catechin, and (-)-epicatechin, rutin, quercetin glyco-
sides, and phloridzin were identified and quantified by high performance
liquid chromatography (HPLC). The antiradical activity of apple pomaces
was tested by measuring their ability to scavenge DPPH and hydroxyl
radicals. Eleven different cider apple pomaces (six single-cultivar and five
from the cider-making industry) were analyzed for low molecular phenolic
profiles and antioxidant capacity (García et al., 2009). The Folin index ranged
between 2.3 and 15.1 g gallic acid per kg of dry matter. Major phenols were
flavanols, dihydrochalcones (phloridzin and phloretin-20-xyloglucoside),
flavonols, and cinnamic acids (chlorogenic and caffeic acids). The group of
single-cultivar pomaces had higher contents of chlorogenic acid (-)-epicat-
echin, procyanidin B and dihydrochalcones, whereas the industrial samples
2,
presented higher amounts of up to four unknown compounds, with absorption
maxima between 256 and 284nm. The antioxidant capacity of apple pomace,
as determined by the DPPH and ferric reducing antioxidant power (FRAP)
assays, was between 4.4 and 16.0 g ascorbic acid per kg of dry matter.
Methanolic and acetonic extracts of apple pomace were evaluated for
phenolic profiles, antioxidant properties, and antiviral effects against herpes
simplex virus type 1 (HSV-1) and 2 (HSV-2) (Suárez et al., 2010). Acetone
extraction yielded the higher amounts of phenolic compounds. The extrac-
tion method influenced the phenolic composition although antioxidant
activity correlated weakly with phenols concentration. Among the poly-
phenols analyzed, quercetin glycosides were the most important family,
followed by dihydrochalcones. It was observed that apple pomace extracts
were able to inhibit both HSV-1 and HSV-2 replication in Vero cells by more
than 50%, at non-cytotoxic concentrations. Selectivity indexes (SI) ranged
from 9.5 to 12.2.
Apple skin is rich in many health-enhancing phytonutrients including
flavonoids and phenolic acids (Boyer & Liu, 2004). Apple skin has three to
six folds more flavonoids than apple flesh and has unique flavonoids, such as
quercetin glycosides, not found in the flesh (Wolfe et al., 2003; Wolfe & Liu,
2003). Apple fruit skin is rich source of DF and phenolics. The blanched,