Page 303 - Natural Antioxidants, Applications in Foods of Animal Origin

282 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir extracted using ethanol (80 %), ethyl acetate, and n-hexane and the oxida-

tive stability of ghee during storage under thermal oxidative conditions was
reported. Ethanol extract showed slightly better antioxidant characteristics
compared with ethyl acetate and hexane extracts. It could be due to the
reason that extracts obtained from higher-polarity solvents were more effec-
tive radical scavengers than those obtained using lower-polarity solvents.
Extracts obtained from PS exhibited strong antioxidant capacity in all assays,
followed by PP and OP extracts (El-Shourbagy & El-Zahar, 2014).
In a subsequent study, Asha et al. (2015) evaluated the antioxidant activi-
ties of BHA and orange peel powder extract in ghee stored at different storage
temperatures during the storage period of 21 days. Ghee incorporated with
orange peel extract (OPE) showed stronger activity in quenching DPPH
radicals and least development of peroxide value, free fatty acid content and
TBA than ghee incorporated with BHA and control. The study revealed that
orange peel could be a good natural source of antioxidants which could be
used in fat rich food products like ghee to retard oxidative deterioration.

7.9.3 FERMENTED MILK PRODUCTS

Yogurt is among the most common dairy products consumed around the
world (Saint-Eve et al., 2006). Yoghurt with added antioxidants from natural
sources appears to be a convenient food format to satisfy consumer interest
in terms of beneficial effects of starter cultures, and health benefits of
added antioxidants over original yoghurt nutrients. For this reason, several
attempts to produce yoghurts fortified with natural antioxidant-rich extracts
have been studied, including supplementation with polyphenol-rich wine
extract (Howard et al., 2000), Hibiscus sabdariffa extract (Lwalokun &
Shittu, 2007), pycnogenol from French marine bark extract (Ruggeri et al.,
2008), green bell pepper juice (Halah & Mehanna, 2011), quince scalding
water (Trigueros et al., 2011), apple polyphenols (Sun-Waterhouse et al.,
2012), grape and grape callus extracts (Karaaslan et al., 2011), tea infusions
(Najgebauer-Lejko et al., 2011), grape seed extracts (Chouchouli et al.,
2013), berry polyphenols (Sun-Waterhouse et al., 2013) and pomegranate
peel extracts (PPE) (El-Said et al., 2014).
Chouchouli et al. (2013) evaluated the potential of using grape seed
extracts from two Greek wine grape varieties for the production of anti-
oxidant-rich full-fat and non-fat yoghurts. Fortified yoghurts contained
more polyphenols and exhibited higher antiradical and antioxidant activity
than controls, even after 3–4 weeks of cold storage. The degradation of