Page 139 - Natural Antioxidants, Applications in Foods of Animal Origin

118 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir antioxidants obtained in vegetables play the major role in maintenance of

health and prevention of diseases (Paganga et al., 1999). It has been esti-
mated that every serving increase in vegetable consumption reduces the risk
of cancer by 15%, cardiovascular disease by 30%, and mortality by 20%
(Steimez & Potter, 1996; Rimm et al., 1996), attributable to antioxidants
such as ascorbic acid, vitamin E, carotenoids, lycopenes, polyphenols, and
other phytochemicals. These antioxidants scavenge radicals and inhibit the
chain initiation or break the chain propagation (the second defense line).
Vitamin E and carotenoids also contribute to the first defense line against
oxidative stress, because they quench singlet oxygen (Krinsky, 2001; Shi et
al., 2001).

3.5.4.1 LEAFY GREEN VEGETABLES

Fresh leafy green vegetables contain important functional food components,
such as β-carotene, ascorbic acid, riboflavin, folic acid, minerals (Grusak
& DellaPenna, 1999), and a large amount of polyphenols (e.g., phenolic
acids, flavonoids, and aromatic compounds). They are also known for their
characteristic color, flavor, and therapeutic value (Gupta et al., 2005; Faller
& Fialho, 2009). Ten common vegetables were screened for their antioxi-
dant and anti-proliferative activities by Chu et al. (2002). Broccoli and
spinach had the highest amount of free phenolics, followed by yellow onion,
red sweet pepper, cabbage, carrot, potato, and lettuce. Cucumber had the
lowest free phenolics of the 10 vegetables. The total antioxidant activity
was determined by total oxyradical scavenging activity (TOSC) assay. Red
pepper, broccoli, carrot, and spinach were in the group with higher anti-
oxidant activities. The medium group comprised cabbage and yellow onion.
The remaining four vegetables in the group with lower antioxidant activities
included celery, potato, lettuce, and cucumber.
Antioxidant activities of 70% ethanolic extracts of 10 leafy green vegeta-
bles were determined and applied in raw beef patties (Kim et al., 2013a). The
extracts and BHT were separately added to patties at 0.1 and 0.5% (w/w)
concentrations and the patties were stored at 4 °C for 12 days. The addi-
tion of extracts and BHT resulted in concentration dependent decreases in
TBARS values in the beef patties and also improved meat color stability. The
fatsia (Aralia elata) extract had more effective antioxidant than the cham-
namul (Pimpinella brachycarpa). In another study, the antioxidant efficacy
of 70% ethanol and water extract of 10 leafy edible plants was evaluated