Abstract:
Dietary antioxidants present in fruits and vegetables contribute to the defense
mechanisms against oxidative stress. Brassica spp. are among the vegetables that are rich
in natural antioxidative compounds. To encourage the Brassica spp. consumption through
nutritional counseling among the public, it is important to determine which species have
the highest antioxidant compounds and introduce them regularly into the diet. Thus, this
study was conducted to determine the concentration of ascorbic acid, a-tocopherol and
carotenoid, as well as ascorbate peroxidase (APX), guaiacol peroxidase (gPOD) and
catalase (CAT) specific activities in three different Brassica spp. namely Brassica
oleracea var. capitata f. rubra (red cabbage), Brassica oleracea var. capitata f. alba
(white cabbage) and Brassica rapa var. pekinensis (Chinese cabbage). The carotenoid
concentration varied from 1.054±0.093 to 3.733±0.284 mg/g fwt. Among three Brassica
spp., the maximum carotenoid concentration was detected in red cabbage. Red cabbage
also contained almost 10-fold and 3-fold higher concentration of ascorbic acid
(111.717±11.715 µgig fwt) and a-tocopherol (8.201±0.206 µg/g fwt), respectively
compared to Chinese and white cabbage. Interestingly, red cabbage also showed higher
specific activity of gPOD (504.165±77.388 units/mg protein), which was comparable to
those of white cabbage and 9.5-times higher than Chinese cabbage. Similarly, APX
(120.691±13.164 units/mg protein) and CAT (0.906±0.128 units/mg protein) specific
activities were also observed higher in red cabbage. The results indicated that red cabbage
contained high natural anti oxidative compounds and may provide good sources of dietary
natural antioxidants compared to the Chinese and white cabbage.
