DPPH, ABTS, AND APX ANTIOXIDANT IN RAW AND COOKED BROWNISH YELLOW AND PURPLE POTATO TUBERS
Man Kyu Huh* and In Sook Kye
This study was to evaluate and compare the antioxidant of extracts from common brownish yellow potato and purple potato cultivars during cooking methods. The colored skin potatoes generally had slightly higher antioxidant activity in raw states than common brownish yellow cultivars. Three antioxidant properties were analyzed using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ascorbate peroxidase (APX) scavenging activity. The DPPH, ABTS, and APX activity of the raw potatoes was high, but not when boiled or baked. DPPH scavenging activity of the raw purple potato was evaluated at 1.0 mg/ml was 53.5%, that of boiled potato was 45.8% at same concentration. Although purple potatoes were slightly higher in DPPH activity than common potatoes, there was no significant difference (p > 0.05). ABTS scavenging activity of raw of common brownish yellow potato was evaluated at 1.0 mg/ml of water extracts was 33.0%, those of boiled and roasted potatoes at same concentration were 8.2% and 11.9%, respectively. APX scavenging activity of raw common potato was evaluated at 1.0 mg/ml was 43.3%, those of boiled and roasted potatoes were 18.1% and 17.4% at same concentration, DPPH, ABTS, and APX scavenging activities were shown a significant difference between raw and cooked (boiled and roasted) potatoes (p < 0.05). Boiling and roasting treatments showed reducing effects on the antioxidant properties of common brownish yellow potato and purple potato cultivars. Namely, antioxidant capacity of potatoes were significantly lost during common cooking practices such as boiling and roasting.
Keywords: ABTS, APX, DPPH, yellow potato and purple potatoes.
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