제주산 쌀보리 추출물의 항산화 활성 및 성분 분석

Abstract

Barley (Hordeum vulgare L) contains health beneficial phytochemicals such as phenolic acids, flavonoids, lignans, and tocols. This study was conducted to investigate antioxidant activity of hulless, premature, and black Jeju barley that were compared with unpolished and polished milling. In order to identify and quantify antioxidant compounds, total phenolic contents (TPC), total flavonoid contents (TFC), phenolic compounds, and tocols (tocopherols and tocotrienols) were analyzed by high performance liquid chromatography (HPLC). In addition, in vitro antioxidant and whitening activities of Jeju barley were investigated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, 2,2'-azino-bis(3-ehtylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging, superoxide dismutase activity (SOD), hydrogen peroxide scavenging (H2O2), metal chelating effect (Fe2+), reducing power and tyrosinase inhibition. Consequently, total phenolic and flavonoid contents in unpolished barley groups (139.99-149.90 μg GAE/g and 0.89-1.01 μg QE/g), were higher than that in polished barley 89.14-125.45 μg GAE/g, 0.50-0.54 μg QE/g. Gallic acid (1.55-2.98 μg/g) and protocatechuic acid (0.67-2.84 μg/g) were the predominant phenolic compounds in Jeju barley. The total tocols and α-tocotrienol concentration of unpolished barley groups were significantly higher than those of polished barley (p<0.05). Excepting metal chelating effect and reducing power, the in vitro antioxidant activities of unpolished barley group were significantly higher than those of polished barley. Tyrosinase inhibition activity of unpolished and polished were in the range of 82.75-86.48 and 81.26-84.41%, respectively, similar to kojic acid (82.83%), a positive control. The unpolished Jeju barley showed greater antioxidative compounds and activities than polished Jeju barley. These results indicated that Jeju barley, is expected to be used as a natural antioxidant at food and cosmetic industry.