Barley’s nutritional value as a health food is increasing due to its excellent nutritional functionality. In this study, the levels of β-glucan, total polyphenols, and total flavonoids were analyzed in the ethanol extracts of different barley cultivars (Hinchalssal, Heuksoojeongchal, Betaone, Ganghochung, and Saechalssal). Also, the free radical scavenging abilities of 2,2-diphenyl-1-picrylhydrazil (DPPH) and 2,2’-azino-bis-3-ethylbenzo-thiaxoline-6-sulfonic acid (ABTS) were measured to determine their antioxidant activity. The results confirmed that Betaone extract contained highly activefunctional components and exhibitedantioxidant activity. Next, we evaluated the hepatoprotective and inhibitory effects of reactive oxygen species (ROS) generated by barley ethanol extracts after inducing oxidative stress with tert-butyl hydroperoxide (tBHP) in HepG2 cells. Hinchalssal and Saechalssal extracts showed the most significant cytoprotective effect and also reduced ROS production significantly. These results suggest that Hinchalssal, Saechalssal, and Betaone represent potential natural antioxidant and hepatoprotective agents.

Specialty barley extracts were prepared and investigated for its antioxidant activity and biological activity. Hunter L* values of the Iksan 86 extracts had higher than that of the Iksan 87 and Zasoojeongchal extracts. The extraction yields of Iksan 86, Iksan 87, and Zasoojeongchal was 8.08, 6.62, and 7.30%, respectively. The contents of total phenolic compounds of the Iksan 86, Iksan 87, and Zasoojeongchal extracts were 16.24, 15.51, and 13.95 GAE mg/g of sample, respectively. The DPPH radical scavenging activity of Iksan 86, Iksan 87, and Zasoojeongchal extracts were 50.00, 33.27, and 7.56% at a 500 ppm, respectively. The samples showed an inhibition of xanthin oxidase. ACE inhibition effect of specialty barley extracts, Iksan 86, Iksan 87, and Zasoojeongchal, was 39.81, 41.06, and 27.78%, respectively. Tyrosinase inhibition rates (%) of Iksan 86, Iksan 87, and Zasoojeongchal extracts were 26.21, 24.57, and 20.00%, respectively. Results indicated that specialty barley extracts possesses various biological activities including antioxidative capacity, xanthin oxidase inhibition activity, angiotensin converting enzyme inhibition activity, and tyrosinase inhibition activity.

Barley (Hordeum vulgare L.) and barley byproduct, waxy and non waxy genetic type, were prepared and investigated for its biological activity. The total phenolic contents, tyrosinase and xanthin oxidase inhibition activity of the barley extracts were measured and compared with those of a barley byproducts extracts powder. The contents of total phenolic compounds of the barley byproducts, waxy and non waxy type, were 18.60 and 17.92 mg/g of sample, respectively. Inhibition rates (%) of the mushroom tyrosinase of the waxy type barley and barley byproducts extracts powder were 16.30 and 33.60% at 250 ppm, respectively. Tyrosinase inhibition activity of barley byproduct extracts regardless of waxy and non waxy type showed higher than that of arbutin (5%). The samples showed an inhibition effect of xanthin oxidase. At 2,500 ppm of sample concentration, the inhibition effect of xanthine oxidase of waxy type barley (WB), non waxy type barley (NB), waxy type barley byproducts (WBP), and non waxy type barley byproducts (NBP) was 9.92, 16.06, 14.11, and 13.86%, respectively.

A series of methanol extracts from leaf and root parts in spring- and winter-barley plants were assayed to determine their allelopathy and antioxidant activity. The methanol extracts applied on filter paper in a Petri-dish significantly inhibited root growth of Chinese milkvetch (Astragalus sinicus L.) seedlings. Leaf extracts at 25 and 50 g L-1 inhibited root growth of Chinese milkvetch seedlings more than root extracts. No difference in phytotoxic effects of spring- and winter-barley seedlings extracts on root growth of Chinese milkvetch was observed. Methanol extracts dose-dependently increased DPPH free radical scavenging activity in vitro. DPPH free radical scavenging activity was higher in the methanol extracts from winter-barley seedlings than in those from spring-barley seedlings, and from leaf extracts than from root extracts. The antioxidant potential of the individual fraction from the methanol extracts of spring-barley seedlings was in order of n-butanol>ethyl acetate>water>chloroform>n-hexane fraction. By means of HPLC analysis, spring-barley (200.62 mg 100g-1 ) had more amount of total phenol acid than winter-barley (114.08 mg 100g-1 ). Especially, ferulic acid was detected in spring-barley extract (183.46 mg 100g-1 ) as the greatest amount. These results suggest that early seedlings of barley plants had potent allelopathy and antioxidant activity, and their activities were differently exhibited depending on plant parts and growing condition.

Cereal grains are rich in phenolic compounds that give beneficial effect in human health. Although several research works have been reported on the effects of phytochemicals of plant origin, such as fruits, vegetables, few studies have examined the antioxidative effects of whole cereal grains. The objective of this study was to determine total antioxidant capacity of 80% ethanolic extracts of cereal grains by testing the ability of the extracts to inhibit UV -induced lipid peroxidation in vitro using linoleic acid in comparison to well-known antioxidant such as ascorbic acid and tannic acid. The total phenolic content of the cereal grain (80% ethanolic extracts) investigated in this study varied from 2.1 mg/g (wheat cv. Olgeurumil) to 10.4 mg/g (barely cv. Seodunchalbori). Highly positive relationship between total phenol compounds and antioxidant activity was found. When the antioxidant activities of all investigated extracts were measured with application of same quantity of phenol compounds, oat grain extracts showed similar antioxidant activity of barely cultivars. However, barely extract appeared as the most potent antioxidant activity of inhibition of UV -induced lipid peroxidation. This indicated that factors such as phenolic compound composition and their individual antioxidant activity could playa crucial role in the total antioxidant activity of cereal grains.