Phenolic Content and Their Antiradical Activity of The Hops (Humulus lupulus L.) Varieties Cultivated in Turkey

Abstract

The phenolic content and antioxidant capacity of two hops (Humulus lupulus L.) varieties (code E and G) cultivated from Bilecik region in Turkey were investigated. The total phenolic content was determined by using the Folin Ciocalteu assay and expressed as gallic acid (mg GAE/g hop pellets) equivalents. Antioxidant activity of hop pellets were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays and expressed as EC50 (μg/ml), the concentration necessary for 50% reduction of DPPH. The highest total phenolic content for E and G pellets were 112.76 ± 6.02 and 111.05 ± 1.63 mg GAE/g methanol extracts of hop pellets. The EC50 values were in the ranged from 36.4 ± 2.0 to 39.9 ± 0.4 μg/ml. The code G of hop pellets had higher antioxidant activities and the lowest EC50 values. Some chemical properties of hops varieties were assessed. Moisture content, ash value and crude protein (N* 6.25) were ranged from 10.72 ± 0.25 to 11.58 ± 0.02%, 7.49 ± 0.04 to 9.79 ± 0.03%, 15.13 ± 0.15 to 17.06 ± 0.03%, respectively. Carbohydrate and fiber content was estimated by difference of the other components. Oil from hops pellet was extracted using n-hexane for 6 h followed by solvent removal under vacuum at 40 °C. The highest oil content was found 18.70% in Code G hop pellets.