Biologically active compounds of hop (Humulus lupulus L.) plant and cones

Abstract

Hop (Humulus lupulus L.) is a plant which is probably the best known for being used in the brewery as its cones are responsible for the characteristic bitter taste of beer. Bitter α- and β-acids found in hops cones have antibacterial properties, which in part provides resistance against beer-spoiling microorganisms. Also, other studies show that there are more biologically active compounds (i.e. xanthohumol, 8-prenylnaringenin and others) found in hops that have anti-cancer, radical scavenging, peroxide reducing and antioxidant properties [1-3]. It is very likely that biologically active compounds are accumulated not only in the cones of hops but also in other parts of the plant. There are little data about biologically active compounds in other parts of the hop plant. Identification and optimization of purification processes of biologically active compounds in other parts of the hop plant would probably allow finding more diverse applications of hop harvest. The distribution of biologically active compounds depends on the part of the plant, variety, phase of vegetation and geographical location of the plant. The purpose of this study was to evaluate and compare the phytochemical composition of biologically active compounds in different parts of H. lupulus L. plant growing in Kaunas Botanical Garden of Vytautas Magnus University, Lithuania. To our knowledge, it is the first study about antioxidant activity of different parts of hops collected in Lithuania. The phytochemical composition was analyzed using spectrophotometric methods. The total amount of phenolic compounds, the total content of flavonoids and antiradical activity (using 1,1-diphenyl-2-picrylhydrazyl (DPPH)) were determined [4]. Results were expressed as rutin equivalents mg/g of the plant. The results of the assays will be presented during the conference.