Abstract: Monoterpene compounds are important components in hops and beer, responsible for the typical hop aroma attributes in beer. In nature, these compounds exist in both free and glycosidically bound forms. This review focuses on recent progress in understanding the monoterpene biosynthesis pathways, the key enzymes and genes involved in monoterpene synthesis in hops and the important enzymes responsible for the conversion of monoterpene alcohols during beer fermentation. Meanwhile, the change of monoterpenoids in hops and beer and the factors affecting it, as well as the structures and contents of glycoside-bound monoterpenoids and analytical methods for the analysis of these compounds are also reviewed in this paper. Finally, future research directions are discussed.

Key words: hops, beer, aroma compounds, monoterpenes, biosynthesis pathway