Title: The Effect of Hopping Technology on Lager Beer Flavor and Flavor Stability and the Impact of Polyphenols on Lager Beer Flavor and Physical Stability.

Beer is one of the most extensively consumed beverages world-wide and it is almost always brewed with hops (Humulus lupulus, L.). Hops provide beer with bitterness, aroma, flavor and texture and also enhance specific beer properties such as foam stability, clarity (colloidal stability), color, flavor stability and microbial stability. Hops are a dioecious species, with female plants producing the hop strobilus (cone). The cone is an inflorescence, which is the entire part of the plant that holds the flowers. Hop cones contain lupulin glands (the source of the hop bittering resins), essential oils, and polyphenols (prenylflavonoids). Beer prenylflavonoids such as the flavan-3-ols and their condensed products, the proanthocyanidins, represent a class of readily oxidizable compounds capable of hindering or preventing the oxidation of other molecules present in beer. Flavan-3-ols and proanthocyanidins have recently gained significant consideration as potential beer flavor modifiers and/or stabilizers. However their roles in beer flavor stability have not yet been fully realized. In this study polyphenols were extracted from spent hop (Humulus lupulus L. c