Current concepts on polyphenols and beer stability.
The major role of polyphenols in colloidal and flavour stabilities of beer is discussed in light of recent experimental data. The mechanism of haze formation is presented as an interaction between polyphenols and carbohydrates. General chemical composition of hazes is given with particular reference to phenolics. Interdependence of colloidal and flavour stabilities of beer is illustrated through a pivotal role of polyphenols. The existing methods for shelf life prediction are critically reviewed and it is concluded that none is reliable. Various techniques for beer stabilisation are classified into pre brewing, brewing and post brewing measures. The best procedures for stabilising beer are recommended with an emphasis on the use of barley malts with the optimal tanninogen (anthocyanogen and catechin) contents along with proper brewing techniques.
Keywords: beer colloid composition flavour haze polyphenol stability