The total contents of phenolic acids measured by high-performance liquid-chromatography were 5-8 mg/litre in beers brewed in Ireland whereas 16-40 mg/litre were present in four other beers. In all beers the predominant phenolic acids were vanillic, p-coumaric and ferulic acids. Free phenolic acids were extracted from Emma barley grains and malt in very small amounts (15-28 mg/kg) but larger quantities (191 mg/kg) were released on mashing the malt. Little change occurred in the contents of phenolic acids on processing a lager wort through to the finished beer. Treatment with excess Polyclar AT removed astringent flavour and phenolic acids from an experimental ale but this flavour loss could not be accounted for by the adsorption of phenolic acids. The flavour threshold for a nine-component phenolic acid mixture in lager was between 50 mg/litre and 100 mg/litre.Key words: adsorbent, astringent taste, beer, highperformance liquid-chromatography. phenolic acids, wort. IntroductionInterest in the phenolic constituents of beers has concen trated closely on those polyphenols implicated in nonbiological haze formation.27 Sporadically, attention has turned to the still uncertain impact on flavour of the numerous simple and complex phenolic compounds present in beer. 71219-20-22'15 In common with most vegetable matter the raw materials of brewing contain a diversity of phenolic compounds, but only small amounts occur therein in a simple free state.29 Usually, phenolic substances are present in living tissues in conjugated forms, of which the most com mon type is the phenolic glycoside. Significantly, in this structural form the toxicity ofdiphenols(e.#. protocatcchuic acid) for living organisms is decreased greatly. Caffeic acid, the most common of the hydroxycinnamic acids, occurs most frequently as a quinic acid ester such as chlorogenic acid.29 Another hydroxycinnamic acid, ferulic acid, is usually bound to cell wall cellulose or associated with protein, and can inhibit germination if free in cereal grains.The quantitative analysis of plant extract for simple phenolic substances has improved greatly in recent years through the application of high-performance liquidchromatography (HPLC). Using this technique substituted hydroxybenzoic and hydroxycinnamic acids from many sources have been separated8-'-13-33-'8''"-49-51-56 but the glycosides and quinic acid esters of phenolics have been less exten sively studied.5-9-'6-30-52-39 Several reports '10-11-21-51'12-43'14 refer to the use of HPLC for measuring the contents of simple phe nolic acids in worts and beers. While there is general agree ment on the qualitative composition of beers the amounts of the different phenolic acids can vary widely. In a compre hensive study53-54 of phenolic acids in German beers the indi vidual acids were found usually at much less than 10 mg/litre and frequently amounted to less than I mg/litre. For some phenolic acids, especially the hydroxybenzoic acid deriva tives, the levels reported by other workers42-43 for some American beers were up...

‘Nacional’ cocoa from Ecuador is a genetic group acknowledged for its ‘Arriba’ floral flavour, which has partly been lost due to the introduction of other more productive varieties. Between 1996 and 2000, 115 Nacional cocoa trees were identified by high yield, resistance to diseases and intense floral flavour, and reproduced by grafting. Some of the progeny are now fruiting and show resistance to Crinipellis perniciosa with an intense floral flavour. Copyright © 2004 Whurr Publishers Ltd