Quantitative Sensomics Profiling of Hop-Derived Bitter Compounds Throughout a Full-Scale Beer Manufacturing Process

Abstract

Although the complex taste profile of beer is well accepted to be reflected by the molecular blueprint of its sensometabolites, the knowledge available on the process-induced transformation of hop-derived phytochemicals into key sensometabolites during beer manufacturing is far from comprehensive. The objective of the present investigation was, therefore, to develop and apply a suitable HPLC-MS/MS method for the simultaneous and comprehensive quantitative monitoring of a total of 69 hop-derived sensometabolites in selected intermediary products throughout a full-scale beer manufacturing process. After data normalization, the individual sensometabolites were arranged into different clusters by means of agglomerative hierarchical analysis and visualized using a sensomics heatmap to verify the structure-specific reaction routes proposed for their formation during the beer brewing process.

Hop beta acids: Properties, significance and utilization.

“…Jejich transformační produkty, které se tvoří při chmelovaru, jsou zdrojem typické hořkosti piva, stabilizují pivní pěnu a díky antiseptickým účinkům zvyšují biologickou trvanlivost piva (Haas, 1994;Schmalreck, 1975). Nejdůležitější podíl na celkové hoř-kosti piva patří transformačním produktům chmelových alfa kyselin, které se při chmelovaru izomerují na příslušné cis-a trans-iso-alfa--kyseliny (Jaskula, 2008;Jaskula, 2010;Haseleu, 2010). V důsledku strukturní odlišnosti nemohou beta kyseliny při chmelovaru izomerovat.…”

“…4) v pivu, jako oxidačního produktu huluponů je zanedbatelná (Haseleu et al, 2010). Hulupony jsou přítomny i v čerstvých chmelových výrobcích (lisovaný chmel, pelety) v důsledku oxidace při posklizňovém zpracování chmele a při skladování chmele jejich obsah vzrůstá.…”

“…4), the oxidation product of hulupons, is negligible in beer (Haseleu et al, 2010). Hulupones are present in fresh hop products (pressed hops, hop pellets) as a result of hop oxidation during post-harvest processing of hops.…”

“…Transformation products of hop alpha acids are the main contributors to the overall beer bitterness. In the course of wort boiling, alpha acids are isomerized to cis-and trans-iso-alpha-acids (Jaskula, 2008;Jaskula, 2010;Haseleu, 2010). As a result of structural differences, hop beta acids cannot isomerize.…”

Kinetic Modeling of Hop Acids during Wort Boiling

“…Iso-alpha-acids are isomerized forms of the alpha-acids (humulones) from the hops. The main transformation products account for up to 70% of the amount of alpha-acids initially added during wort boiling [2]. The iso-alpha-acids are mostly responsible for the characteristic, fine bitter taste and the foam properties of beer.…”