Optimising Beer Stabilisation by the Selective Removal of Tannoids and Sensitive Proteins

Abstract

Colloidal stabilisation of all malt and adjunct lager beers through selective removal of haze sensitive glycoproteins using silica gel and tannoid polyphenols using polyvinylpolypyrrolidone (PVPP) or a polyvinylpyrrolidone (PVP)-modified silica gel has been demonstrated during full brewery production. At this scale PVPP and the PVP-modified silica gel exhibited equivalent binding capability for tannoid polyphenols although PVPP removed additional polyphenolic species. Characterisation of proanthocyanidins following treatment at 4°C with PVPP and the PVP-modified silica gel silica co-product confirmed that PVPP removes a wider range of polyphenolics. Both products exhibited poorer polyphenolic binding capability at 4°C as would be expected for a physical adsorption process.

Prediction of Colloidal Stability of Highly Stabilized Beers by a Modified Chapon Tannoid Content Test

“…The tannoid content test correlates with haze-forming polyphenols and colloidal stability better than other tests, e.g., determination of total polyphenols 11 or determination of flavonoids 19 , and provides reliable results in the range between 20-60 mg/L. The disadvantage of the test is that for a tannoid content below 12 mg/L, it gives a zero response, which is a situation typical for beers stabilized by PVPP for colloidal stability of 6 months and more.…”

A comparison of Czech and Chinese varieties of barley with regards to technologically important polyphenolic substances.

“…Spektrum jejich vlastností, týkajících se pivovarské technologie a zejména vlastností hotového produktu, je velice široké. V minulosti se studium polyfenolových sloučenin soustřeďovalo zejména na jejich roli v procesu tvorby polyfenol-bílkovinných komplexů, a tím i na vliv polyfenolů na koloidní stabilitu piva (McMurrough et al, 1996a;McMurrough et al, 1996b;Parker, 2007, Aron a Shellhammer, 2010Rehmanji et al, 2005) a možnosti selektivního odstraňování prekursorů vzniku zákalu (Leiper et al, 2005). Po zavedení moderních stabilizačních postupů, schopných odstranit z piva velkou část polyfenolů, byla tato problematika poměrně dlouhou dobu považována za vyřešenou a pozornost se posunula směrem k antioxidačním vlastnostem polyfenolů (Rice-Evans et al, 1996;Pietta, 2000; Dvořáková et al, 2008a), ať už s ohledem na tvorbu senzoricky nežádoucích produktů, zejména karbonylů (Vandehaegen et al, 2006;Mikyška et al, 2011) The aim of this study was to find differences in the quantity and presence of selected polyphenolic substances in barley grown in the Czech Republic and in the People's Republic of China.…”

“…The range of their properties with regards to beer technology and especially to the quality of the final product is wide. In the past, polyphenols were often studied mainly with regards to their significance in the process of the formation of polyphenols-protein complexes which influence the colloidal stability of beer (McMurrough et al, 1996a;McMurrough et al, 1996b;Parker, 2007;Aron and Shellhammer, 2010;Rehmanji et al, 2005) and to the possible a selective removal of these haze-active precursors from beer (Leiper et al, 2005). This matter was considered as solved with the introduction of modern stabilization methods able to remove a large part of the polyphenols.…”

Effect of ultrafiltration and fining adsorbents on the clarification of green tea

“…So the clarity of tea infusion changes, causing the change of light scattering, and the phenomena is called ''tea cream" (Davies, 1998) or ''chill haze" (Peterson, 2003). The driver in haze formation is the complex formation between monomeric or dimeric polyphenols and proteins, to form a larger colloidal particle (Leiper et al, 2005;Rehmanji et al, 2005;McMurrough and O'Rourke, 1997) during storage, it can be observed with a turbidimeter or visually.…”