Sborník 2009 - Vysoká škola chemicko-technologická v Praze

6. seminář – Pivovarství a kvasné technologie 2009, 2.-3.4.2009, ÚKCHB, VŠCHT Praha___________________________________________________________________________Application of polyamide sorbents for improvement of beer colloidalstabilityKhac Tran Diep, Siříšťová Lucie, Dostálek PavelÚstav kvasné chemie a bioinženýrství, VŠCHT PrahaInsoluble polyamides were first used by Harriss and Ricketts in the late 1950sfor beer stabilisation. These investigators showed that Nylon 66 effectivelyremoves anthocyanidins from beer. However, practical use of nylons as acolloidal stability treatment agent has essentially been eliminated, because theycost too much. Therefore in 1960s nylon was replaced by cheaper PVPP. PVPP,which is an insoluble crosslinked form of PVP, represents the most frequentlyused stabiliser for removal of polyphenols nowadays. In 1980s the research ofpolyamides for brewing application was done at the Institute of ChemicalTechnology Prague, where several polyamide sorbents with excellent sorptionactivity were developed. Nowadays a new polyamide (PA) sorbent wasdeveloped. This sorbent is kieselguhr covered by a thin layer of poly-6-caprolactame. The sorbent is prepared by in solution polymerisation in thepresence of kieselguhr. PVPP and PA were compared due to their sorptioncapacity for polyphenols in beer. Sorption capacity was also measured in modelsolutions (catechin in acetate buffer) and industrial scale. There was no principaldifference in sorption capacity between PVPP and PA. However combinationeffect of PA and silicagel gave better colloidal stability than combination effectof PVPP and silicagel. Stabilized beers had longer real shelf-life whileantioxidant power was preserved.