Hybrid carrageenans as beer wort fining agents

Abstract

Pure Na+ forms of furcellaran (β/κ-hybrid carrageenan), κ-carrageenan, κ/ι-hybrid carrageenan, ι-carrageenan and a hybrid carrageenan mix (made up of κ-, ι-, λ- and ν-carrageenans) were tested as beer wort fining agents. To find out which of the used carrageenans are the best beer wort clarifiers and whether they are prone to overdosage, polysaccharides with varying concentrations and molecular weights were tested. The polysaccharides were characterized by 1H NMR spectroscopy and size-exclusion chromatography. The fining efficiency of the tested polysaccharides was measured nephelometrically. Ultrasonicated and alkali treated carrageenan preparations were tested as beer wort fining agents and compared to the native samples. Undegraded furcellaran, κ-carrageenan and κ/ι-hybrids were efficient in lowering the turbidity of various beer worts, but the addition of ι-carrageenan and the carrageenan mix caused the turbidity to rise above the unfined sample value. Compared to the degraded samples, native galactans were more effective in lowering the beer wort turbidity. Higher concentrations of ultrasonicated carrageenans are needed to clarify the beer wort to similar turbidity values. Alkali treated carrageenans were more efficient beer wort fining agents compared to the native samples.