1. Novel Procedure for Lager Beer Clarification and Stabilization Using Sequential Enzymatic, Centrifugal, Regenerable PVPP and Crossflow Microfiltration Processing.
- Author
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Cimini, Alessio, Marconi, Ombretta, Perretti, Giuseppe, and Moresi, Mauro
- Subjects
LAGER beer ,MICROFILTRATION ,BREWING ,ARTIFICIAL membranes ,FLOW velocity ,POLYSACCHARIDES - Abstract
In this work, the crossflow microfiltration (CFMF) performance of different lots of lager beer, produced in a pilot scale at the Italian Brewing Research Centre (CERB, Perugia, Italy), was assessed in a bench-top plant, equipped with a 0.8-μm ceramic tubular membrane module, under constant crossflow velocity of 6 m s, transmembrane pressure difference of 3.74 bar, temperature of ~10 °C, and periodic CO backflushing. By feeding different beer samples (i.e., as such, precentrifuged (C), or pretreated with a commercial enzyme preparation to degrade the original arabinoxylans and β-glucans and then centrifuged (EC) to minimize the fouling contribution of yeast cells, aggregates, and polysaccharides), it was possible to increase the average permeation flux (expressed as mean value ± standard deviation) from 112 ± 13 to 199 ± 17 or 330 ± 22 L m h, respectively. Only when using the EC-pretreated beer specimens, the permeate turbidity at 20 °C approached the limiting one (<0.6 EBC unit) recommended by the European Brewery Convention standards. As expected, the permeate chill haze at 0 °C was generally higher than the above haze target. By submitting EC-pretreated beer seeded with 0.5 g L of regenerable polyvinylpolypyrrolidone (PVPP) to CFMF, it was possible to reduce the initial total polyphenol content by 30 % and permeate chill haze to 0.60 ± 0.01 EBC unit, but the average permeation flux fell to 84 ± 4 L m h. By performing sequentially EC pretreatments, PVPP stabilization, cartridge filtration, and CFMF, it was possible not only to re-enhance the average permeation flux at about 230 L m h near to those achievable with DE filters, but also to obtain a chill haze-free permeate ready for aseptic packaging. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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