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Crossflow-Mikrofiltration mit Keramikmembranen zur Rückgewinnung von Bier von Tankgelägen - Ceramic membrane cross-flow microfiltration for beer recovery from tank bottoms
Bugan, S.G., Dömény, Z., Smogrovicová, D., Svitel, J., Schlosser, S., Stopka, J.
Cross-flow microfiltration with ceramic membranes was applied for beer recovery from tank bottoms. The cross-flow microfiltration was optimised using model yeast suspension and the effects of pore size, flow speed and transmembrane pressure were characterised. Using 200??m pore-size membranes and back-flush in 5?min intervals during filtration of tank bottoms, filtration rate 20?kg/m2 h-1 compared to 3 kg/m2 h-1 without back-flush was achieved. The quality of beer recovered from tank bottoms was extensively evaluated. Increased values of some beer components were found in recovered beer when 200??m membranes were used: bitterness increased from 20 to 36 ?EBC, total nitrogen from 78.4 to 172.1 mg/100 ml, polyphenols from 20.4 to 56.4 mg/l and diacetyl from 0.11 to 0.41 mg/l. Pore-size in range 100-500??m has effect on filtration rate but no influence on beer quality. Some parameters of recovered beer, such as extract, alcohol, pH are not changed. Analyse of 7 fractions collected during beer recovery showed that values are generally increased in last fractions.
Descriptors: Bier, Mikrofiltration, Tankböden
Monatsschrift für Brauwissenschaft 53, Nr. 11/12, 229, 2000