THE ROLE OF ACTIVE AND INACTIVATED PAPAIN IN BEER CHILLPROOFING

The mechanism of chillproofing of beer by papain has been studied in a series of three experiments. Changes in the molecular size of proteins and polypeptides have been monitored by chromatographic profiles on Sephadex G-25 columns. Simultaneously the production of free amino acids and changes in the colloidal stability of the beer were determined. The addition of active papain to beer affected all three parameters. By contrast when inactivated papain was added to beer neither the chromatographic profile nor the concentration of free amino acids were altered but an increase in colloidal stability occurred. The removal of active papain from beer did not affect its colloidal stability but the removal of inactivated papain from beer stabilised with this agent eliminated the chillproofing effect.