Use of Papain Immobilized on Spherosil for Beer Chillproofing

Papain has been immobilized on Spherosil, a porous silica, by two methods: reaction with glutaraldehyde activated amino groups and direct bonding to acetal groups. Both amino and acetal groups were grafted onto the silica via silane coupling. Best results were given by the second method. This derivative was used on a 1‐L packed bed reactor for continuous processing of beer produced by a fermentor using immobilized Saccharomyces uvarum cells. The papain reactor was effective for on‐line beer chillproofing, as measured by the sensibility of the beer to tannin addition.