Urea Removal from Wine by an Acid Urease

Abstract

Urea, the main precursor for ethyl carbamate formation, is present naturally in certain wines. Treatment of these wines with a preparation of killed cells containing an acid urease will remove the major potential source of ethyl carbamate. The action of the enzyme is fairly rapid. The cells can be reused a number of times with little loss in activity. A number of different wines were tested. Variability of the response to the enzyme action was due to pH. In the range of wine pHs, it is most effective at higher pHs. In certain wines some inhibition was noted beyond the pH effect. Methods of use are suggested.