Study on production of yeast extract from beer yeast

The production of the yeast extract made from beer yeast was studied in this paper. After evaluation of single enzyme and enzyme complex interaction of thirteen enzymes belonged to five types, alkaline protease and tryptase were selected as compound enzymes. The optimum conditions were as follows: the ratio of material and water 1:4, the content of compound enzyme 0.4% (account as dry yeast powder, the ration of both enzymes was 2%, respectively), the temperature of enzymatic hydrolysis 45℃, pH 8.5 and the time of enzymatic hydrolysis 18 to 20 h. In these conditions, the yeast extraction of α-amino nitrogen content reached 4587 mg/L. It was proved that application of compound enzyme in production of yeast extract had some advantages, such as high rate of extraction, shorter time of reaction, simple equipment, easy to operate and low-cost.