Abstract:

In order to improve the utilization of beer yeast and flavor the beer yeast extract , a method combined the autolysis with the enzyme hydrolysis was employed to produce beer yeast extract , and the Maillard reaction was used to flavor the extract. The results show that the autolysis combined with enzyme hydrolysis is an ideal method to produce beer yeast extract , by which an extraction rate of 68.6% and a protein utilization rate of 87.3% are respectively achieved , and the contents of the total nitrogen and dissociated amino nitrogen reach 10.6% and 4. 3% , respectively. The results also reveal an optimized procedure of Maillard reaction , i. e. , adding 3 % ribose , 2% methionine and 1 % VBl in the solution of 50% beer yeast extract , and adjusting the pH value to 7.5 , then carrying out the reaction at 105℃ for 2 h. The cell wall of the yeast after the enzyme hydrolysis can be used to produce β-glucan with high activity. After the Mai1lard reaction , the flavor of the extract has been greatly improved.

Key words: beer yeast, yeast extract, autolysis-enzyme hydrolysis, β-glucan, Maillard reaction