Preparation and antioxidant activity of peptides from brewery waste yeast

The brewery waste yeast contains 50% proteins and has high values of application. The optimal conditions of autolysis were explored by the single-factor tests, and its efficiency was compared with the microwave-assisted hydrolysis and exogenous enzyme hydrolysis. The results showed that the optimal autolysis conditions of the yeast were with a solid-liquid ratio of 1: 20, at pH 6.0 and 45.0℃ for 48h. Under these conditions, yeast protein was hydrolyzed and extracted, the degree of hydrolysis was 41.5%, and protein yield was 42%. The autolysis method showed the same efficiency as the exogenous enzyme hydrolysis, but higher than that of the microwave-assisted hydrolysis. The prepared peptides from yeast by autolysis showed high antioxidant activity.