Spent brewer's yeast (Saccharomyces cerevisiae) is a rich source of protein, vitamins and widely used as a raw material for production of food supplements. The autolysis and enzymatic treatment of spent brewer's yeast using Pancreatin (2.5%) and Flavourzyme (2.5%) were performed at 45 o C and 50 o C, respectively. The autolysis and hydrolysis processes were evaluated by determining a soluble solids, soluble protein concentration and α-amino nitrogen content in a reaction mixture. The yield of pancreatic digest and α-amino nitrogen content was high in comparison with autolysis and Flavourzyme treatment. The total solids recovery in dry Yeast hydrolysate was about 50%, a protein and α-amino nitrogen content was 55.9 and 4.8%, respectively. These results show the possibility of utilizing the spent brewer's yeast as hydrolysate using hydrolytic enzymes and use it as a food supplement after biological experiments.

Antioxidant activity of pancreatic hydrolysates of casein, spent brewer's yeast, bovine liver and tendon was evaluated in comparison to unhydrolised substrates by ABTS assay. In the result of enzymic treatment ABTS cation radical scavenging activity of spent brewer's yeast, bovine liver and bovine tendon was increased in 4.8, 3.3, and 2.3 times respectively, except casein. The IC 50 values of ABTS cation radical scavenging for casein and it's hydrolysate were similar. The IC 50 values of DPPH radical scavenging activity for pancreatic hydrolysates of casein, spent brewer's yeast, bovine liver and tendon were 1.8±0.1 mg/ml, 1.3±0.1 mg/ml, 1.7±0.1 mg/ml, and 6.2±0.1 mg/ml respectively. Above mentioned hydrolysates of various origin were produced at the same conditions (temperature 50 o C, pH 7.5-8.9, duration 5 hours) using fresh bovine pancreatic tissue as an enzyme source. The extent of hydrolysis expressed as AN/TN (amino nitrogen/ total nitrogen) for hydrolysates had values from 0.36±0.02 to 0.46±0.04.