Abstract:

Antioxidant peptides were prepared by enzymatic hydrolysis of Jerusalem artichoke tuber residue protein with an
acid protease. Substrate concentration, hydrolysis time and pH were identified by the combined use of single factor method
and Plackett-Burman design as the factors with the most significant influence on 1,1-diphenyl-2-picrylhydrazyl (DPPH)
radical scavenging activity of protein hydrolysate. The optimal hydrolysis conditions for enzyme dosage, temperature, pH,
time and substrate concentration were determined by response surface methodology to be 8 000 U/g, 50 ℃, pH 5.0, 3.5 h
and 0.16 g/mL, respectively. Under these conditions, the predicted DPPH radical-scavenging rate was 88.08%, agreeing with
the average experimental value (88.10%).

Key words: response surface methodology, Jerusalem artichoke residue protein, enzymatic hydrolysis, antioxidant peptides