Effects of production factors and egg-bearing period on the antioxidant activity of enzymatic hydrolysates from shrimp (Pandalopsis dispar) processing byproducts.

The effects of production factors (protease used, percent enzyme, hydrolysis time, and water-to-substrate ratio) on the antioxidant activity of hydrolysates produced from shrimp processing byproducts (SPB) were assessed using Taguchi's L16 (4(5)) fractional factorial design. SPB hydrolysates showed excellent ABTS radical scavenging activity, metal ion chelating capacity, and inhibition of lipid peroxidation, but weak DPPH radical scavenging activity and ferric ion reducing antioxidant power. The protease used significantly influenced antioxidant activities while hydrolysis time and percent enzyme affected radical scavenging activities and inhibition of lipid peroxidation, respectively. Differences in the lipid and amino acid contents observed between SPB collected early and late in the egg-bearing period may have contributed to the slight variance in antioxidant activities displayed by their hydrolysates. Nevertheless, SPB hydrolysates produced using Alcalase or Protamex had high antioxidant activity regardless of production factors and egg-bearing period.