Abstract:

The inhibitory effect of gallic acid on the activities of pancreatic α-amylase and trypsin was studied by varying
enzyme concentration, the sequence of adding substrate, enzyme and gallic acid in reaction systems, reaction time and gallic
acid concentration. Results showed that the maximum inhibition rate (95.52%) of pancreatic α-amylase was achieved by
prewarming the enzyme at a concentration of 0.64 mg/mL in the presence of gallic acid at 37 ℃ for 5 min before addition
of 1 g/100 mL starch and allowing the reaction to proceed for 15 min. Gallic acid exhibited the strongest inhibition on
pancreatic trypsin (by 99.24%) by prewarming their mixture at 40 ℃ for 5 min followed by addition of 1 g/100 mL casein
as the substrate and permitting the reaction to take place for 30 min. The inhibitory effect of gallic acid on both enzyme
activities was positively associated with its concentration.

Key words: gallic acid, pancreatic α-amylase, pancreatic trypsin, inhibitory effect