AN-PEP concentration (mg/mL) Enzyme activity (U • 10-1) Incubation time (h) Gluten content (mg/kg)a Bran 1 Bran 2 Bran 3 100 1.2 24 579 ± 42A 22 ± 2A 904 ± 144A 400 4.6 24 127±3B 16 ± 9A 411±28B 100 1.2 48 15±3C <LOQb 215±64C 400 4.6 48 5±0D <LOQb 142±3D 500 5.8 72 n.d.c n.d.c 152±29CD 750 8.7 72 n.d.c n.d.c 170±9C aMean value of duplicate determinations ± standard deviation. Values associated with different capital letters within the same sample denote significant differences (two-sided t-test, p<0.05) bLimit of quantitation (10 mg gluten/kg) cNot determined

Table 1: Gluten content of bran samples as affected by AN-PEP concentration and incubation time. 5 g bran was incubated with 50 μL AN-PEP solution and incubated at 50 °C and pH 4.0. Initial gluten contents of bran 1, 2, and 3 were 107,285 mg/kg, 5,335 mg/kg, and 53,333 mg/kg.