Hydrolysis of 16.6% (w/v) coffee pulp suspension was first carried out at 121 C for 30 min in presence of 0.18 mol L1 H2SO4.
Afterwards the pH was adjusted manually to 5 by adding 20%
(w/w) NaOH. As a second step the chemically pretreated coffee
pulp was enzymatically hydrolyzed using Accellerase 1500. Per
gram of initially added coffee pulp 0.3 mL of Accellerase 1500
was added and the reaction carried out stirred (150 rpm) at 50 C
for 24 h in a 2 L BIOSTAT bioreactor (Sartorius AG, Germany).