Laboratory scale fermentation
Fermentations were carried out in triplicate at 52 C and pH 6 with coffee pulp hydrolysate in presence of 10 g L1 yeast extract (Ohly KAT, Deutsche Hefewerke GmbH & Co. OHG, Germany).
For all fermentations a 2 L BIOSTAT bioreactor (Sartorius AG, Germany) containing 1 L of coffee pulp hydrolysate was used. Stirring occurred at 400 rpm using a double Rushton turbine.
Regulation of pH was carried out by adding 20% (w/w) NaOH. A 6% (v/v) inoculum was used in all fermentations. Samples were taken regularly for the analysis of sugar (glucose, xylose, arabinose and sucrose) and lactic acid concentrations.
Samples were inactivated by heating at 95 C for 20 min. After inactivation, samples were stored at
20 C until used in analysis.