Utilization of coffee by-products obtained from semi-washed process for production of value-added compounds.

Bioresource technology

PubMedID: 24907573

Bonilla-Hermosa VA, Duarte WF, Schwan RF. Utilization of coffee by-products obtained from semi-washed process for production of value-added compounds. Bioresour Technol. 2014;166C142-150.
The semi-dry processing of coffee generates significant amounts of coffee pulp and wastewater. This study evaluated the production of bioethanol and volatile compounds of eight yeast strains cultivated in a mixture of these residues. Hanseniaspora uvarum UFLA CAF76 showed the best fermentation performance; hence it was selected to evaluate different culture medium compositions and inoculum size. The best results were obtained with 12% w/v of coffee pulp, 1g/L of yeast extract and 0.3g/L of inoculum. Using these conditions, fermentation in 1 L of medium was carried out, achieving higher ethanol yield, productivity and efficiency with values of 0.48g/g, 0.55g/L h and 94.11% respectively. Twenty-one volatile compounds corresponding to higher alcohols, acetates, terpenes, aldehydes and volatile acids were identified by GC-FID. Such results indicate that coffee residues show an excellent potential as substrates for production of value-added compounds. H. uvarum demonstrated high fermentative capacity using these residues.