Journal article
A study on chemical constituents and sugars extraction from spent coffee grounds
IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal1
Department of Biotechnology, Engineering College of Lorena, University of São Paulo, Estrada Municipal do Campinho s/n, 12602-810 Lorena/SP, Brazil2
Spent coffee grounds (SCG), the residual materials obtained during the processing of raw coffee powder to prepare instant coffee, are the main coffee industry residues. In the present work, this material was chemically characterized and subsequently submitted to a dilute acid hydrolysis aiming to recover the hemicellulose sugars.
Reactions were performed according to experimental designs to verify the effects of the variables H2SO4 concentration, liquid-to-solid ratio, temperature, and reaction time, on the efficiency of hydrolysis. SCG was found to be rich in sugars (45.3%, w/w), among of which hemicellulose (constituted by mannose, galactose, and arabinose) and cellulose (glucose homopolymer) correspond to 36.7% (w/w) and 8.6% (w/w), respectively.
Optimal conditions for hemicellulose sugars extraction consisted in using 100mg acid/g dry matter, 10g liquid/g solid, at 163°C for 45min. Under these conditions, hydrolysis efficiencies of 100%, 77.4%, and 89.5% may be achieved for galactan, mannan, and arabinan, respectively, corresponding to a hemicellulose hydrolysis efficiency of 87.4%.
| Language: | English |
|---|---|
| Year: | 2011 |
| Pages: | 368-374 |
| ISSN: | 18791344 and 01448617 |
| Types: | Journal article |
| DOI: | 10.1016/j.carbpol.2010.07.063 |
