Feasibility of ethanol production from coffee husks

Abstract

The objective of this work was to evaluate the feasibility of ethanol production by fermentation of coffee husks by Saccharomyces cerevisiae. Batch fermentation studies were performed employing whole and ground coffee husks, and aqueous extract from ground coffee husks. It was observed that fermentation yield decreased with an increase in yeast concentration. The best results were obtained for the following conditions: whole coffee husks, 3 g yeast/l substrate, temperature of 30 degrees C. Under these conditions ethanol production was 8.49 +/- 0.29 g/100 g dry basis (13.6 +/- 0.5 g ethanol/l), a satisfactory value in comparison to literature data for other residues such as corn stalks, barley straw and hydrolyzed wheat stillage (5-11 g ethanol/l). Such results indicate that coffee husks present excellent potential for residue-based ethanol production.

Discrimination between roasted coffee, roasted corn and coffee husks by Diffuse Reflectance Infrared Fourier Transform Spectroscopy

“…Although the samples in those studies were not submitted to roasting, the lipids content is not expected to vary during roasting of corn, as it is known to occur with coffee, and the peak assignment to CeH stretching in lipids might still be valid. Furthermore, the reported amounts of lipids (Gouvea, Torres, Franca, Oliveira, & Oliveira, 2009;Moreau, 2002;Oliveira, Franca, Mendonça, & Barros-Junior, 2006) present in coffee husks (1.5e3 g/100 g) are quite low in comparison to coffee beans (12e16 g/100 g) and corn kernels (3e5 g/100 g). Therefore, such bands may be affected by both caffeine and lipids levels in the case of coffee, and are most likely primarily associated to caffeine in the case of coffee husks and only to lipids in the case of roasted corn.…”

Functional properties of coffee and coffee by-products

“…Up to now, most progress has been achieved in their use for industrial purposes other than food industry, such has energy production (Kondamudi, Mohapatra, & Misra, 2008;Saenger, Hartge, Werther, Ogada, & Siagi, 2001), adsorption of compounds (Franca, Oliveira, & Ferreira, 2009;Franca, Oliveira, Nunes, & Alves, 2010;Oliveira, Franca, Alves, & Rocha, 2008; and manufacturing of industrial products, such as particleboards, ethanol, gibberellic acid and α-amylase (Bekalo & Reinhardt, 2010;Gouvea, Torres, Franca, Oliveira, & Oliveira, 2009;Machado, Soccol, de Oliveira, & Pandey, 2002;Murthy, Naidu, & Srinivas, 2009). Commercialized extracts from the coffee fruits, which contain CGA, condensed proanthocyanidins, quinic and ferulic acid, have shown interesting results for facial skin care (Farris, 2007).…”

Vodka production from potato (Solanum tuberosum L.) using threeSaccharomyces cerevisiaeisolates

“…Furthermore, the average viabilities of baker's yeast and CA11 were >80%, while that of CAT1 was ~76%. According to Gouvea et al , the viability of the cells should be in the range of 80–90% at the end of the fermentation process. The numbers obtained during this study were useful in determining the best conditions for the three strains.…”