Ethanol prodution from mucilage and pulp of processed coffee

Abstract

The present investigation is to evaluate ethanol production from coffee pulp and mucilage as coffee by-products, which was used as substrate. Material and methods: Wort extracted from pulp and mucilage was fermented; molasses sugar was used to optimize in terms of concentration and increase reducing sugars for fermentation process; acid hydrolysis was performed to breakdown complex polysaccharides from pulp and mucilage into simple monomers. Dry yeasts used as Saccharomyces cerevisiae were rehydrated and supplemented by nutrients rich in nitrogen, magnesium and carbon before being pitching in the wort; appropriate materials for hermetic process of fermentation were used and regular controlled. Results and discussion: The variation of reducing sugars in a substance shows the evolution of fermentation process. During this fermentation process, it has been realized that the sugar content has decreased, by comparing with the initial level and final, before and after fermentation, is directly related to the fermentation efficiency. The end of process was realised when the density has decreased below 6%. The obtain results after fermentation, was also continued by conducting distillation; the 6.5l as amount of wort produced 2.3l of ethanol with 45% absolutely volume, equivalent to 35.5% of wort volume. Since pH of wort was optimised to 4-5 for fermentation, the results show that ethanol production can be produced and viable using coffee pulp and mucilage as by-products and reduce the contamination of them to the environment. For this case study, by optimizing alcohol concentration, the pH, and temperature have been kept constant for all samples. Conclusion: Processing of the coffee mucilage and pulp as by-products to ethanol can increase raw material resources suitable for ethanol production for various purposes in Rwanda and this confirm that ethanol production from mucilage and pulp of coffee is possible as results show the potential to use them instead of considering them as waste.

Biorefinery and Stepwise Strategies for Valorizing Coffee By-Products as Bioactive Food Ingredients and Nutraceuticals

“…Additionally, the extraction of simple sugars from the coffee mucilage can serve as a substrate for anaerobic digestion, enabling the production of methane and bioethanol [122,123]. Fermentation of coffee mucilage can also yield ethanol, which finds application as a biofuel or in beverage production [123,124]. The microbial community involved in coffee mucilage fermentation significantly influences the process and impacts the final product quality [125].…”