Physicochemical, microbiological, and sensory characterization of fermented coffee pulp beverages

Abstract

Coffee pulp is the first by-product generated from coffee processing, a contaminating residue due to its composition and production volume. So, this research presents the use of coffee pulp with honey and sugar cane juice to elaborate alcoholic beverage and infusion. The harvested coffee was washed, pulped; the pulp was distributed in 3 treatments, by duplicates, (T) coffee pulp and water, (M) coffee pulp, water and honey, (G) coffee pulp and sugar cane juice. Then, each treatment was brought to 85 °C for 15 minutes, warmed up and yeast was added to each container. Fermentation was carried out for 14 days at 15 °C. After the liquid was separated from the pulp, the liquid fraction was left to ferment another 14 days, it was clarified with bentonite, it was bottled and for 102 days mature, the degrees of alcohol was measured by simple distillation. The pulp was placed in an oven at 75 °C for 3 days, the chemical composition was analyzed by FTIR, it was packed in hermetic bags, the dry coffee pulp was used to prepare an infusion. For its use, a fermented drink and an infusion were elaborated, evaluating physicochemical, microbiological, and sensorial characteristics through three treatments. The fermented drinks presented values of alcohol degrees 7°- 6°. The treatment with honey obtained a greater acceptance followed by the treatment with sugar cane juice. The infusions were acceptable, differentiated by herbal notes, pleasant aromas, and sweet flavors. In the pulp, the following were characterized by FTIR chemical compounds and wavelengths that show their absorbencies; caffeine with ranges of 2920-2850 and 1620 cm-1, 3280 cm-1 H2O, 1740 cm-1 lipids, 1240 cm-1 chlorogenic acid, and 1015 cm-1 carbohydrates. Finally, the infusions with coffee pulp were accepted by the evaluators, especially those that went through the fermentation process with honey and sugar cane. Keywords: Caffeine; Coffee; Chemical compounds; Fermentation; Sensory analysis.