Evaluation of volatile compounds in coffee (Coffea arabica L.) beans in response to biochar applications using an electronic nose

Alefsi David Sánchez-Reinoso1, Carlos Mario Zuluaga-Domínguez1, Leonardo Lombardini2, and Hermann Restrepo-Díaz1*
The use of biochar (BC) seems to be a promising alternative for efficient and environmentally friendly waste management that could help to promote cleaner agricultural production. The objective of this research was to evaluate the aromatic profile of coffee (Coffea arabica L.) beans and cup quality parameters in response to the application of four different doses of biochar (0, 4, 8, and 16 t ha-1) obtained from coffee pulp, and four levels of chemical fertilization (CF) (0%, 33%, 66% and 100% of nutritional requirements). An electronic nose was used to analyze volatile compounds and their relationship with coffee quality parameters: Soluble solids (TSS), pH, titratable acidity. Applications of 8 and 16 t ha-1 BC and 66% and 100% CF registered greater sensitivity to the aromatic compounds of roasted coffee beans in sensors W1C, W3C, and W5C. The BC amendments between 8 and 16 t ha-1 and CF 66% and 100% increased the TSS content (CF 66%: 1.32 °Brix and CF 100%: 1.38 °Brix), reduced the pH (CF 66%: 4.95 and CF 100%: 4.88) and increased titratable acidity (CF 66%: 697.88 mg CaCO3 L-1 and CF 100%: 662.56 mg CaCO3 L-1) in beverages of ‘Castillo El Tambo’ coffee bean in the year 2020. Finally, the co-application of BC as a complement to CF showed a positive effect on the aromatic profile. This methodology could be an original approach to characterize beans according to the coffee crop’s nutritional status, helping in factors focused on quality and traceability.
Keywords: Aromatic profile, cup quality, mineral nutrition, soluble solids.
1Universidad Nacional de Colombia, Facultad de Ciencias Agrarias, Departamento de Agronomía, Carrera 30 No. 5-03, Bogotá, 111321, Colombia.
2University of Georgia, Department of Horticulture, Athens, Georgia, USA.
*Corresponding author (hrestrepod@unal.edu.co).