Abstract The time of the fermentation process of coffee from northern Peru is variable (9 to 48 hours) since coffee farmers do not use standardized processes, causing a variety of coffee qualities. This study aimed to identify volatile compounds in both short (9 hours) and long (32 hours) coffee fermentation processes from coffee farms in northern Peru using Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS) to associate the coffee quality and diversity of volatile compounds. Sensory analyses showed that the short fermentation process (SFP) scored 77.8 ± 0.39 and had chocolate, wood, cardboard, dry, fatty and rough notes, while the long fermentation process (LFP) showed higher punctuations 85.5 ± 3.16 and citrus, fruity, floral, caramel and chocolate sensory attributes. A total of 90 compounds were found in the SFP, whereas 141 compounds were identified in the LFP. Significant differences in the relative abundance of 14 chemical compounds were reported in the SFP and LFP (p < 0.05). From these results, the presence of benzaldehyde, methional, hexanal, 2-heptanone, pentadecane, 1-butanol-3-methyl-acetate, and benzene-acetic acid ethyl ester seems to impact the quality of coffee. The analysis of similarities showed that coffee samples (5 h and 9 h) during the SFP were very variable, whereas coffee samples from LFP showed some tendency to group, which may be related to the difference in altitude and temperature in coffee farms making comparison between them difficult. In addition, this study highlights the complex relationship between coffee fermentation and flavour and the influence of several factors and variables that may affect the composition of flavour and aroma precursors in green coffee beans obtained from wet fermentation.

Resumo O tempo de fermentação do café do norte do Peru é variável (9 a 48 horas), pois os cafeicultores não utilizam processos padronizados, causando uma variação na qualidade dos cafés. O objetivo deste estudo foi identificar compostos voláteis tanto em processos de fermentação de café curtos (9 horas) quanto longos (32 horas) de fazendas de café no norte do Peru, utilizando SPME-GC/MS para associar a qualidade do café à diversidade dos compostos voláteis formados. As análises sensoriais mostraram que o processo de fermentação curto (SFP) resultou em pontuação 77,8 ± 0,39 com notas de chocolate, madeira, papelão, secas, gordurosas e ásperas, enquanto a fermentação longa (LFP) mostrou pontuações de 85,5 ± 3,16 e atributos cítricos, frutados, florais, caramelo e chocolate. Um total de 90 compostos foram encontrados no SFP, enquanto 141 compostos foram identificados no LFP. Diferenças significativas na abundância relativa de 14 compostos químicos foram verificadas entre os processos SFP e LFP (p < 0,05). A partir destes resultados, a presença de benzaldeído, metional, hexanal, 2-heptanona, pentadecano, 1-butanol-3-metil-acetato e éster etílico do ácido benzenoacético parece ter impacto na qualidade do café. A análise das semelhanças mostrou que as amostras de café após 5 h e 9 h de fermentação no SFP foram muito variáveis, enquanto as amostras de café do LFP mostraram alguma tendência ao agrupamento, o que pode estar relacionado com as diferenças de altitude e temperatura nas fazendas de café, tornando difícil a comparação entre elas. Além disso, este estudo destaca a complexa relação entre a fermentação e o sabor do café, e a influência de vários fatores e variáveis que podem afetar a composição de precursores de sabor e aroma em grãos de café verde, obtidos a partir da fermentação úmida.

Abstract Peru is one of the main cocoa exporters worldwide, being the Amazonas region home of the native fine aroma cocoa (CNFA). The objective of this work was to evaluate the physicochemical and organoleptic properties of the CNFA grown in Utcubamba province, Amazonas. The cocoa samples were collected in four areas (Cajaruro, Naranjos Alto, Llunchicate, and La Palma) in which farmers carry out the same postharvest handling practices. Samples underwent a six-day fermentation process and dried in full sun. The physical and chemical parameters of dried beans were evaluated. Then, chocolate pastes were evaluated through a sensory test. We found that the CNFA beans presented optimal physical characteristics to be used at an industrial level. In terms of chemical parameters there was no difference between the percentage of fat. The Cajaruro and Llunchicate samples had lower acidity values and adequate pH, which reflected on their greater acceptance in the sensory test. Therefore, CNFA beans from the Amazonas region, Peru, can be used as raw material to produce gourmet chocolates.

Abstract The objective of the research was to evaluate the antioxidant activity, phenols and volatile compounds of different types coffee infusions. We worked with the Catimor coffee variety and used five methods to obtain the infusion (espresso, V60, siphon, French press and a traditional local method). For each infusion, the antioxidant capacity was determined with the 2,2-Diphenyl-1-Picrylhydrazyl and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid techniques, the phenolic content was determined with the Folin-Ciocalteu technique, and aromatic volatile compounds were determined with gas chromatography coupled with mass spectrometry. The extraction method that yielded the coffee infusions with the most antioxidant activity, phenolic compounds and caffeine content was espresso; however, this coffee had the fewest aromatic volatile compounds. Although they had lower antioxidant activity, the infusions obtained with the French press had the highest content of volatile aromatic compounds and produced a cup that was free of pyridine, an undesirable compound in coffee due to its rotten smell.