The aim of a recent study, carried out by a group of Chinese researchers (Wang et al., 2024), was to improve commercial Arabica coffee quality combining flavour precursors with an anaerobic germination process. In particular, tests were carried conducted using green coffee beans prepared by incorporating 5 g/100 g of these precursors (sucrose, glucose or fructose).
After roasting, the chemical composition and sensory quality of roasted coffee beans were analysed. The results show that adding flavour precursors facilitates the harmonization of water-soluble chemical components and altered aroma characteristics. Specifically, this inclusion significantly increased the levels of 5-hydroxymethylfurfural and volatile aldehydes.
In addition, the sensory analysis shows that anaerobic germination transformed the aromatic profile of coffee, significantly increasing the product acceptability by the tasters. Sucrose addition produced the highest sensory score and intensified the fruity flavour. In conclusion, the sector’s industry can benefit of the proposed method to improve the quality of Arabica coffee. However, further research is required to explore the mechanisms behind this process, to obtain aroma profiles meeting specific market needs.
The impact of different fermentation techniques on the enhancement the sensory quality of coffee.
Fermentation, a critical post-harvest process, can be strategically manipulated to enhance coffee quality. This improvement is achieved through the activity of microorganisms, which generate fundamental metabolites in the formation of distinct sensory profiles. Therefore, the aim of a recent study, carried out by a team of Brazilian researchers (Silva et al., 2024), was to investigate the impact of different fermentation methods on the quality of coffee beverages, using samples of the Catigua MG2 variety.
In particular, the tests were carried out in 200 L bioreactors, using both natural and pulped coffee beans. The fermentation process used was self-induced anaerobic fermentation (SIAF), conducted in either solid-state or submerged medium over a 96-hour period. Analytical sampling was performed at 24-hour intervals to quantify the concentration of sugars, alcohols and organic acids, while the sensory evaluation was conducted using a panel of 5 people.
The outcomes reveal that each of the fermentation processes tested can significantly enhance the quality of coffee, yielding products with different acid and alcohol profiles, and, consequently, with different sensory characteristics. According to the authors, superior quality beverages were produced from naturally processed beans subjected to solid-state fermentation for more than 24 hours. In summary, the study suggests that the fermentation process is essential to modulate the quality of coffee and consequently increase its acceptability by consumers.
References: Wang et al., Food Chemistry: X, 23, 2024, 101684; L.C.F. Silva et al., Foods, 13, 2024, 1-18.
