Chromatographic Evaluation of CO₂-Controlled Fermentation Effects on the Sensory and Chemical Quality of Dry-Processed Coffees

As worldwide demand for premium-quality coffee grows, the fermentation process plays a critical role in the production of natural (dry-processed) coffees with distinct and appealing flavors and aromas. Improper fermentation conditions, however, can result in defects that negatively impact the quality of the coffee. The desire to nullify these defects inspired research aimed to compare various fermentation methods to produce natural coffees and evaluate their impact on both sensory attributes and chemical composition.

A research team comprised of researchers from SENA Technologies Center Agroindustriales (Cartago, Colombia) and the Universidad del Valle (Caicedonia, Colombia)evaluated five fermentation processes: exposure to air for 24 and 48 h, fermentation in sealed containers with CO₂ for 24 and 60 h, and a control with no fermentation. The total sugar content was measured using ultra-high-pressure liquid chromatography (UHPLC), fatty acids composition was analyzed using gas chromatography (GC), and chlorogenic acid content was determined using high-performance liquid chromatography (HPLC). A paper based on this research was published in The Scientific World Journal (1).

The dry fermentation coffee processing method, deeply rooted in coffee-producing regions, plays a crucial role in defining the physical, chemical, and sensory attributes of coffee, and has gained increasing significance because of its considerable impact on the final quality of the product (2). Studies have analyzed variations in fermentation conditions, methodologies, and their effects on parameters such as pH, acidity, volatile compounds, and antioxidant activity, as well as focused on the operational benefits of dry fermentation, highlighting the efficiency of the process in decreasing both time and costs (3).

In recent years, Colombia has recently seen a growing interest in the achievement of varied sensory profiles, which has driven increased attention toward dry-processed coffees which produce natural profiles (4). Many coffee fermentation processes, however, present an inadequate level of control, which leads to defects, inconsistencies in quality inconsistencies, and economic losses for the coffee grower, as well as the imposition of limitations on their accessing high-quality coffee markets (5).

Although there have been many advances in coffee fermentation research, previous studies have mostly been conducted under laboratory-controlled or wet fermentation conditions, which results in a limitation of their applicability to dry processing systems (6).

“There is still scarce empirical evidence on how modified-atmosphere fermentation, particularly with CO₂, affects the chemical and sensory quality of dry-processed coffees under real production settings,” the authors of this study noted in their paper (1). To address this gap, they added, “the present study evaluates the effects of different CO₂-based fermentation methods on sugars, chlorogenic acids, fatty acid composition, and sensory attributes, contributing to a more comprehensive understanding of controlled fermentation in natural coffee production” (1).

The research indicated that fermentation processes involving CO₂ demonstrated better sensory performance as opposed to treatments fermented in contact with ambient air for natural coffee production. “The fermentation and drying processes implemented in this research,” reported the authors of the article (1), “resulted in natural coffees free of sensory defects.”

The researchers stated it is crucial in future investigations to conduct chemical analysis evaluations which encompass a wider range of compounds to explain the differences observed in the sensory analysis (1).

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References

1. Moncayo-Palacios, M. F.; Muñoz-Carvajal, V. H.; Largo-Avila, E. et al. Impact of Coffee Cherry Fermentation Methods on the Quality Attributes of Dry-Processed Coffee. ScientificWorldJournal 2025, 2025, 4278424. DOI: 10.1155/tswj/4278424
2. Febrianto, N. A.; Zhu. F. Coffee Bean Processing: Emerging Methods and Their Effects on Chemical, Biological and Sensory Properties. Food Chem. 2023, 412, 135489. DOI: 10.1016/j.foodchem.2023.135489
3. Cavanagh, Q.; Brooks M. S.-L.; Rupasinghe H. P. V., Innovative Technologies Used to Convert Spent Coffee Grounds Into New Food Ingredients: Opportunities, Challenges, and Prospects. Future Foods 2023, 8, 100255. DOI: 10.1016/j.fufo.2023.100255
4. Osorio, V.; Pabón, J.; Shuler J. et al. Efecto de la combinación de procesos de secado en la calidad del café natural obtenido vía seca. Revista Cenicafé 2022, 73 (1), e73101. DOI: 10.38141/10778/73101
5. Puerta, G.; Echeverry J., Fermentación controlada del café: Tecnología para agregar valor a la calidad. Avances Técnicos Cenicafé 2015, 454, 1–12. DOI: 10.38141/10779/0454
6. Peñuela-Martínez, A. E.; Osorio-Giraldo, C. V.; Buitrago-Zuluaga, C. et al. Development of Fermentation Strategies for Quality Mild Coffee Production (Coffea arabica L.) Based on Oxygen Availability and Processing Time. Foods 2025, 14 (17), 3001. DOI: 10.3390/foods14173001