Coffee Biotransformation in Volcanic Process: A Chemical and Sensory Analysis.

Area of Science:

• Agricultural Science
• Food Science
• Biotechnology

Background:

• Volcanic fermentation is a novel post-harvest coffee processing technique.
• It involves creating
• volcanoes
• (conical mounds) to optimize biotransformation.
• This method aims to enhance the chemical composition and sensory qualities of coffee.

Purpose of the Study:

• To investigate the impact of different volcanic fermentation methods on coffee's chemical and sensory attributes.
• To analyze variations in sugars, organic acids, and alcohols under distinct fermentation conditions.
• To evaluate color differences and sensory profiles of coffee processed using various volcanic fermentation techniques.

Main Methods:

• Four volcanic fermentation methods were tested: asphalt patio (E1), on pallets (E2), in steel containers under sun (E3), and in shade (E4).
• Chemical composition analysis included sugars (sucrose, glucose, fructose), organic acids (citric, malic, succinic, lactic, acetic), and alcohols (glycerol, ethanol).
• Color differences (ΔE) and sensory analysis were performed on the fermented coffee samples.

Main Results:

• Volcanic fermentation produces high-quality specialty coffee with varied acid and alcohol profiles.
• Specific fermentation methods influenced the sensory characteristics of the coffee beverage.
• pH and soluble solids remained consistent across methods, indicating robust microbial fermentation.
• Key sensory descriptors included chocolate, citrus, honey/molasses, caramel, floral, and brown sugar.

Conclusions:

• The volcanic fermentation method significantly impacts the chemical and sensory quality of fermented coffee.
• Despite variations in acid/alcohol profiles, the core fermentation process is consistent regardless of solar exposure.
• This technique offers a pathway to producing specialty coffees with diverse and desirable flavor profiles.