Cafestol and kahweol content in different specialty coffee brews: Exploration by NMR analysis and evaluation of brewing parameters

Cafestol and kahweol, two coffee diterpenes known for their health effects, were quantified in cups of Kenya specialty coffee prepared using eight different brewing methods: AeroPress, Chemex, Clever, V60, Moka, Ibrik, Pure Brew, and French press. High-resolution Nuclear Magnetic Resonance (NMR) spectroscopy was employed for this analysis, involving a straightforward sample preparation procedure with only an extraction step for lipid compounds. Statistical tools were utilized to examine the correlation between diterpene concentrations and each extraction feature, with a focus on the impact of brewing parameters. The results indicate that unfiltered brewing methods produce coffee with high concentrations of diterpenes, whereas paper-filtered methods result in significantly lower concentrations. The findings suggest that these compounds are present in the coffee cup as part of the suspended solids, and that filtration, pressurization, and coffee powder particle size are crucial parameters influencing their concentration.