The composition of wax and oil in green coffee beans

Methods for the isolation of wax and oil from green coffee beans were studied and a method for the quantitative extraction of coffee oil from the beans was introduced. Coffee wax, coffee oil and wax-free coffee oil as well as the unsaponifiable matter prepared from each were fractionated by column chromatography. The chemical composition of the fractions was studied by thin-layer chromatography, gas-liquid chromatography, ultraviolet, infrared, nuclear magnetic resonance and mass spectrometry. The results include qualitative and quantitative data on (1) the total fatty acid composition as well as the composition of the fatty acids in triglycerides and diterpene alcohol esters, (2) the positional distribution of the fatty acids in the triglycerides, (3) the unsaponifiable matter and (4) Nβ -alkanoyl-5-hydroxy-tryptamines (C-5-HT) and other C-5-HT-like phenolic compounds.The unsaponifiable matter (3) was fractionated into diterpene alcohols, sterols and hydrocarbons (including squalene and n -alkanes from C 16 to C 31 ). Moreover the presence of α-tocopherol and (β+ γ)-tocopherol in green coffee beans was described for the first time.In view of the results of this study the removal of coffee wax by industrial processes, which are claimed to have a beneficial effect on the digestibility of coffee, was discussed. The current literature on the lipids of green coffee beans was extensively reviewed