Headspace Gas Chromatographic Analysis on Aroma of Coffee Bevenage

Studies on anoma of coffee Part IV

Abstract

An internal standard method for the gas chromatographic headspace analysis on the aroma of coffee brew was developed as follows: Five grams of ground coffee was weighed into a 130ml conical flask, and 50ml of the internal standard solution(sec-butanol, 2.5μl/50ml H₂O) was added. The flask was shut up with a silicon rubber having a headspace gas sampling device and incubated at 20°C for 90 min. Zero point five ml of the headspace gas was applied to a gas chromatography. (1)A linear relationship existed between the amount of internal standard and peak area. (2)Ground coffee adsorbed the internal standard in proportion to its concentration. The adsorbed amount was ca. 6%.(3)The reproduci-bilities(for quantitative analysis of the aroma constituents in the headspace gas)ranged from 2.2 to 9.6% based on the coefficient of variation.