Gas Chromatographic Analysis of the Head Space Vapor on Black Tea Infusion

Abstract

An analytical method of the head space vapor on black tea infusion was investigated by means of gas-liquid chromatography. The procedures I of. the gas analysis : were as follows:
A hundred ml. of boiling water was poured on 30 g. black tea in a.200 ml. Erlenmeyer flask which was placed on a boiling water bath to keep a constant temperature. After standing for 6 minutes 10 ml. of the head space vapor on black tea infusion was injected into gas chromatograph (column : PEG-6000, column temp.: 80°C, He flow rate : 30 ml/min, detector : flame ionization system).
Legg-cut black teas stored for a year under various conditions were analysed by the above mentioned technique. Two components were noticed remarkably on the gas chromatograms, the one was increasing n-capronaldehyde and the other decreasing trans-2-hexenal (leaf aldehyde).
Scented black tea was also analysed and scenting compounds were detected distinctly on the gas chromatogram.