Rapport

A sensitive and rapid gas chromatographic method was developed for the separation and quantitative determination of non-volatile acids in coffee. The major acidic, chlorogenic and neochlorogenic acids components in coffee were identified as 3-caffeoyl-and 5-caffeoyl-quinic acids respectively. The less abundant acids were 4-caffeoylquinic acid and the isomeric "isochlorogenic acids" 3,4- 3,5- and 4,5- dicaffeoylquinic acid. The determination of these acids could serve as a quality control method for green and roasted coffee, and perhaps contribute to a better understanding of the chemical changes occurring during roasting. The date presented in this paper will be limited to the analysis of the mono- and di-caffeoylquinic acids. The method involves the neutralization of the coffee beverage with alkali, precipitation of high molecular weight materials with isopropanol and Lyophillization of the supernatant liquid. The dried product is acidified with formic acid, silylized with either hexamethyldisilazane or bis (trimethylsilyl) acetamide and the product analysed by gas chromatography. By using a temperature programmed gas chromatograph equipped with a flame detector, a 100 ft. of 0.025" capillary column coated with SE-54, the various isomers

Bibliographic Details

Main Authors:	84236 Kung, J.T., 114356 Ryder, W.S., 66759 Feldmann, J.R., 3180 Association Scientifique Internationale du Café, París (Francia), 32930 3. Colloque International sur la Chimie des Cafés Verts, Torrefies et Leur Derives Trieste 2-9 Jun 1967
Format:	biblioteca
Published:	París (Francia) 1968
Subjects:	ANALISIS QUIMICO, CROMATOGRAFIA, PROPIEDADES FISICO-QUIMICAS,
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