Flavour retention by lipids measured in a fresh cheese matrix

Interactions between lipids and several aroma compounds (aldehydes, methylketones, esters, and dimethyldisulfide) were studied in a real food system composed of fresh cheese, triolein, and water. The concentration of 'free' ligands was measured with a dynamic headspace-gas chromatographic system. From our results, we conclude that retention of all flavouring molecules increases with the amount of triolein. This phenomenon is highly influenced, however, by the structure of the aroma compound, as demonstrated by RP-HPLC lipophilicity determinations. Within the same chemical family there exists a linear relationship between the lipophilicity index k(w) and retention, indicating that this physicochemical property should be taken into account in choosing the best internal analytical standard. (C) 1998 Published by Elsevier Science Ltd. All right reserved

Determination of the lipophilicity of aroma compounds by RP-HPLC

The lipophilicity of aroma compounds was measured by reversed-phase high pressure liquid chromatography (RP-HPLC). The lipophilicity index provided by this technique is the capacity factor, log k(w), obtained by extrapolating series of log k values measured at various proportions of methanol in the methanol-water mobile phase. This article lists the log k(w) capacity factors of 96 flavouring compounds belonging to various families (pyrazines, thiazoles, other heterocyclic compounds, alcohols and phenols, ketones, caters, aldehydes and sulphur compounds). (C) 1998 John Wiley & Sons, Ltd