Odour-active compounds in moderately roasted sesame

Aroma extract dilution analysis (AEDA) of an extract prepared from moderately roasted sesame (180°C; 10 min) revealed 41 odour-active volatiles, 31 of which could be identified by comparison of their mass spectra, retention indices, odour quality and odour threshold with reference compounds. Of the 18 aroma compounds showing very high Flavour Dilution factors in the range of 128-2048, 10 compounds [2-furfurylthiol, 2-phenylethylthiol, 2-methoxyphenol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 2-pentylpyridine, 2-ethyl-3,5-dimethylpyrazine, acetylpyrazine, (E,E)-2,4-decadienal, 2-acetyl-1-pyrroline and 4-vinyl-2-methoxyphenol] were quantified by means of stable isotope dilution assays and their odour activity values (OAV; ratio of concentration to odour threshold) were calculated. On the basis of high OAVs in oil, especially 2-acetyl-1-pyrroline (roasty), 2-furfurylthiol (coffee-like), 2-phenylethylthiol (rubbery) and 4-hydroxy-2,5-dimethyl-3(2H)- furanone (caramel-like) were elucidated as important contributors to the overall roasty, sulphury odour of the crushed sesame material.