Chemical-Technological Aspects for Concentration of Plant Aromas

Mechanism of formation of volatile compounds by thermal degradation of carotenoids in aqueous medium. 1. .beta.-Carotene degradation

“…The volatile compounds isolated under these conditions are given in Table I. Most of the components have been previously identified in the volatile fraction produced by thermal degradation of /3-carotene in the solid state or in solution (La Roe and Shipley, 1970; Schreier et al, 1979;Drawert et al, 1981;Kawakami, 1982). On the other hand, decanal, 4-ethylbenzaldehyde, and cetoisophorone (2,6,6-trimethyl-2-cyclohexene-l,4dione) were identified for the first time among the compounds produced during heat treatment of /3-carotene and 2,6-dimethyldecahydronapthalene, and 2-hydroxy-2,6,6trimethylcyclohexanone was tentatively identified on a mass spectral basis (Stenhagen et al, 1974;Viani et al, 1969).…”

Mechanism of formation of volatile compounds by thermal degradation of carotenoids in aqueous medium. 2. Lycopene degradation

“…Under these conditions quantitative determinations were performed with use of only solvent extracts. Among the compounds identified, only three of them, 2-methyl-2-hepten-6-one, geranial, and neral, have been reported as degradation products of lycopene (Stevens, 1970;Drawert et al, 1981). The other compounds, 5-hexen-2-one, hexane-2,5-dione, 6-methyl-3,5-heptadien-2-one, geranyl acetate, and pseudoionone, were identified or tentatively identified for the first time among the volatile compounds produced by thermal degradation of lycopene.…”

“…To our knowledge, only one work (Drawert et al, 1981) was devoted to the study of pure lycopene degradation in the solid state; 2-methyl-2-hepten-6-one was identified in the volatile fraction isolated.…”

Study on the Influence of Pasture on Volatile Fraction of Ewes’ Dairy Products by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

“…The reason of the presence of toluene in milk and cheese remains unclear. Moio et al (1993b), referring to the research of Drawert et al (1981), who described a natural origin of this compound as a degradation product of β-carotene, hypothesized a direct transfer from forage into milk. The recent researches of Spinhirne et al (2003Spinhirne et al ( , 2004, who found toluene in the volatile profile of ruminal cultures (2003) and bovine breath (2004), seemed to support this assumption.…”