Microscopic analysis of aroma chemical distribution on fibers.: I.: cis-3-hexenyl salicylate

The distribution of aroma chemical cis-3-hexenyl salicylate, on both longitudinal and cross-sectional fiber directions, was identified through backscattered electron microscopy and X-ray microanalysis including X-ray spectrum and X-ray map. Three fibers-cotton, lyocell, and polyester [poly(ethylene terephthalate) (PET)]-were used as substrates to evaluate the influence of fiber physical/chemical nature on the distribution of cis-3-hexenyl salicylate. It was found that the distribution of cis-3-hexenyl salicylate on the external and internal fiber surfaces correlated strongly with the chemical structure, roughness, and both pore and capillary structure of the textiles. cis-3-Hexenyl salicylate distributed through the whole cotton fiber cross section with higher concentrations in lumen and crenulations, whereas it distributed relatively uniformly in the surface and cross section of lyocell fiber. This is believed to relate to the macro- and micropores, macroscopic roughness, and the presence of a larger number of polar groups for these cellulose fibers. In contrast, cis-3-hexenyl salicylate accumulated at a few spots on the fiber surfaces of PET and in interfiber spaces of closely packed fibers, attributed to lower polarity, round cross-sectional shape, smooth surfaces, and fewer voids of the PET fiber structure. (C) 2004 Wiley Periodicals, Inc.