DEVELOPMENT OF A FLUORESCENCE SENSOR TO MONITOR LIPID OXIDATION .1. FLUORESCENCE-SPECTRA OF CHITOSAN POWDER AND POLYAMIDE POWDER AFTER EXPOSURE TO VOLATILE LIPID OXIDATION-PRODUCTS

The fluorescence spectra of chitosan and polyamide power after exposure to lipid oxidation volatiles were obtained by solid-sample fluorescence spectrophotometry. Chitosan powder fluoresced after exposure to the volatile oxidation products from oxidizing methyl arachidonate and methyl linolenate. Chitosan powder also fluoresced after exposure to pure malonaldehyde vapor. Chitosan fluorescence after exposure to volatile malonaldehyde had an excitation maximum at 395 nm and an emission maximum at 460 nm. These wavelength maxima were similar to the fluorescence wavelength maxima of chitosan after exposure to the lipid oxidation volatiles. Chitosan did not fluoresce after exposure to hexanal and 2,4-decadienal at concentrations produced during methyl linoleate oxidation and appeared to be selective to malonaldehyde for fluorescence formation. Chitosan fluorescence spectra are compared to the fluorescence spectra of polyamide powder after exposure to lipid oxidation volatiles and after exposure to volatile malonaldehyde.