Fluorescence detection in aldehyde containing model systems: Relationship with fish deterioration.

Abstract

In previous studies interaction compounds formation was accomplished by fluorescence detection at different excitation/ emission wavelength maxima during fish processing. A fluorescence shift towards higher wavelength maxima was then obtained as a result of damage increase. In the present work, different aldehydes were tested in order to compare their ability in producing fluorescent compounds with similar properties to the ones obtained during fish processing. Aldehydes (formaldehyde, FA; acetaldehyde, AcH; propanal, Pr; hexanal, Hex; 2-hexenal Hx; benzaldehyde, BzH) were reacted in model systems with sardine (Sardina Pilchardus) muscle and with n-propylamine at 30°C in dark during 25 days. A fluorescence shift was detected for all the aldehydes investigated as long as the reaction time increased. Great differences were observed between aldehydes, according to their chemical structure and reactivity. A sharp shift was detected for Hx and AcH, while little changes were observed in the cases of FA and BzH. As in the case of fish processing, Pr and Hex showed an increasing ratio between fluorescences detected at 393/463 nm and 327/415 nm as long as the reaction time increased.