Fluorescence fingerprints as a rapid predictor of the nutritional quality of processed and stored foods

Foods are complex mixtures of macro- and micronutrients, which interact leading to oxidation, glycation and hydrolysis upon heating (sterilization, cooking) and storage. The nutritional quality and safety is consequently affected justifying the need for accurate monitoring of the evolution of the food composition during processing and in product shelf life. Classical chromatographic analysis as well as newly proposed rapid methods based on fluorescence spectrometry analyses are applied in the present study on (i) fresh and stored carrots, (ii) infant formula resembling model, (iii) heated rapeseed oil, and (iv) wheat biscuits. Fluorescence fingerprints addressing modifications in the product composition during processing were recorded and analyzed by means of chemometric methods. Fluorescence, recorded in a front-face mode on intact and crushed food, or product extracts, is very sensitive to pertinent physicochemical changes induced by heat treatment or storage. Results show the potential of non-destructively applied fluorescence spectrometry for measuring vitamin E in carrots, carboxymethyllysine in powdered infant formula models, polar compounds in rapeseed oil and hydroxymethylfurfural in biscuits. This paper presents the potential of fluorescence as a global approach of the quality of processed food. © 2004 Czech Academy of Agricultural Sciences. All rights reserved.