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Raman spectroscopy application in frozen carrot cooked in different ways and the relationship with carotenoids
Author(s) -
Camorani Paolo,
Chiavaro Emma,
Cristofolini Luigi,
Paciulli Maria,
Zaupa Maria,
Visconti Attilio,
Fogliano Vincenzo,
Pellegrini Nicoletta
Publication year - 2014
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7009
Subject(s) - carotenoid , raman spectroscopy , chemistry , isomerization , food science , steaming , analytical chemistry (journal) , chromatography , biochemistry , optics , physics , catalysis
Abstract BACKGROUND Raman spectroscopy, in its confocal micro‐Raman variation, has been recently proposed as a spatially resolved method to identify carotenoids in various food matrices, being faster, non‐destructive, and avoiding sample extraction, but no data are present in the literature concerning its application to the evaluation of carotenoid pattern changes after thermal treatment of carrots. RESULTS The effect of three cooking methods (i.e. boiling, steaming and microwaving) was evaluated on frozen carrot, comparing changes on carotenoid profiles measured by means of Raman spectroscopy with their high‐performance liquid chromatographic determination and colour. A more pronounced detrimental effect on carotenoids was detected in steamed carrots, in accordance with colour data. Conversely, boiling and, to a lesser extent, microwaving caused an increase in carotenoid concentration. Cooking procedures affected the Raman spectral features of carotenoids, causing a shift of vibration frequencies towards a higher energy, increase in the spectral baseline and peak intensities as well as a broadening of their width, probably in relation to the thermal degradation of longer carotenoids (i.e. the all‐ trans form) and the isomerization process. In particular, steamed samples showed a significantly higher increase of centre frequency, in accordance with a more pronounced isomerization and changes in colour parameters. CONCLUSION This work showed that the evolution of Raman spectral parameters could provide information on carotenoid bioaccessibility for carrots cooked using various methods. This paves the way for a future use of this technique to monitor and optimize cooking processes aimed at maximizing carotenoid bioaccessibility and bioavailability. © 2014 Society of Chemical Industry