Influence of storage time and color of light on photooxidation in cheese: A study based on sensory analysis and fluorescence spectroscopy

The sensitivity of front-face fluorescence spectroscopy to determine light-induced sensory changes in Jarlsberg cheese was elucidated. The cheese was exposed to white fluorescent light from 0 to 48 h, followed by fluorescence (380 nm excitation) and sensory analysis. Significant changes in sensory properties occurred after 4 h of exposure, while spectral changes could be measured after 30min. Correlations between fluorescence spectra and sensory properties were generally high (E0.9). Sensory response to exposure to light of equal intensity, but of different colors was also investigated. Violet and white light resulted in the worse quality degradation, while green light gave least adverse effects. No significant (p40:05) sensory difference between exposure to red and blue light was observed. Photoinduced changes by red, orange, and yellow light are ascribed to light degradation of porphyrins and chlorins, while for violet, blue, and green light, the degradation of riboflavin is probably also involved. r 2005 Elsevier Ltd. All rights reserved.