Light-induced changes in semi-hard cheese determined by fluorescence spectroscopy and chemometrics

The impact of modified atmosphere packaging and different storage conditions on light-induced oxidation of sliced Havarti cheese has been evaluated by fluorescence spectroscopy. Data were analyzed with principal component analysis (PCA) and 50–50 MANOVA showing effects of storage in light or dark, light source (yellow or white light), light intensity, residual oxygen level, headspace volume, and storage time. No effect of storage temperature was noted. The PCA gave three components. One of these indicated a decrease in riboflavin content, which was seen only for samples exposed to white light. Another component denoted the variation in spectra below 500 nm probably due to formation of fluorescent oxidation products. The third component described the variation above 600 nm, which is ascribed to photodegradation of porphyrins. The porphyrins were degraded with storage time for both light sources.