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J Agric Food Chem

Title:		Wavelength dependence of light-induced lipid oxidation and naturally occurring photosensitizers in cheese
Author(s):		Andersen CM; Andersen LT; Hansen AM; Skibsted LH; Petersen MA;
Address:		"Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark. cma@life.ku.dk"
Journal Title:		J Agric Food Chem
Year:		2008
Volume:		20080215
Issue:		5
Page Number:		1611 - 1618
DOI:		10.1021/jf072672f
ISSN/ISBN:		0021-8561 (Print) 0021-8561 (Linking)
Abstract:		"Degradation of the potential photosensitizers, riboflavin, chlorophyll, and porphyrin, in Danbo cheese by monochromatic light of wavelength 366, 436, or 546 nm was studied. Three cheeses were investigated, two conventional (16% fat and 25% fat) and one 'organic' (25% fat). The effect of illumination was measured by fluorescence spectroscopy and analyzed using multiway and multivariate data analysis. Riboflavin was found to degrade only by 436 nm light, whereas chlorophylls and porphyrins also were influenced by 436 and 546 nm light. The organic cheese had the largest chlorophyll content both before and after similar light exposure, and no change in chlorophyll of this cheese was observed for any of the illumination wavelengths. Upon light exposure of the cheeses, volatile compounds were formed, as analyzed by gas chromatography-mass spectrometry (GC-MS). The relative concentrations of methyl butanoate, 1-pentanol, benzaldehyde, 2-butanone, 2-heptanone, and butyl acetate were found to weakly correlate with the surface fluorescence intensity. 1-Pentanol and the ketones are secondary lipid oxidation products, consistent with a chemical coupling between photosensitizer degradation and formation of volatile lipid oxidation products"
Keywords:		Cheese/analysis/*radiation effects/standards Chlorophyll/chemistry/radiation effects Fats/*chemistry Food Handling/*methods Food Packaging/methods Light/*adverse effects Lipid Peroxidation Oxidation-Reduction *Photochemistry Porphyrins/chemistry/radiation;
Notes:		"MedlineAndersen, Charlotte M Andersen, Lene T Hansen, Anne Mette Skibsted, Leif H Petersen, Mikael A eng Research Support, Non-U.S. Gov't 2008/02/16 J Agric Food Chem. 2008 Mar 12; 56(5):1611-8. doi: 10.1021/jf072672f. Epub 2008 Feb 15"