Influences of storage time and temperature on the xanthophyll content of freeze-dried egg yolk

The influences of storage time, temperature (−18 or +20 °C, both in the dark), and prior pasteurisation on the xanthophyll content of freeze-dried egg yolk were investigated. After six months of storage, the synthetic xanthophylls all-E-canthaxanthin and β-apo-8-carotenoic acid ethyl ester showed considerably higher stability (with losses of 19–34%) than did the natural pigments all-E-lutein and all-E-zeaxanthin (losses of 59–69%). At all stages of storage, the xanthophyll contents of unpasteurised and previously pasteurised samples did not differ significantly, and no obvious influence of storage temperature was observed. With respect to xanthophyll content, the results suggest that there is no necessity for low-temperature storage of freeze-dried egg yolk.