Influence of Storage and Preservation Techniques on Egg-Derived Carotenoids: A Substantial Source for Cutaneous Antioxidants

Abstract

Antioxidants like carotenoids play a major role in the prevention of the destructive influence of free radicals in our skin. Carotenoids, as well as all other antioxidants, are substantial substances which must be supplied by nutrition. Resonance Raman spectroscopy (RRS) allows measurement of the carotenoid content of eggs, representing a rich carotenoid source in our nutrition. A previous study showed that eggs from organic production contain higher carotenoid levels in contrast to eggs from conventionally housed chicken. The uptake of these organically produced eggs led to an increased antioxidant concentration in the skin. In this study, the effects of different storage modalities, conservation techniques, and the effects of food processing on the carotenoid levels in eggs were investigated with RRS. Common storage modalities and preservation techniques showed only a limited influence on egg-derived carotenoid concentrations. However, a colder environment (at least for shell eggs) and high-pressure preservation had the best preservative influence on the carotenoid content. Surprisingly, food processing such as boiling increased the carotenoid concentration in eggs, whilst broiling destroyed the carotenoids almost completely. In conclusion, RRS is suitable for monitoring egg-derived carotenoid levels, and carotenoid levels in eggs are generally stable under common storage and preservation modalities. Boiling in contrast to broiling of eggs might be superior in terms of carotenoid preservation within food processing.

In vivo Tracking of DNA for Precise Determination of the Stratum Corneum Thickness and Superficial Microbiome Using Confocal Raman Microscopy

“…The aim of this study is to depth-dependently track the vibrational modes of DNA molecules [50] in the epidermis to determine the SC thickness in the FP region and to compare these results with the ones acquired by using the conventional water-derived SC thickness determination methods. This work also provides collective insight into the methodologies to determine the SC thickness by using CRM.…”