Spectral Differentiation of β-Carotene Accumulation Patterns in Skin Tissues with Distinct Levels of Constitutive Pigmentation.

The accumulation of β-carotene in human skin has been connected to various forms of protection offered by this ubiquitous carotenoid, from the absorption of ultraviolet radiation to the neutralization of reactive oxygen species. These protective mechanisms, in turn, are likely to be associated with the accumulation pathways of this pigment, via the top (epidermal) and/or the bottom (dermal) cutaneous tissues. The differentiation of the distinct accumulation patterns of β-carotene through noninvasive methodologies is still an open problem, however, notably for skin specimens with relatively high levels of constitutive pigmentation. In this paper, we address this open problem by proposing and evaluating three spectral tests based on carotenemia-elicited variations in skin reflectance within the red end of the visible spectrum. Their efficacy is examined using a first-principles in silico experimental framework grounded on measured data for different skin specimens. The outcomes of our investigation indicate that the use of such a spectral testing approach can lead to reliable and cost-effective differentiation assessments of distinct β-carotene accumulation patterns in skin tissues.