Thermostability and structural evolution of silica xerogel matrix with embedded carrot juice

Stabilization of β-carotene embedded in a silica matrix and study of its physical properties

“…Previous works reported the study of extracts of green-leaves and carrots components embedded in a silica matrix [9,18]. These results show that chlorophylls and carotenoids species can be stabilized within a silica matrix together with the organic components having in green plants and carrots.…”

“…Also, the contribution observed at 1385 cm −1 in the RT sample was identified as the π-d interaction between the pyrrole-type ring of the βC and the empty d orbital of the silica. This interaction is the main responsible for stabilizing the conjugated double bond of the βC chains and assures its incorporation with the silica matrix [9,29]. Then, resulting from a mutual interaction among the pure βC and the silica, the structure of the βC is stabilized, avoiding its degradation under light exposure and ambient conditions.…”

“…In this sense, there are very few works studying the thermostability of organic molecules embedded in a silica matrix. We reported the stabilization of carotenoid species obtained directly from carrots when they were integrated into a silica matrix, prevalecting the βC even at high calcination temperatures [9]. Also, this organic multi-component system induces a silica crystallization above 800°C from α-quartz to αand β-cristobalites, with traces of β-tridymite and stishovite-type structure [9].…”

“…Then, to take advantage of the βC exceptional biomedical properties needs developing advanced methods allowing its stabilization. In this sense, some theoretical and experimental works report alternatives to protect the βC from ambient degradation, among that, stand out the incorporation of the β-carotene inside of carbon nanotubes [8], or the stabilization of carotenoids species obtained directly from carrot juice [9]. Currently, no further studies are dealing with the thermal stabilization of the βC.…”

“…Then, before to think using the βC in the design of technological devices or for biomedical applications, it is of great importance protecting the βC from thermal and ambient degradation. [8,9,14]. Also, the design of composites based on plant molecules together with an inorganic component requires the understanding of structural interactions manifested among the biomolecules and the matrix, as well as of its evolution under operation conditions.…”