Content and antioxidative capacity of carotenoids, α-tocopherol and polyphenolics in compartiments of tomatoes grown under saline conditions

Saline growing conditions influence the inner quality of tomato fruit. As part of it the content of carotenoids and their anti-oxidative capacity is significantly enhanced by rising salinity levels. Our aim was to investigate to what extent this increase can be attributed to different compartments of the fruit quantitatively, i.e. to the peel (epidermal structure/exocarp) and the pulpae (endo- and meso-carp). We could show that the antioxidative capacity is significantly higher in the peel compared to the flesh and that rising salinity lead to increasing AC in the peel both for carotenoids and polyphenolics. Regarding the pulpae, only the highest salinity level improved AC. Likewise, analysis of the most important lipid-soluble antioxidants, i.e. P-carotene, lycopene and alpha-tocopherol revealed increasing concentrations. This increase however was much more pronounced in the peel compared to the fruit. Examination of the polyphenolic content by means of Folin-Ciocalteu revealed only slight increases in the flesh/pulp with rising salinity, in the peel the polyphenolic content increased stronger.