Carotenoid profiling of red navel orange "Cara Cara" harvested from five regions in China.

Understanding the composition and content of carotenoids in red-flesh navel orange "Cara Cara" cultivated in different regions is valuable for its nutrition assessment and fruit processing control. Herein, the carotenoids of "Cara Cara" fruits, harvested from five typical citrus growing regions of China, were identified and quantified by HPLC-DAD coupled with HPLC-DAD-APCI-MS/MS. In saponified extracts, 19 free carotenoids including 8 carotenes and 11 xanthophylls were identified. In unsaponified extracts, 83.83-93.83% xanthophylls were esterified and 19 esters were inferred, with the 9-cis-violaxanthin ester confirmed as the dominant component. The carotenoid contents showed difference among the "Cara Cara" fruits from different growing regions, which might be attributed to the local environmental conditions, and the temperature was found directly correlated with total carotenoids content of "Cara Cara". The data obtained in this study will facilitate the nutritional evaluation of "Cara Cara" and provide beneficial guidance for fruit processing.