Varietal and interspecific influrence on micronutrient contents in citrus from the Mediterranean area

To specify the genotypic variation of Mediterranean Citrus juices, the contents of carotenoids, flavonoids, and vitamin C were determined by high-performance liquid chromatography. A selection of orange varieties and Mandarin species from the Mediterranean area (Citrus sinensis, Citrus deliciosa Ten, and Citrus clementina Hort. ex Tan) was evaluated using carotenoid profiles and flavanones contents. Among the eight varieties of orange (Salustiana, Hamlin, Shamouti, Pera, Valencia, Maltaise, Sanguinelli, and Cara-cara) and two Mandarin species, only three cultivars (Pera, Sanguinelli, and Shamouti) and the two Mandarin species displayed a high content of vitamin A (374, 381, and 272 ER L-1 for the three orange cultivars and 1156 and 960 retinol equivalent (RE) L-1 for the Mandarins) due to a high content of [bêta]-cryptoxanthin. These same Citrus were also rich in hesperidin (502, 537, 552, 767, and 754 mg L-1, respectively). Principal component analysis allowed the Mediterranean orange varieties and Mandarin species to be differentiated on the basis of nutritional criteria. Strong correlations were observed between [bêta]-cryptoxanthin and hesperidin (r = 0.92) and between [bêta]-cryptoxanthin and [bêta]-carotene (r = 0.98). In contrast, vitamin C content was not correlated with carotenoids and flavanone glycosides. The Mandarin and orange group was quite distinct. The orange varieties could be divided in two groups. In addition, a diversity tree allowed a genetic approach to differentiating Citrus cultivars on the basis of Euclidian distances. This representation showed that the hybrid Clementine was nearer to its parent Mandarin than to its parent orange, suggesting that [bêta]-cryptoxanthin was a dominant genetic factor. With regard to vitamin A, Mandarin and its hybrid Clementine appeared to be the best Citrus species. (Résumé d'auteur)