Multivariate analyses of a wide selection of orange varieties based on carotenoid contents, color and in vitro antioxidant capacity.

Carotenoids, color and in vitro antioxidant capacity were analyzed in twenty-two genotypes of oranges produced in Spain in two consecutive seasons. The colorless carotenoids phytoene and phytofluene were also analyzed. An important influence of the genotype on the carotenoid profile was observed. In most genotypes, such profile was characterized by the predominance of xanthophylls (82.7-93.0%), except in Cara Cara, with a higher proportion of carotenes (around 70.0%). β-cryptoxanthin was the predominant carotenoid in Rohde late and Ambersweet. The samples with the lowest carotenoid contents were the ones exhibiting the lowest Trolox Equivalent Antioxidant Capacity (TEAC) and vice versa. A formula obtained by multiple regression is proposed to estimate the TEAC value from the carotenoid content. No significant correlation between TEAC values and color coordinates were obtained, suggesting that color parameters are not good predictors of TEAC values. Lastly, the samples could be classify with a high rate of success (>90%) by Linear Discriminant Analysis based on color and carotenoids.