Characterization of Extra Early Spanish Clementine Varieties (Citrus clementina Hort ex Tan) as a Relevant Source of Bioactive Compounds with Antioxidant Activity

Abstract

The most relevant nutrients and bioactive compounds (soluble sugars, dietary fiber, ascorbic acid and organic acids, individual phenolic compounds, fatty acids, and tocopherols) as well as antioxidant activity have been characterized in three extra early varieties of clementine (Citrus clementina Hort ex Tan. Basol, Clemensoon and Clemenrubí) cultivated in Valencia (Spain). Clementines are a relevant source of bioactive compounds, such as vitamin C (values around 80 mg/100 g), allowing to satisfy the recommended daily intake with the consumption of a normal portion. Sucrose was the most abundant sugar, and potassium the main mineral while manganese was the least. Fat content was very low (<0.5 mg/100 g), with palmitic acid and α-tocopherol the most abundant fatty acid and vitamin E form, respectively. Flavonoids were the predominant phenolic compounds, with narirutin/naringin and (neo)hesperidin the best represented ones. The antioxidant capacity evaluated by reducing power, DPPH, and β-carotene bleaching inhibition assays was satisfactory with values similar to those reported in other citrus fruits. Thus, this fruit is a relevant source of bioactive compounds with antioxidant properties of interest for consumers and the food industry.

Phenolic and Carotenoid Profile of Lamb’s Lettuce and Improvement of the Bioactive Content by Preharvest Conditions

“…The mass spectral characteristics of compound 26 , with [M − H] − at m/z 609 and the main fragment at m/z 301 as a result of the loss of a rutinoside moiety (−308 Da), corresponded to hesperetin−7- O -rutinoside (hesperidin), which is a common flavanone in citrus fruits [ 55 ] but the only one we detected in lamb’s lettuce.…”

Effect of Rootstock and Harvesting Period on the Bioactive Compounds and Antioxidant Activity of Two Orange Cultivars (‘Salustiana’ and ‘Sanguinelli’) Widely Used in Juice Industry

“…If we take into consideration the total carotenoid content, we did not observe a correlation between both parameters. The different results observed and the non-correlation may be linked to the contribution of other antioxidant compounds in the hydrophobic fraction, such as tocopherols [60,61].…”

Novel Urinary Biomarkers of Orange Juice Consumption, Interindividual Variability, and Differences with Processing Methods

“…This is consistent with the reported higher content of polymethoxyflavones in commercial fresh and pasteurized juices than in gently hand-squeezed juice as polymethoxyflavones are associated with the flavedo oil and occur in the peel and not in the juicy parts of the fruit. 24 Sinapic acid derivatives (glucaric and galactaric acid esters) have been identified as characteristic hydroxycinnamates of the peel of citrus fruits 25 as well as the abscisic acid derivative dihydrophaseic acid. 25 This is consistent with the upregulation of sinapic acid 4′glucuronide and abscisic acid in the urine after the intake of processed orange juices.…”

“…24 Sinapic acid derivatives (glucaric and galactaric acid esters) have been identified as characteristic hydroxycinnamates of the peel of citrus fruits 25 as well as the abscisic acid derivative dihydrophaseic acid. 25 This is consistent with the upregulation of sinapic acid 4′glucuronide and abscisic acid in the urine after the intake of processed orange juices. This is probably produced by the close contact of the juice with the orange peel during processing.…”