Characterization of antioxidant compounds in Jaffa sweeties and white grapefruits

• Published in: Food chemistry 2004-03, Vol.84 (4), p.503-510
• Main Authors: Gorinstein, Shela, Cvikrová, Milena, Machackova, Ivana, Haruenkit, Ratiporn, Park, Yong-Seo, Jung, Soon-Teck, Yamamoto, Kazutaka, Leticia Martinez Ayala, Alma, Katrich, Elena, Trakhtenberg, Simon
• Format: Article
• Language: English
• Subjects: Antioxidant compounds; Antioxidative activities; Biological and medical sciences; Citrus fruits; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/S0308-8146(03)00127-4

Antioxidant compounds and the antioxidative activities of new Israeli citrus fruit sweetie [(Oroblanco, pummelo-grapefruit hybrid ( Citrus grandis×C. paradisi)] were compared with the better-known white grapefruit. Total and free phenols were determined with the Folin–Ciocalteu reagent, phenolic acids (free, esters and glycosides) by HPLC analysis and anthocyanins spectrophotometrically. The antioxidant activities were estimated with two scavenging radicals: 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonate)- (ABTS) and nitric oxide (NO). Free radical scavenging properties of sweetie and grapefruit were evaluated by β-carotene bleaching (β-carotene). The results of kinetic reactions showed that both fruits differed in their capacities to quench these radicals and sweetie showed more antioxidative activity than grapefruit. Trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were more abundant in grapefruits than in sweeties. High correlation was observed between antioxidative activities and phenols ( R 2=0.94). Both fruits have high concentrations of natural antioxidants with high antioxidative activities. Phenol content and the antioxidative potential are significantly higher in sweetie than in grapefruit. The higher antioxidant capacity of sweetie could make these new kinds of citrus fruits preferable for diets. In summary, the studied citrus fruit has high total phenolics and high antioxidant activities in vitro. Consumption of this fruit may contribute to an adequate intake of antioxidant phytochemicals.