Juice components and antioxidant capacity of citrus varieties cultivated in China Guihua Xu a,b , Donghong Liu a , Jianchu Chen a , Xingqian Ye a, * , Yaqin Ma a , John Shi c a Department of Food Science and Nutrition, Zhejiang University, KaiXuan Road 268#, Hangzhou 310029, China b Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China c Food Research Center, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada Received 9 April 2007; received in revised form 5 June 2007; accepted 5 June 2007 Abstract Juices from fifteen citrus varieties (seven mandarins, four sweet oranges, one lemon, one grapefruit, and two pummeloes) of China were investigated mainly on quality parameters, total carotenoid, phenolic compounds (total phenolics, flavanone glycosides (FGs), and phenolic acids), and antioxidant capacity (ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay). Among the fifteen varieties, Bendizao had the highest content of total carotenoid (10.02 mg/L), Satsuma had the highest content of narirutin (288.12 mg/L), Yinzaocheng had the highest content of hesperidin (533.64 mg/L), and Huyou had the highest con- tent of naringin (348.53 mg/L), neohesperidin (265.25 mg/L) and total FGs (746.08 mg/L). As for total phenolic acids, Liubencheng had the highest content (72.61 mg/L). Hybrid 439 achieved the highest AA content (631.25 mg/L), and the highest total phenolics (1555.49 mg/L) and the greatest inhibition of DPPH radical (61.62%). Hamlin had the highest ascorbic acid equivalent antioxidant capacity (AEAC: 899.31 mg/L) determined by FRAP assay. Correlation coefficients of AA, total phenolics (gallic acid equivalent), FRAP (AEAC), DPPH (I%), total FGs and total phenolic acids indicated that AA played a major role for the antioxidant capacity of citrus juices, and phenolics also played an important role, which may be mainly ascribed to FGs, whilst phenolic acids seemed to play a minimal role. Furthermore, Huyou and Hybrid 439 were considered two valuable varieties from the view of antioxidant capacity and nutrition. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Citrus juices; Phenolic acids; Flavanone glycosides; Ascorbic acid; Antioxidant capacity 1. Introduction Citrus fruits not only have their delicious flavors but also have their antioxidant capacity with health benefits (Morton, Caccetta, Puddey, & Croft, 2000; Pellegrini et al., 2003). It’s well known that vitamin C and carote- noids are abundant in some citrus fruits (Dhuique-Mayer, Caris-Veyrat, Ollitrault, Curk, & Amiot, 2005), thus they are very beneficial to human health. In recent years, more attentions had been paid on phenolic compounds of citrus fruits, and some publications have suggested they might play an important role on the antioxidant capacity of citrus fruits (Gorinstein et al., 2004a; Rapisarda et al., 1999; Wang, Cao, & Prior, 1996). Dietary phenolic compounds of citrus fruits include flavonoids and phenolic acids (Bal- asundram, Sundram, & Samman, 2006). Generally, FGs dominate in citrus flavonoids, which were summarized recently by Peterson (Peterson et al., 2006a; Peterson et al., 2006b). Furthermore, narirutin, hesperidin, naringin and neohesperidin are the major FGs (Rouseff, Martin, & Youtsey, 1987). On the other hand, phenolic acids exist 0308-8146/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2007.06.046 Abbreviations: TSS, total soluble solids; TA, total acidity; AA, ascorbic acid; AEAC, ascorbic acid equivalent antioxidant capacity; HPLC–PDA, high-performance liquid chromatography–photodiode array detector; F- Gs, flavanone glycosides; FRAP, ferric reducing antioxidant power; DP- PH, 2,2-diphenyl-1-picrylhydrazyl; GAE, gallic acid equivalent. * Corresponding author. Fax: +86 571 86971165. E-mail address: psu@zju.edu.cn (X. Ye). www.elsevier.com/locate/foodchem Food Chemistry 106 (2008) 545–551 Food Chemistry