Industrial Crops and Products 64 (2015) 97–104 Contents lists available at ScienceDirect Industrial Crops and Products jo ur nal home p age: www.elsevier.com/locate/indcrop Phenolic content and antioxidant activity of cactus (Opuntia ficus-indica L.) flowers are modified according to the extraction method Imene Ammar a,∗ , Monia Ennouri a,b , Hamadi Attia a a Alimentary Analysis Unit, National Engineering School of Sfax, BPW 3038 Sfax, Tunisia b Higher Institute of Applied Sciences & Technology of Mahdia, Sidi Messaoud 5111, Mahdia, Tunisia a r t i c l e i n f o Article history: Received 21 July 2014 Received in revised form 13 November 2014 Accepted 14 November 2014 Keywords: Antioxidant Flowers Opuntia Extraction Solvent a b s t r a c t The effect of different extracting solvents used by two methods on the total polyphenols and flavonoids contents of Opuntia ficus-indica flowers was studied. The antioxidant activity of these extracts was inves- tigated by using DPPH radical scavenging, reducing power and -carotene bleaching assays. The results showed that extracts exhibited different levels of polyphenols contents and antioxidant activity. Thus, solvents with different polarities had significant effect on antioxidant activity. The methanolic and aque- ous extracts proved best in terms of high extraction of phenolic compounds and antioxidant activity. Moreover, it can be concluded that extracts obtained by Soxhlet method were the most interesting in terms of antioxidant activity and proved that polyphenols responsible for the antioxidant activity of O. ficus-indica flowers are thermostable. These results showed that O. ficus-indica flowers could be a potential natural source of antioxidants that can be used in food and nutraceutical applications. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Natural products extracted from plants which belong to the Cac- taceae family have been widely used in folk medicine, in food and pharmaceutical field. One important genus in this family is Opuntia spp., with more than 200 species, mainly growing wild in arid and semi-arid regions, where the production of more succulent food plants is severely limited (Stintzing and Carle, 2005). Opuntia was shown to be rich in antioxidant compounds such as polyphenols, flavonoids, betaxanthin and betacyanin (Tesoriere et al., 2004a). Hence, the various parts of cactus plant (pulp, peel, seeds and cladode) have revealed notable antioxidant activities (Galati et al., 2003; Tounsi-Saidani et al., 2011; Valente et al., 2010). In addition, numerous studies have demonstrated the beneficial effects of phenolics and antioxidants of Opuntia (Chaalal et al., 2013; Dok-Go et al., 2003; Osorio-Esquivel et al., 2011; Siriwardhana and Jeon, 2004; Siriwardhana et al., 2006; Tesoriere et al., 2004b). Flowers from different plants’ have wide medicinal proper- ties and they are recognized as having antioxidant potentialities (Guimarães et al., 2013; Jo et al., 2012; Li et al., 2014; Onanong et al., 2011; Shyu et al., 2009). Nevertheless, literature reports few data ∗ Corresponding author. Tel.: +216 22 183 620; fax: +216 74 221 160. E-mail address: imene ammar@yahoo.fr (I. Ammar). regarding phytochemicals and antioxidant activities of Opuntia flower. Alimi et al. (2011) report the antioxidant and antiulcero- genic activities of methanolic extract of Opuntia ficus-indica inermis flowers. However, there are no studies dealing with the influence of different extraction solvents and techniques on the contents of nat- ural antioxidants in Opuntia flowers extracts. Thus, there is a need to further investigate the extraction of bioactive components from Opuntia flowers. In fact, the efficiency of extraction is affected by several factors; the most important are the type of solvent and the extraction method. Based on these statements, it can be concluded that it is very important to choose the appropriate method for the extraction of bioactive compounds from plants. Soxhlet extrac- tion is recognized as having a good reproducibility and efficiency, and less extract manipulation over other novel extraction methods (Wang and Weller, 2006). Indeed, the extraction by maceration and Soxhlet extraction has generally wide industrial applications. That is why we have selected these two methods in the present study for the extraction of phytochemicals from O. ficus-indica flowers. In this context, the present study aimed firstly to investigate phy- tochemicals contents of O. ficus-indica flowers extracts and then to evaluate their antioxidant activities using three in vitro tests; DPPH radical scavenging activity, reducing power and -carotene bleaching assays. We target to provide an appropriate base for fur- ther exploitation of these flowers as a source of natural antioxidant for food and nutraceutical applications. http://dx.doi.org/10.1016/j.indcrop.2014.11.030 0926-6690/© 2014 Elsevier B.V. All rights reserved.