Short communication Selenium content in seed, oil and oil cake of Se hyperaccumulated Brassica juncea (Indian mustard) cultivated in a seleniferous region of India Sumit K. Jaiswal a , Ranjana Prakash b , Raghunath Acharya c , Annireddy V.R. Reddy d , N. Tejo Prakash a,⇑ a Department of Biotechnology and Environmental Sciences, Thapar University, Patiala 147004, India b School of Chemistry and Biochemistry, Thapar University, Patiala, India c Radiochemistry Division, Mumbai, India d Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai, India article info Article history: Received 11 November 2011 Received in revised form 6 February 2012 Accepted 22 February 2012 Available online 3 March 2012 Keywords: Selenium Mustard Hyperaccumulation Neutron activation analysis abstract Selenium (Se) hyperaccumulated Indian mustard (Brassica juncea) cultivated in a seleniferous region of India was collected and quantified for Se levels using instrumental neutron activation analysis (INAA). The seeds were subjected to oil extraction using a conventional screw extractor and Se content was esti- mated in seed, oil and oil cake. High uptake of selenium by the mustard seeds occurred, which was pre- dominantly found to be retained and concentrated in the oil cake (143 ± 5.18 mg kg 1 ) when compared to seed before extraction (110 ± 3.04 mg kg 1 ) or oil (3.50 ± 0.66 mg L 1 ) after extraction. In conclusion, the study envisages application of Se-rich mustard oil or cake as sources of chemotherapeutic isoselenocya- nates and exploitation of their bioactivity. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction We can use crop plants with an augmented capacity to accumu- late minerals to aid sustainable agriculture and to improve human health through balanced mineral nutrition (Guerinot & Salt, 2001). This requires an understanding of how plants accumulate and store minerals. Hyperaccumulation is the ability of certain plants to accumulate extraordinarily high levels of metals and metalloids, even from soil containing corresponding lower concentrations (Baker & Brooks, 1989). Most plants contain only low foliar concen- trations of Se, of less than 25 mg kg 1 dry weight, and rarely ex- ceed 100 mg kg 1 dry weight even when grown on high-Se soils. They are termed non-accumulators (Bell, Parker, & Page, 1992). Certain plant species are known to accumulate Se at levels far be- yond those observed in other species, even from low Se soils. Their Se levels can reach 1000–5000 mg kg 1 dry weight or 0.1–5.0% of plant dry weight without any signs of toxicity (Brown & Shrift, 1982; Feist & Parker, 2001). They are generally found in soils de- rived from Se-rich Cretaceous shale where Se concentrations can be >10 mg kg 1 .(Beath, Gilbert, & Eppson, 1939; Reeves & Baker, 2000). These accumulating plants can be divided into two groups: primary accumulators (hyperaccumulators) and secondary accumulators (indicator species). Hyperaccumulation of Se has been observed in plant families Asteraceae, Cruciferae, Chenopodi- aceae, Lecythidaceae, Fabaceae, Rubiaceae and Schrophulariaceae. Se uptake by plants generally follows sulphate absorption mecha- nism, especially in Cruciferae species such as Brassica sp., as there is not distinct differentiation between soluble forms of selenium ions and sulphate ions (Banuelos, Mead, & Hoffman, 1993). Selenium has been shown to be essential for life and to be toxic at levels slightly above those required for health. Indeed, dietary levels of the desired amount of Se are in a very narrow range; con- sumption of food containing less than 0.1 mg kg 1 of this element will result in its deficiency, whereas dietary levels above 1 mg kg 1 will lead to toxic manifestations (Wada, Kurihara, & Yamazaki, 1993). Although selenium is toxic in large doses, it is an essential micronutrient for health. Most of the in vitro and animal studies carried out in the last 35 years demonstrate that application or in- takes of Se at supra-nutritional levels can inhibit tumorigenesis (Björkhem-Bergman et al., 2005; Ip, 1998). Seeds of Brassica juncea (Indian mustard) are a good source of essential nutrients. According to the USDA National Nutrient Data- base, 100 g mustard seed contain approximately 28 g carbohy- drate, 26 g protein, 36 g total fat, 12 g dietary fibre and 0% cholesterol. They also contain trace amount of all types of vitamins, electrolytes (Na and K) and essential minerals, like Ca, Cu, Fe, Mg, Mn, Se and Zn. Due to its high nutritional value, mustard cake (de-oiled mustard meal) is prominently used as a supplement for 0308-8146/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2012.02.140 ⇑ Corresponding author. Tel.: +91 175 2393318; fax: +91 175 2364498. E-mail address: ntejoprakash@thapar.edu (N. Tejo Prakash). Food Chemistry 134 (2012) 401–404 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem