Selenium Species Determination in Selenium-Enriched Pumpkin (Cucurbita pepo L.) Seeds by HPLC-UV-HG-AFS

Abstract

In the last decade, many studies have been conducted to enhance the selenium content of edible plants by different types of cultivation. Although it is not known if Se exerts any beneficial effects on the plants themselves, Se enrichment of plants improves the nutritional status of selenium in man. Recently, some studies have shown that appropriate selenium addition to plants promotes their growth and is also supposed to increase their antioxidative capacity, helping to decrease oxidative stress in plants. 1,2 The reactivity and nutritional bioavailability of selenium in selenium-enriched plants depend not only on the total concentration, but predominantly on the selenium species present. Consequently, it is very important to determine the chemical species of selenium present in plants. 3 Selenium-enriched plants accumulate selenium in different forms: cereals and yeast predominantly as SeMet, and Allium plants as Se-methylselenocysteine (SeMeSeCys). [4][5][6] Bodo et al. determined the selenium species in Brazil nuts and, because of the high fat content of the samples, they defatted them first by extraction with cyclohexane; only 0.2% of selenium was lost in this procedure. 7 The main selenium species in these nuts was SeMet, representing 96% of the total Se content; traces of selenocystine (SeCys2) were also found. Another study on selenium speciation in some nuts (Brazil nuts, walnuts…) was made by Kannamkumarath et al. and much lower contents for Se in the form of SeMet were obtained (19 -25%). They used chloroform and methanol (2:1) to remove fat.8 All nuts were purchased on the market, so no data on the origin of samples were given.A renewed nutritional interest in pumpkins has arisen because of its high nutritional value; the pumpkin contains many nutritional sterols, vitamins B and E, and minerals such as Ca, K, P, Mg, Mn, Fe and Zn. Pumpkin seeds have been used for centuries in traditional medicine, mainly in the case of problems of the kidney or the urinary tract, and against tapeworms. They are normally only a moderate source of selenium. But lately several studies were made to enhance the selenium content in edible plants by different types of cultivation. In our previous work, we already studied the ability of pumpkin seeds to accumulate selenium by foliar application of an aqueous solution containing 1 mg Se/L and we found that the Se content of Se treated plants was about 3.5-fold higher than in nontreated ones. So it was concluded that pumpkin seeds are an appropriate food item for selenium enrichment. 9 For determination of water soluble species of selenium in biological samples, the most often used techniques are ion exchange (cation and anion) and reverse phase liquid chromatography with different detection systems (ICP-MS, AAS, AFS, ETAAS). 10 In the literature, HPLC is most often used in connection with ICP-MS, 4,11-15 HG-AAS 16 and HG-AFS. 7,[17][18][19] For separation of volatile selenium species, GC may be used. 20 The aim of this work was to identify and quantify the selenium species in ...

Selenium species in the roots and shoots of chickpea plants treated with different concentrations of sodium selenite

“…Broccoli accumulates high levels of Se in the form of SeMeSeCys (Lyi et al 2005). Contrasting to numerous research publications reporting about SeMet as the main Se species in buckwheat and pumpkin seeds, wheat, barley and rye (Smrkolj et al 2005(Smrkolj et al , 2006aStadlober et al 2001), rice (Stadlober et al 2001;Hart et al 2011;Whanger 2002;Zhang et al 2012), lentil grains (Thavarajah et al 2008), or chickpea sprouts (Zhang et al 2012), SeMet could not be detected in significant high concentrations in the chickpea shoots and roots of semihydroponically grown plants presented here. In soybean and kidney bean sprouts, Se was detected in the form of SeMeSeCys, with only a minor proportion in the form of SeMet and unidentified Se species (Sugihara et al 2004).…”

Production technology and characteristics of Styrian pumpkin seed oil

“…The physiologically interesting trace element Se was detected in Styrian oil pumpkin seeds. However, since it was mainly incorporated in selenomethionin, it is excluded from the oil fraction [20]. In contrast, iodine was poorly retained in the pressing residue and partitioned in the corresponding pumpkin seed oils at concentrations between 2 and 3 mg/kg oil [21].…”

Efectos Del Enriquecimiento Con Selenio en Spad, Calidad De La Fruta Y Parámetros De Crecimiento De Plantas De Fresa en Un Sistema De Cultivo Sin Suelo

“…Sin embargo, la fortificación agronómica de las plantas cultivadas mediante aplicación foliar con Se es aún poco usada (kÁPOLNA et al, 2009). A pesar de ello, la pulverización foliar de Se(IV) o Se(VI) para aumentar el contenido de Se se ha realizado con éxito en muchos cultivos, como la patata (POGGI et al, 2000), arroz (HU et al, 2002), soja (YANG et al, 2003, col, cebolla, ajo y rábano (SLEJKOVEC y GOESSLER, 2005), trigo y calabaza (SMRKOLJ et al, 2005;SMRKOLJ et al, 2006). No obstante, en el caso de la fresa (Fragaria x ananassa Duch.…”