Moringa leaves rank first among the most widely consumed leafy vegetables in Niger. Glucosinolate contents in leaves of five accessions of three Moringa species (M. oleifera, M. stenopetala and M. peregrina) ranged from 2.65 μmol/g in old leaves of M. stenopetala (Ethiopian-1) to 28.62 μmol/g in

young leaves of M. oleifera (ICG-42). An Indian introduction, PKM-1 (M. oleifera) gave maximum leaf yield

(7.5 t/ha) and had maximum consumer preference than the local (M. oleifera) and Ethiopian-1 (M. stenopetala) genotypes. Large scale dissemination of PKM-1 and use of other species under different production systems are described

Bellostas, N

Christian Sørensen, J

Kumar, S

Nikiema, A

Pasternak, D

Sørensen, H

ICRISAT Open Access Repository

 African Journal of Agricultural Research Vol. 5(11), pp. 1338-1340, 4 June, 2010 Available online at http://www.academicjournals.org/AJAR ISSN 1991-637X © 2010 Academic Journals    Short Communication  Glucosinolates in leaves of Moringa species grown and disseminated in Niger  Natalia Bellostas1, Jens Christian Sørensen1, Albert Nikiema2, Hilmer Sørensen1, Dov Pasternak2 and Sanjeet Kumar3*  1Department of Natural Sciences, Faculty of Life Sciences, University of Copenhagen, Denmark. 2International Crops Research Institute for the Semi Arid Tropics (ICRISAT), Niamey, Niger. 3AVRDC-The World Vegetable Center/ICRISAT Project, Niamey, Niger.  Accepted 22 April, 2010  Moringa leaves rank first among the most widely consumed leafy vegetables in Niger. Glucosinolate contents in leaves of five accessions of three Moringa species (M. oleifera, M. stenopetala and M. peregrina) ranged from 2.65 µmol/g in old leaves of M. stenopetala (Ethiopian-1) to 28.62 µmol/g in young leaves of M. oleifera (ICG-42). An Indian introduction, PKM-1 (M. oleifera) gave maximum leaf yield (7.5 t/ha) and had maximum consumer preference than the local (M. oleifera) and Ethiopian-1 (M. stenopetala) genotypes. Large scale dissemination of PKM-1 and use of other species under different production systems are described.  Key words: Glucosinolate, Moringa spp., Niger   INTRODUCTION   Moringa (Moringa spp.) is a softwood perennial tree that belongs to the monogeneric family Moringaceae (order Capparales). Among the 13 species of the genus Moringa (Ray et al., 2006), M. oleifera (synonyms: horseradish tree, drumstick tree, benzolive tree, kelor, marango, mlonge, moonga, mulangay, nébéday, saijhan, sajna or ben oil tree) and M. stenopetala (Ethiopian moringa) are most commonly cultivated in South India, Ethiopia, Philippines, Sudan and other tropical countries (Fahey, 2005). M. oleifera is a native of the sub-Himalayan tract of the Indian subcontinent, whereas M. stenopetala and M. peregrina originated in Ethiopia and the Arabian Peninsula, respectively. In a survey of 120 Asian indigenous vegetables for nutrient content, antioxidant activity and traditional knowledge on their medicinal uses, M. oleifera was among the most promising species (Ray et al., 2006). This tree is an outstanding source of nutrients in developing regions of the world where undernourishment is a major concern (Fahey, 2005). In Niger, moringa is among the most preferred and consumed leafy vegetables. Being a multi-purpose  perennial  (Bennett  et  al., 2003),  moringa  has    *Corresponding author. E-mail: sanjeet.kumar@worldveg.org, s.kumar.avrdc@cgiar.org. Fax: 227-20734329. considerable potential to contribute to food security under predicted adverse effects of climate change on agriculture. Glucosinolates are a family of natural products present in species of the order Capparales (Bellostas et al., 2007a). These phytochemicals are precursors of a wide range of bioactive compounds with demonstrated antibiotic, anticancer and antioxidant properties (Fahey, 2005). Glucosinolate profile and concentration are species- and genotype-dependent; even different tissues of a single plant show variations (Bellostas et al., 2007b). Concentration also is influenced by growing conditions and the plant’s growth stage (Bellostas et al., 2007b). The glucosinolate content of young and old leaves of moringa species grown in Niger were analyzed. The results are discussed in the light of our efforts to promote moringa under different production systems.    MATERIALS AND METHODS  Five accessions of three Moringa species were used (Figure 1). Young and old leaves were collected from three trees (2 - 3 years old) of each species in September, one of the months when moringa leaves are typically consumed. Four of these lines are being maintained at the AVRDC/ICRISAT vegetable breeding project at ICRISAT farm at Sadore, Niger and a local line was grown   near   Niamey,   Niger. Leaves were pooled and air-dried at  Bellostas et al.       1339    0 5 101520253035ICG-42 PKM-1 Local M. oleifera M. Stenopetala M. Peregrina  Young leaves Old leaves Average   Figure 1. Glucosinolates (µmol/g) in leaves of moringa species.    room temperature (25ºC) prior to shipping to the laboratory in Copenhagen, Denmark. It should be freeze-dried and ground samples (0.8 g) were extracted in duplicate at 100ºC in a Pressurized Solvent Extraction (PSE) using 100% methanol as solvent and with a preheating step (Petersen et al., 2007). The extracts were then dried, re-dissolved in 5 mL milli Q water and glucosinolate concentration was estimated along with two internal standards. Desulphoglucosinolates were determined by Micellar Electrokinetic Capillary Chromatography.    RESULTS AND DISCUSSION  Glucosinolate content   The glucosinolate content in young and old leaves of five accessions varied from 2.65 µmol/g in old leaves of M. stenopetala (Ethiopian-1) to 28.62 µmol/g in young leaves of M. oleifera (ICG-42). All three M. oleifera accessions had higher glucosinolate concentration than the two other moringa species (Figure 1). Glucosinolate content is species and cultivar- specific (Bellostas et al., 2007b). Young leaves of all species consistently showed higher glucosinolate concentration than old leaves, in keeping with results shown for other glucosinolate-containing species (Bellostas et al., 2007b) as well as for moringa (Bennett et al., 2003). Despite showing similar patterns, the glucosinolate values obtained in this study are lower than those reported by Bennett et al. (2003). This difference can likely be attributed to the different genotypes used in the studies, differences in growth conditions, as the extraction procedure although new, has been proven accurate (Petersen et al., 2007). As previously described (Bennett et al., 2003), 4-(-L-rhamnopyranosyloxy)-benzylglucosinolate was found to be the quantitatively dominating glucosinolate present in all the species examined. In addition to 4-(-L-rhamnopyranosyloxy)-benzylglucosinolate, three different acetyl  derivatives  of  the  same glucosinolate  were  also found in the Moringa species examined. Glucosinolates are a complex group of compounds (Bellostas et al., 2007a) and depending on their actual structure and concentration in the diets, the biochemical – physiological effects can be either positive or negative (Andersson et al., 2008). Hence, there is a need for generating additional information on the potential impact on health of the moringa glucosinolates. The average glucosinolates content in seeds of M. oleifera variety PKM-1 (43.14 µmol/g) was significantly higher than that in the young (13.16 µmol/g) and old leaves (7.12 µmol/g), as also shown earlier (Bennett et al., 2003). Reproductive organs tend to accumulate larger amounts of glucosinolates than vegetative tissues (Bellostas et al., 2007b). Hence, in a food-based approach to fight hidden hunger (Ray et al., 2006), moringa pod consumption should also be encouraged in country like Niger where moringa leaves are frequently consumed.   Antioxidants   Significant variation in antioxidant activity (AOA) has been reported in four Moringa species, with M. peregrina showing maximum AOA (Ray et al., 2006). In this study, leaves of all three species surveyed had a high content of similar flavonoid glycosides (data not given) and it is likely that these compounds represent an important part of the AOA in moringa leaves as also shown by Ray et al. (2006).   Promotional efforts   Among all genotypes, PKM-1 variety of M. oleifera gave maximum yield of about 7.5 t/ha of leaves under on-station   irrigated   trials.  PKM-1   was  developed in India     1340     Afr. J. Agric. Res.    Table 1. Consumer preference of leaves of three moringa genotypes.  Consumer type (# of tasters) Taste ranking M. oleifera M. stenopetala Local PKM-1 Ethiopian-1 Nigerian-Rural (25) 3.12 4.72 1.80 Nigerian-Urban (19) 2.85 4.45 2.35 Non-Nigerian (8)* 2.38 4.62 2.50 Mean ± SE 2.78 ± 0.175 4.60 ± 0.098 2.22 ± 0.144  Note: Each participant tasted leaves (boiled in water and salt for one hour) of three genotypes (labeled A, B, C) and ranked them on a 1-to-5 scale; *First time tasted moringa leaves.    primarily for pods, but prior to its dissemination consumer preference for leaves of PKM-1, a local line of M. oleifera and M. stenopetala was studied. An organoleptic taste trial with cooked leaves revealed that PKM-1 leaves were most preferred by both urban and rural consumers in Niger (Table 1). This meant that moringa growers could realize better returns from cultivating PKM-1 for pods and leaves and opened the door for large scale dissemination of it in Niger. PKM-1 is being promoted under different irrigated cropping systems including African Market Garden (AMG), a low pressure drip irrigation system predominantly based on vegetable cultivation, promoted in the Sudano-Sahel region of West Africa (Pasternak et al., 2006).  Moringa is promoted in a range of developmental schemes operating in Niger. The most recent effort is through moringa values chain development, a project implemented by Co-operative League of USA (CLUSA), which involves on-station and on-farm trainings in moringa leaf and seed production for trainers and growers. In the past couple of years, approximately 135 hectares (based on on-station seeds produced and disseminated) of PKM-1 have been planted in Niger. Cultivation of Ethiopian moringa (M. stenopetala) along with xerophytic high value trees and indigenous vegetables such as okra (Abelmoschus esculentus) are being disseminated under rain-fed conservation agriculture systems on degraded lands, a system that we call Bio-Reclamation of Degraded Land (Pasternak et al., 2009). The desert moringa (M. peregrina) currently is being evaluated for its suitability as a root stock for PKM-1 to enable its cultivation under rain-fed/dryland agriculture. It would be worthwhile to appraise the impact and contribution of these dissemination efforts toward nutritional security and livelihood.            REFERENCES   Andersson C, Brimer L, Cottrill B, Fink-Gremmels J, Jaroszewski J, Sørensen H (2008). Glucosinolates as undesirable substances in animal feed: scientific opinion of the panel on contaminants in the food chain. The EFSA J.l 590: 1-76. Bellostas N, Sørensen AD, Sørensen JC, Sørensen H (2007a). Genetic variation and metabolism of glucosinolates. Adv. Bot. Res. 45: 369-415.  Bellostas N, Sørensen JC, Sørensen H (2007b). Profiling glucosinolates in vegetative and reproductive tissues of four Brassica species of the U-triangle for their biofumigation potential. J. Sci. Food Agric. 87: 1586-1594.  Bennett RN, Mellon FA, Foidl N, Pratt JH, Susan DM, Perkins L, Kroon PA (2003). Profiling glucosinolates and phenolics in vegetative and reproductive tissues of the multi-purpose trees Moringa oleifera L. (Horseradish Tree) and Moringa stenopetala L. J. Agric. Food Chem. 51: 3546-3553. Fahey JW (2005). Moringa oleifera: A review of the medical evidence for its nutritional, Therapeutic, and prophylactic properties. Part 1. Trees for Life J. www.TFLJournal.org. Pasternak D, Nikiema A, Senbeto D, Dougbedji F, Woltering L (2006). Intensification and improvement of market gardening in the Sudano-Sahel region of Africa. Chronica Hortic. 46: 24-28.  Pasternak D, Senbeto D, Nikiema A, Kumar S, Fatondji D, Woltering L, Ratnadass A, Ndjeunga J (2009). Bioreclamation of degraded African lands with women empowerment. Chronica Hortic. 49: 24-27. Petersen IL, Hansen HCB, Ravn HW, Sørensen JC, Sørensen H (2007). Metabolic effects in rapeseed (Brassica napus L.) seedlings after root exposure to glyphosate. Pestic. Biochem. Phys. 89: 220-229. Ray RY, Tsou SCS, Lee TC, Chang LC, Kuo G, Lai PY (2006). Moringa, a novel plant rich in antioxidants, bioavailable iron and nutrients. In Wang M (ed), Herbs: Challenges in Chemistry and Biology of Herbs, Am. Chem. Soc. US pp. 224-239.         

Glucosinolates in leaves of Moringa species grown and disseminated in Niger

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