Antioxidant-rich amaranth varieties, Arka Samraksha and Arka Varna B. Varalakshmi, V. Kesava Rao1 and G. Naik2 Division of Vegetable Crops, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore – 560 089 E-mail : bvl@iihr.ernet.in ABSTRACT Amaranth improvement in India hither to was concerned with development of high-yielding varieties, and hardly any research efforts have been made for its nutritional improvement. Keeping this in view, at Indian Institute of Horticultural Research two high-yielding amaranth varieties, Arka Samraksha and Arka Varna with high antioxidant activity, low amounts of nitrates and oxalates were developed using modified bulk method of selection from segregating population of the crosses IIHR-4 x IIHR-70 and IIHR-7 x IIHR-30 . Arka Samraksha is a high-yielding (10.9 t/ha in 30-35 days), pulling-type variety with green leaves and stem, antioxidant activity of 499mg (AEAC units) and minimum nitrate content of 27.3 mg and 1.34 g oxalates per 100 g fresh leaf weight. Arka Varna also a pulling type, high-yielding variety (10.6 t/ha in 30-35 days) with green leaves and a pink stem, high antioxidant activity of 417 mg (AEAC units), low nitrate content of 37.6 mg and 1.42 g oxalates per 100 g fresh leaf weight. Key words: Amaranth, antioxidant activity, nitrates, oxalate Amaranth (Amaranthus tricolor L.) is one of the important leafy vegetables grown throughout the country. From a nutritional point of view, it enjoys a competitive rank among vegetables, being a very good source of vitamins like Vitamin A (carotene), Vitamin C, folic acid, riboflavin, thiamine and minerals like iron and calcium. These phytochemicals act as powerful antioxidants protecting cells and organs from damage caused by free-radicals and neutralizing their damaging effects. ICMR recommends a daily intake of 400g of vegetables /day/ adult, which comprises 125g of leaf vegetables (Anon., 2009). Regular consumption of these leafy vegetables can substantially improve the health of our population. Nitrates and oxalates present in leafy vegetables in our nutrition for concern. While nitrates may get converted into potential carcinogens like nitrosamines, oxalates can form calcium oxalate (kidney stones). Although levels of oxalates and nitrates present in amaranth do not pose a serious nutritional problem under normal consumption habit, lines that have lower levels of these chemicals are certainly desirable (Ara Der Marerosian et al, 1979). Amaranth improvement in India has been focussed on developing high- yielding varieties, and very limited research work has been done on nutritional improvement (Varalakshmi et al, 1998, 2001).Therefor, at IIHR, research efforts aimed at developing high-yielding amaranth varieties possessing high antioxidant activity with low nitrate and oxalate content resulted in the present amaranth varieties, Arka Samraksha and Arka Varna. Characteristic features and nutritional composition of these two varieties are given in Tables 1 and 2. Arka Varna recorded maximum content of potassium (918mg%), calcium (471.2g%) and magnesium (201.8mg%), whereas Arka Samraksha recorded maximum iron (11mg%) and zinc (0.63g%) content. Salient features of Arka Samraksha’ and Arka Varna’: Arka Samraksha: This variety was developed by modified bulk method of selection from segregating population of the cross IIHR-4 x IIHR-70, in F 6 generation: High-yielding amaranth variety with high antioxidant activity of 499mg (AEAC units) and minimum nitrate content (27.3mg) and 1.34g oxalates per 100g fresh weight of leaves. It is a pulling type amaranth with green leaves and stem; yields 10.9t/ha in 30-35 days. 1 Division of Plant Physiology & Biochemistry, IIHR, Bangalore 2 Principal Scientist (Rtd.), CHES, Bhubaneshwar Short communication J. Hortl. Sci. Vol. 6(2):163-165, 2011 Prinect Color Editor Page is color controlled with Prinect Color Editor 4.0.70 Copyright 2008 Heidelberger Druckmaschinen AG http://www.heidelberg.com You can view actual document colors and color spaces, with the free Color Editor (Viewer), a Plug-In from the Prinect PDF Toolbox. Please request a PDF Toolbox CD from your local Heidelberg office in order to install it on your computer. 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It is a high-yielding amaranth variety, with high antioxidant activity of 417mg (AEAC units), nitrate content of 37.6mg and 1.42g of oxalates per 100g fresh weight of leaves. It is a pulling type amaranth variety with green leaves and pink stem, yields 10.6 t/ha in 30-35 days. Performance of ‘Arka Samraksha’ and ‘Arka Varna’ at IIHR, Bangalore: Arka Samraksha is a green-leaved pulling type amaranth line which was tested for its yield, antioxidant capacity, nitrate and oxalate content for three years (from 2008 to 2010) at IIHR Experimental Farm, Hessaraghatta. Average fresh-greens yield of Arka Samraksha was 10.91t/ha by pulling, 30 -35 days after sowing and, increase over the check variety, Arka Suguna, was 41.8% and over the Local Check 77.4%. It recorded maximum antioxidant activity of 499mg (AEAC units) and minimum nitrate content of 27.3mg, and 1.34g of oxalates per 100g fresh weight of leaves. It also recorded 4.0% leaf protein. Average fresh-greens yield of Arka Varna was 10.58t/ha by pulling in 30-35 days after sowing, and the increase over check variety, Arka Suguna, was 37.6%, and over the Local Check 72.0%. It recorded antioxidant activity of 417mg (AEAC units), nitrate content of 38.2mg and 1.42g of oxalates per 100g fresh weight of leaves. Further, it has recorded 4.1% of leaf protein (Table 3). Performance at different locations: The two varieties were tested at Central Horticultural Experiment Stations of IIHR at Bhubaneswar, and at Hirehalli, for yield and quality during rainy season (June-July) of the year 2009 (Table 4). At Central Horticultural Experiment Station, Bhubaneswar, ‘Arka Samraksha’ recorded fresh-greens yield of 13.9t/ha by pulling, which was superior to the Checks ‘Arka Suguna’ (8.54t/ha) and ‘Local’ variety (8.75t/ha). It recorded antioxidant capacity of 315.2mg (AEAC units) Table 1. Characteristic features of amaranth varieties Arka Samraksha and Arka Varna Trait Arka Arka Arka Local Samraksha Varna Suguna Check Check Leaf color Green Green Green Green Stem color Green Pink Green Green Petiole color Green Pink Green Green Leaf shape Lanceolate Ovate Ovate Ovate Days to 50% flowering 40.0 40.8 40.0 35.0 Plant height (cm) 36.1 38.2 28.4 25.6 Branch number 8.2 8.1 7.3 7.3 Leaf number 57.8 50.0 41.2 44.6 Leaf weight (g) 61.3 59.2 56.7 38.9 Stem weight (g) 89.2 89.8 48.3 55.9 Total plant weight(g) 161.3 154.1 115.1 92.2 Yield in t/ha 10.9 10.6 7.69 6.15 Antioxidant activity 499 417 419.6 389.2 (mg/100g fresh wt.) Nitrate content 27.3 38.2 65.8 82.4 (mg/100g fresh wt.) Oxalate content 1.34 1.42 1.61 1.42 (mg/100g fresh wt.) Table 2. Nutritional composition of amaranth varieties Arka Samraksha and Arka Varna Nutritional component Arka Arka Arka Local Samraksha Varna Suguna Check Check Moisture (%) 86.1 86.5 87.3 86.8 Protein (%) 4.0 4.1 3.4 3.5 P (mg%) 50.9 61.0 44.0 50.9 K (mg%) 715.9 918.0 717.6 627.0 Ca (mg%) 463.6 471.2 357.5 420.4 Mg (mg%) 199.5 201.8 182.9 179.5 S (mg%) 60.4 50.2 42.2 54.1 Fe (mg%) 11.1 6.2 11.5 9.0 Mn (mg%) 0.67 0.71 0.52 0.62 Zn (mg%) 0.63 0.61 0.53 0.59 Cu (mg%) 0.18 0.16 0.14 0.13 Varalakshmi et al J. Hortl. Sci. Vol. 6(2):163-165, 2011 Arka Varna Arka Samraksha Prinect Color Editor Page is color controlled with Prinect Color Editor 4.0.70 Copyright 2008 Heidelberger Druckmaschinen AG http://www.heidelberg.com You can view actual document colors and color spaces, with the free Color Editor (Viewer), a Plug-In from the Prinect PDF Toolbox. Please request a PDF Toolbox CD from your local Heidelberg office in order to install it on your computer. 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Mean performance of amaranth varieties Arka Samraksha and Arka Varna for total yield, antioxidant activity, nitrate and oxalate content during 2008-2010 at IIHR, Bangalore Variety Total plant Yield kg/plot Yield Antioxidant activity Nitrates Oxalates/100g fr. weight (g) (4m2) (t/ha) mg (AEAC units/ (mg/100g fr. leaf wt. ) leaf wt. 100g fresh wt.) Arka Samraksha 161.3 4.36 10.91 499.0 27.3 1.34 Arka Varna 154.1 4.23 10.58 417.0 38.2 1.42 Arka Suguna (c) 115.1 3.08 7.69 419.6 65.8 1.61 Local Check 92.2 2.46 6.15 389.2 82.4 1.42 Mean 133.2 3.55 8.87 428.8 58.2 1.65 C.D. (P=0.01) 47.5 1.27 3.17 39.7 15.6 0.13 CV (%) 8.6 8.05 9.08 15.7 13.6 13.4 Table 4. Performance of amaranth varieties Arka Samraksha and Arka Varna for quantitative / qualitative traits during Kharif 2009 at CHES, Bhubaneswar and Hirehalli CHES, Bhubaneswar CHES, Hirehalli Variety Yield (t/ha) Antioxidant activity Nitrates (mg / Yield Antioxidant activity Nitrates (mg/ 100g Oxalates (100g (mg AEAC units / 100g fr. leaf wt.) (t/ha) (mg AEAC units/ fr. leaf wt.) fr. leaf wt.) 100g fr. leaf wt.) 100g fr. leaf wt. Arka Samraksha 13.87 315.2 29.9 7.56 520.6 34.2 1.2 Arka Varna 9.47 214.0 27.9 6.67 596.4 15.0 1.2 Arka Suguna (c) 8.54 99.2 172.6 4.31 399.1 40.3 1.1 Local check 8.75 183.2 88.2 4.11 433.4 64.9 1.2 Mean 11.69 190.9 73.7 5.5 474.4 67.4 1.2 C.D. (P=0.05) 6.08 36.3 31.7 1.41 42.1 15.6 0.052 CV (%) 13.3 15.3 19.2 6.6 15.3 14.2 7.3 and 29.9mg nitrates per 100g of fresh weight of leaves. At CHES, Hirehalli, by pulling, it recorded 7.56t/ha, which was significantly higher than in the Check, Arka Suguna (4.31t/ ha) and ‘Local’ variety (4.11t/ha). It recorded antioxidant activity of 520.6mg (AEAC units), 34.2mg nitrates and 1.22g of oxalates per 100g fresh weight of leaves. ‘Arka Varna’ at Bhubaneswar recorded fresh-greens yield of 9.47t/ha by pulling, which is superior to the checks ‘Arka Suguna’ (8.54t/ha) and ‘Local variety’ (8.75t/ha). It recorded an antioxidant capacity of 214mg (AEAC units) and 27.9mg nitrates per 100g fresh weight of leaves. At Hirehalli, by pulling it recorded 6.67t/ha, which was significantly higher than in the checks, ‘Arka Suguna’ (4.31t/ ha) and ‘Local variety’ (4.11t/ha). It recorded antioxidant capacity of 596.4mg (AEAC units), 15.0mg nitrates and 1.22g oxalates per 100g fresh weight of leaves at Hirehalli. REFERENCES Anonymous. 2009. Nutrient requirements and recommended dietary allowances for Indians. ICMR Report, NIN, Hyderabad, pp. 320 Ara Der Marderosian, John Beutler, Walter Pfendner, Jefefry Chambers, Robert Yoder, Eileen Weinsteiger and Joseph Senft. 1979. Nitrate and Oxalate content of Vegetable Amaranth. In: Proceedings of the Second Amaranth Conference, RODALE Press, Inc. Emmaus, PA, USA pp. 31-41 Varalakshmi, B., Naik, G., Pratap Reddy,V.V. and Pandey, S.C. 1998. Arka Suguna: new multicut amaranth. Ind. Hort., 42:14-15 Varalakshmi, B., Pratap Reddy, V.V., Naik, G., Celia Chalam V. and Pal, D.K. 2001. ‘Arka Arunima’: a new multicut amaranth. Ind. Hort., 46:29-30 (MS Received 6 May 2011, Revised 6 July 2011) Nutrient-rich new amaranth varieties J. Hortl. Sci. Vol. 6(2):163-165, 2011 Prinect Color Editor Page is color controlled with Prinect Color Editor 4.0.70 Copyright 2008 Heidelberger Druckmaschinen AG http://www.heidelberg.com You can view actual document colors and color spaces, with the free Color Editor (Viewer), a Plug-In from the Prinect PDF Toolbox. Please request a PDF Toolbox CD from your local Heidelberg office in order to install it on your computer. 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