Food Security

S. Kumar, M. K. Satapathy and P. K. Jena. (2011). Quantitative estimation of total free amino acid among Amaranthus species: Implication for dietary protein. Plant Science Research.  33 (1&2): 127-129.

Quantitative estimation of total free amino acid among Amaranthus species: Implications for Dietary Protein

                            Sanjeet kumar¹, M.K.Satapathy^2ψ and P.K.Jena¹

¹Department of Botany, Ravenshaw University, Cuttack

²Department of Life Science, Regional Institute of Education, Bhubaneswar

Abstract

Total free amino content in five selected Amaranthus species viz. A.caudatus , A.cruentus, A.spinosus, A.tricolor and  A.viridis were evaluated. A.cruentus had the highest amino acid content amounting 0.0231mg per 1 gm fresh leaf. Compared to wild amaranthus, cultivated species possessed higher amino acid content. The work bears relevance in the context of alleviating malnutrition among the tribal and rural populace of Odisha

Key Words: Amaranthus species, Free Amino acid, Amino acid and protein

                      malnutrition

Introduction

Odisha is one of the poor states of the country with about 47 % of the population living below poverty line. The shortage of animal protein and amino acid sources particularly among rural and tribal people of the state has necessitated the search for alternative source of amino acid for possible incorporation into human diet in place of expensive source such as meat, fish, soybean etc (Oke, 1973). Since agriculture came into practice, only about 20 different crop plants have been utilized as the major food source till date. It is estimated that the potential of nearly 1000 wild plant species having food value remains to be exploited. As such, it is not only necessary to use the available rich diversity and wild genetic base to improve the existing conventional cultivars but it is equally important for using those as non-conventional and lesser known food crops (Brenner et al., 2000). The leafy vegetables are the cheapest and the most widely available source of protein, minerals, vitamins etc. However, many of those local green leafy vegetables are underexploited because of inadequate scientific knowledge of their nutritional potential. Amaranthus, an annual erect branched weed, mostly grows in cultivated fields including home gardens, degraded lands, built up areas, along river, road side and forest edges. The leaves of Amaranthus species of both wild and cultivated type are often used as green leafy vegetables. Keeping this in view an attempt has been made in the present study to find out the nutritional value of Amaranthus leaves in terms of total free amino acid content.

Plant Material

Amaranthus is widely distributed among the temperate and tropical regions of the world. The origin of various species of cultivated Amaranthus is not easy to trace because the wild ancestors are pantropical cosmopolitan weeds (Joshi and Rana, 1991).  Amaranthus is an annual herb with three sub-species and 70 species distributed throughout the world. In Odisha, Amaranthus is represented by 06 species ( Saxena and Brahmam, 1995) viz; A.spinosus, A.tricolor, A.graecizans, A.viridis, A.caudatas and A.hybridus. The genetic characters describe the plants as annual herbs with alternate leaves, unisexual flowers in cluster, which may be axillary or erect or drooping, sometimes panicled spikes. Inflorscence is basically cymose, bracteates consisting entirely of dense to lax axillary cluster or the upper cluster leafless and more or less approximate to form a lax or dense spike or panicles. Flowers monocious or dioecious with bracteoles. Perianth free or connate at base, membranous, those of the female flowers sometimes slightly accrescent in fruit. Stamens free usually equal in number to the perianth segment. Carpel 2, ovule solitary, erect. Utricle indehiscent, irregularly rupturing or commonly circumscible seeds usually black and shinning.

Materials and Methods

The plant materials were collected from the forest area of Regional Plant Resource Centre (RPRC), Chandaka forest area, Botanical garden and   different Haat (local weekly market) of Bhubaneswar. All biochemical investigations were done with support from the Plant Biotechnology Division of RPRC following standard methods. Extraction was done using N-perchloric acid and the free amino acid estimation was done using citrate buffer, glycine and Ninhydrin reagent following Ninhydrin reaction method (Moore and Stein, 1998).

Results and Discussion

The percentage of moisture content and dry matter of Amaranthus species have been given in Table- 1. A. cuentus had the highest moisture content followed by A.tricolor. A.spinosus had the lowest level of moisture. The total free amino acid per gram of fresh leaf extract of Amaranthus species has been shown Figure 1. The leaves of the cultivated species showed appreciable amount of amino acid whereas the wild species had less amount. Green leafy vegetables constitute an indispensable component of human diet in developing countries including India. It is presumed that more than 50 species of green leafy vegetables are alone consumed by rural and tribal people of Odisha. However, the food qualities of these plant species are underexploited because of inadequate scientific knowledge of the nutritional values. In the present study, the leaves of A.caudatus and A.cruentus were found to have high amount of amino acid content and possibly can contribute to the nutritional requirement of common man in terms of amino acid / protein supplement in the diet. The leaves of other Amaranthus species having high level of moisture and limited amino acid content can also be useful for human diet. A.cruentus is better than many wild species and thus  can be used to reduce malnutrition and also for defending the deadly diseases like homocystinuria, phenylketonuria(PKU), maple syrup urine disease( MSUD), tyrosinaemia, cystinuria etc (Obradovic et al., 2003).

Table 1:  Mean Percentage and Standard Deviation of moisture and dry matter in the leaves of Amaranthus species.

Name of plant species	Mean Moisture % ± Standard Deviation	Mean Solid % ± Standard Deviation
Amaranthus cruentus L.	87.73 ± 0.022	12.26 ± 0.10
Amaranthus caudatus L.	83.57 ± 0.46	16.42 ± 1.04
Amaranthus tricolor L.	81.10 ±  0.18	18.89 ± 0.45
Amaranthus viridis L.	80.29 ± 0.16	19.70 ± 0.25
Amaranthus spinosus L	75.89 ± 0.28	24. 10 ± 0.55

Analysis of total free amino acid should not be the sole criterion for assessing the nutritional value of this plant and it needs to have a detail study to determine the overall nutritional value intense of proteins, carbohydrate, vitamins, lipids etc. It has been reported (Leung, 1968) that Amaranthus species are good source of protein, vitamin and minerals and especially of lycine. Amaranthus species are considered as promising  non-conventional protein in a modern diet. Further, the high level of lycine highlights the importance of Amaranthus species as a herbal cure for Hepatic infections (Stintzing et al., 2004). Besides the nutritional value of the plant, it also acts as suitable species in the process of crop rotation in sustainable agriculture.

Acknowledgements

The authors gratefully acknowledge the support received from Dr. R.C.Misra, Ms. Suchismita Swain and Director, Regional Plant Resource Centre, Bhubaneswar for carrying out the present study.

References

Brenner, D.M., Baltensperger, D.D., Kulakow, P.A., Lehmann, J.W., Myers, R.L., Slabbert, M.M. and Sleugh, B.B.( 2000). Genetic resources and breeding of Amaranthus. Plant Breeding Reviews. 19: 227-285.

Joshi, B.D. and Rana, R.S. (1991). Grain Amaranths: the Future Food Crop. National Bureau of Plant Genetic Resources, New Delhi. pp.152.

Leung, W.T.W., Busson, F. and Jardin, C. (1968). Food composition table for use in Africa. FAO, Rome, Italy. pp. 306.

Moore, S. and Stein, W.H. (1954). A modified ninhydrin reagent for the photometric determination of amino acids and related compounds. J Biol Chem. 211(2):907–913.

Oke, O.L. (1973). Leaf protein research in Nigeria: a review .Trop Sci 15:139-155.

Saxena, H.O. and Brahmam, M. (1995).. The Flora of Orissa: Acanthaceae to Commelinaceae. Regional Research Laboratory, Bhubaneswar .3:1507-1512.

Stintzing, CF., Kammerer D., Schieber A., Adama H., Nacoulma G.O. and Carle R. ( 2004). Betacyanins and phenolic compounds from Amaranthus spinosus L. and Boerhavia erecta L..Z. naturforsch. 59(C) : 1-8.

Obradovic, Z., Peng K., Vucetic S., Radivojac P., Brown C.J. and Dunker A.K.( 2003). Predicting intrinsic disorder from amino acid sequence. Proteins: Structure, Function and Genetics. 53: 566-572.