British Biotechnology Journal 6(2): 43-50, 2015, Article no.BBJ.2015.026 ISSN: 2231–2927 SCIENCEDOMAIN international www.sciencedomain.org Compositional and Amino Acid Profile of Nicker Bean (Entada gigas) Seeds H. N. Ogungbenle1* and O. T. Oyadipe1 1Department of Chemistry, Ekiti State University, P.M.B. 5363, Ado - Ekiti, Nigeria. Authors’ contributions This work was carried out in collaboration between both authors. Author HNO designed the study, performed the statistical analysis, wrote the protocol, managed the literature searches and wrote the first draft of the manuscript. Author OTO managed the analyses of the study. Both authors read and approved the final manuscript. Article Information DOI: 10.9734/BBJ/2015/14681 Editor(s): (1) Alok Adholeya, Biotechnology and Management of Bio-resources Division, The Energy and Resources Institute, India. (2) Kuo-Kau Lee, Department of Aquaculture, National Taiwan Ocean University, Taiwan. Reviewers: (1) Fagbemi, Tayo Nathaniel, Food Science and Technology, Federal University of Technology, Nigeria. (2) Anonymous, USA. (3) Anonymous, Nigeria. (4) Anonymous, Mexico. (5) Anonymous, Brazil. Complete Peer review History: http://www.sciencedomain.org/review-history.php?iid=806&id=11&aid=7900 Received 14th October 2014 th Original Research Article Accepted 6 December 2014 th Published 27 January 2015 ABSTRACT The proximate, anti-nutritional factors, functional properties, minerals and amino acid composition of nicker bean (Entada gigas) were determined. The sample contained crude protein and carbohydrate of 24.8±0.02% and 47.2±0.10% respectively. The sample exhibited good emulsion capacity and emulsion stability of 62.3±0.03% and 36.2±0.01% respectively. The foaming capacity was 35.0±0.02% while the least gelation concentration was 4.00±0.01%. It contained nutritionally valuable minerals. The values of the anti-nutritional factors were: phytate (6.59±0.50 mg/g), oxalate (3.50±0.10 mg/g) and tannin (0.26±0.02%). Glutamic acid was the most abundant amino acid with the value of 51.1 g/100 g crude protein while methionine (4.10 g/100 g crude protein) was the least abundant amino acid in the sample. Entada gigas is a potential source of nutrients that should be cultivated and its consumption encouraged. Keywords: Proximate; anti-nutritional; functional; minerals; amino acid. _____________________________________________________________________________________________________ *Corresponding author: E-mail: [email protected]; Ogungbenle and Oyadipe; BBJ, 6(2): 43-50, 2015; Article no.BBJ.2015.026 1. INTRODUCTION 200 ml of 1.25% H2SO4 in 500 ml conical flask and boiled for 30 minutes. The mixture was later Global alliance for improved nutrition is filtered through muslin cloth, rinsed with hot paramount to food scientists. Food scientists are distilled water and scrapped back into the flask always in search for newly improved and and added 200 ml of 1.25% NaOH and allowed underutilized legumes in order to proffer to boil again for another 30 minutes. The mixture solutions to the global food shortages and was filtered, rinsed with 10% HCl twice with consequent malnutrition which has lead to series industrial methylated spirit and allowed to drain of prevalent diseases. Entada gigas has not and dry. The residue was scrapped into a been consumed as food in Africa but as crucible, later dried in an oven at 105ºC, cooled medicinal plant for local treatment of some in a desicator, re-weighed and finally incinerated ailments. It is known as fever nut; spreading in muffle furnace at 300ºC for 30 minutes, again vine-like in nature which grows as tall as 6-7 m in cooled at room temperature and re-weighed [4]. length and uses other vegetation for support. The The carbohydrate value was calculated by stem is covered by sharp spines which may grow difference. to 0.4 or more metres in diameter [1] and the seed grows in a flat pod with length of 0.04 m. 2.2 Determination of Functional Properties Two or three hard smooth seeds of 0.01 m in length are contained in each pod. The seeds The water and oil absorption capacities of the inside pod are olive green in colour and later sample were determined using the methods of become dark-red brown at maturity. Entada Beuchat [5]. Ten milliliters was added to 1.0 g gigas is very common in coastal habitats sample in a centrifuge tube. The suspension was including beaches and dry areas in West Africa mixed vigorously using Marlex mixer and then [1]. The data obtained from the analyses would centrifuged at 15,000 rpm for 15 minutes and the help us to know whether the sample has good volume of the supernatant was recorded. The nutritional values as other existing edible plants bound water was calculated from the difference or may be processed for future consumption in the initial volume of the solvent used and the because the seed is known in Africa to contain final volume after centrifuging. The same certain toxins which hinder its edibility. Functional procedure was used for oil absorption capacity properties of any food must be known before it by replacing King’s vegetable oil of density 0.880 can be incorporated into food system such as g/ml with water in the method described above. emulsification, foamability and gelation [2]. Therefore, the aim of this work is to determine The emulsion capacity and stability were the proximate, functional properties, anti- determined according to methods of described nutrients and amino acid composition of the by Lin et al. [6]. Two grams sample flour was sample. added to 100 ml distilled water and blended for 30 seconds using Marlex food mixer at a high 2. MATERIALS AND METHODS speed. After complete dispersion, 5 ml portion of King’s vegetable oil of 0.880 g/ml density was The sample used for the present work was added from a burette with continuous blending bought in Ado-Ekiti central market, Ekiti State until the emulsion break point (i.e. a separation Nigeria in Africa continent. The 5 kg of the into two layers) at room temperature. The value sample was separated from the shells, later obtained was expressed as gram of oil emulsified dried and ground into flour. The flour was per 1 gram of the sample. packaged and stored in freezer (-4°C) prior to the analyses. The emulsion stability was determined as the volume of the water separated after 24 hours at 2.1 Proximate Analysis room temperature. The slightly modified method of Sathe et al. [7] The moisture and total ash contents were was used to determine the least gelation determined using the air oven and muffle furnace concentration. Sample slurries of 2, 4, 6, 8, 10, as described by Pearson [3]. The sample was 12, 14, 16, 18 and 20% were prepared in 5 ml analyzed for crude fat and crude protein using portions of distilled water. The test tubes methods of AOAC [4] and the percentage containing these slurries were heated for one nitrogen was converted to crude protein by hour in boiling water followed by rapid cooling for multiplying by 6.25. The crude fiber was 2 hours at -4ºC. The least gelation concentration determined by adding 2 g of the sample into 44 Ogungbenle and Oyadipe; BBJ, 6(2): 43-50, 2015; Article no.BBJ.2015.026 was determined as concentration which did not 2.5 Determination of Amino Acid slip when the test tubes were inverted. The amino acid profile was determined using the The method of Coffman and Garcia [8] was method described [13]. The sample was dried to employed to determine foaming capacity and constant weight and defatted using Soxhlet stability. One gram of the sample was whipped extractor. After the defatting process, the with 50 ml distilled water for 5 minutes in a defatted sample (2 g) was weighed into a glass Marlex food mixer and later poured into a 100 ml ampoule; 7 ml of 6MHCl was added and oxygen graduated flask to study the foaming capacity was expelled by passing nitrogen into the (per cent increase in volume). The foaming ampoule so as to avoid possible oxidation of stability was determined as the difference some amino acids during hydrolysis. The glass between the foam and the water level after 2 hrs. ampoule was then sealed with bunsen burner flame and placed in an oven at 105±5ºC for 22 2.3 Mineral Analysis hours. The ampoule was allowed to cool before broken at the tip and the content was filtered to remove the organic matters. The filtrate was then The minerals were analyzed by dry ashing the evaporated to dryness at 40ºC under vacuum in sample at 550ºC in a Carbolite, Sheffield muffle a rotavapor (BÜCHI Rotavapor, R110). The furnace to constant weight and dissolving the ash residue was dissolved in 5 ml of acetate buffer in 100 ml standard flask using distilled deionized (pH 2.0) and stored in specimen bottles which water with 3 ml of 3 M HCl. Sodium and were kept in the freezer. The hydrolysate (7.5 potassium were determined using a flame µL) was dispensed into the cartridge of the photometer (model 405, corning, U.K). All other Technicon Sequential Multi-Analyser (TSM) minerals were determined using Atomic using a syringe. The TSM analyser is designed Absorption Spectrophotometer (Perkin & Elmer to separate and analyse neutral, acidic and basic model 403, USA) [9]. amino acids of the hydrolysate. The amount of amino acid was obtained from the chromatogram 2.4 Determination of Anti Nutrients peaks. The whole analysis lasted for 76 minutes and the gas flow rate was 0.50 ml/min at 60ºC with reproducibility consistent within ±3%.