Effect of gamma irradiation on the nutritional and antinutritional qualities of Vigna aconitifolia (Jacq.) Marechal: An underutilized food legume

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

Contents lists available at ScienceDirect

Biocatalysis and Agricultural Biotechnology journal homepage: www.elsevier.com/locate/bab

Effect of gamma irradiation on the nutritional and antinutritional qualities of Vigna aconitifolia (Jacq.) Marechal: An underutilized food legume

MARK

⁎

Pious Soris Tresinaa, Koilpitchai Paulpriyaa, Veerabahu Ramasamy Mohana, , Solomon Jeevab a b

Ethnopharmacology Unit, Research Department of Botany, V.O.Chidambaram College, Tuticorin, Tamil Nadu, India Department of Botany and Research Centre, Scott Christian College (Autonomous), Nagercoil, Tamil Nadu 629003, India

A R T I C L E I N F O

A BS T RAC T

Keywords: Gamma irradiation Vigna aconitifolia Vitamins Amino acids PDCAAS IVPD

Effect of gamma irradiation on the nutritionally potent underutilized wild legume Vigna aconitifolia at various doses (2, 5, 10, 15 and 25 kGy) were assessed for its nutritional and antinutritional factors. Gamma irradiation significantly enhanced the crude protein content at all doses, while crude lipid, crude fibre and ash resulted in a significant dose-dependent decline. Raw seeds are rich in potassium, phosphorus, magnesium, manganese and vitamins (niacin and ascorbic acid); significant diminution was reported in irradiated seeds. The essential amino acids of raw and gamma irradiated seeds were comparable with the FAO/WHO recommended pattern. A significant dose -dependent increase in IVPD on irradiation was observed. High amount of saturated fatty acids decreased after irradiation. However, linoleic acid, palmitoleic acid and eicosenoic acid were increased after irradiation at 25 kGy. Irradiating the seeds with gamma rays significantly curtailed the levels of the toxic nonproteinaceous amino acid, L-DOPA, hydrogen cyanide, trypsin inhibitors, oligosaccharides and phytohaemagglutinins. The aromatic compound, phenols, the water soluble polyphenols and tannins showed a dosedependent significant increase. The overall findings are the indications to improvise the nutritional traits of the gamma irradiated underutilized tribal pulse, V. aconitifolia which could be a good source of protein for human consumption.

1. Introduction Protein energy malnutrition is a widespread problem throughout the world and has both health and economic consequences. It is the most common deficiency disease especially in developing countries (FAO/WHO, 2001). Due to an inadequate supply of proteins of animal origin, nutritionalists, researchers and government organizations worldwide are searching for reliable, cheap and high quality proteins of plant origin. The need to provide inexpensive plant-based protein supplements has led to the examination of underutilized dicotyledonous seeds for human and livestock consumption (Adebowale and Lawal, 2004; Bhat and Sridhar, 2008). Legumes represent an important component of human diet in several areas of the world, especially in the developing countries, where they complement the lack of proteins from cereals, roots and tubers. Among European countries, a higher legume consumption is observed around Mediterranean, with daily consumptions between 8 and 23 g/ capita (DAFNE, 2009). Legumes are low in fat, and rich in proteins, complex hydrocarbons, and minerals (Geil and Anderson, 1994) and exhibit lower glycaemic index compared to other starchy foods. In ⁎

addition, legumes contain a rich variety of phytochemicals, including phytosterols, natural antioxidants and bioactive carbohydrates (Amarowicz and Pegg, 2008; Rochfort and Panozzo, 2007), which if consumed in sufficient quantities may help to reduce tumour risk (Mathers, 2002). Epidemiological and intervention studies indicated that legume consumption is inversely associated with the risk of coronary heart disease (Bazzano et al., 2001), Type II diabetes mellitus (Villegas et al., 2008) and obesity (Rizkalla et al., 2002), and results in lower LDL cholesterol and higher HDL cholesterol (Anderson and Major, 2002; Bazzano et al., 2008). For these reasons, legumes are considered an ideal complement to cereals in vegetarian diets and they gain increasing attention as functional food items. Within the context of the adoption of a healthier diet, it is recommended that legume consumption should increase in the western diet (Leterme, 2002; Bell and Sears, 2003; Kalogeropoulos et al., 2010). Nonetheless, the utilization of these underutilized legumes is limited due to the presence of certain antinutritional compounds. The removal of the undesirable components from the dry legume seed is essential for improving their nutritional qualities and for effectively utilizing them to their full potential as food. To achieve this, several

Corresponding author. E-mail addresses: [email protected] (P.S. Tresina), [email protected] (K. Paulpriya), [email protected] (V.R. Mohan), [email protected] (S. Jeeva). http://dx.doi.org/10.1016/j.bcab.2017.02.002 Received 8 September 2016; Accepted 3 February 2017 Available online 08 February 2017 1878-8181/ © 2017 Elsevier Ltd. All rights reserved.

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

The nitrogen free extract (NFE) was obtained by difference (Muller and Tobin, 1980). The energy value of the seed (kJ) was estimated by multiplying the percentages of crude protein, crude lipid and NFE by the factors 16.7, 37.7 and 16.7, respectively (Siddhuraju et al., 1996).

processing techniques such as germination, soaking and cooking and dry heat treatment have been used (Kakati et al., 2010; Khandelwal et al., 2010; Janardhanan et al., 2003; Bhat et al., 2007; Vadivel and Pugalenthi, 2008). Irradiation treatment as a method of preservation to enhance the shelf-life or to improve the hygienic qualities of raw and processed foods and agricultural commodities has been well established worldwide. Radiation processing has proved to be an effective means of disinfestation and decontamination of food and agricultural products (Anonymous, 1991; Loaharanu, 1994). Radiation treatment itself or in combination with other processing methods has been shown to reduce or eliminate some of the anti-nutrients in cereals and legumes (Farag, 1989; Sattar et al., 1990; Siddhuraju et al., 2002a; Bhat et al., 2008; Tresina and Mohan, 2011) security. A joint FAO/IAEA/WHO study group reviewed the toxicological, nutritional and radiation-induced chemical and physical aspects of irradiated foods above 10 kGy and concluded that application of ionizing radiation at 10 kGy or higher doses will be safe and nutritionally adequate (WHO, 1999). Literatures on the nutritional and antinutritional properties of Vigna aconitifolia seeds are available. Siddhuraju et al. (1994) reported the proximate composition, minerals, seed protein fractions, amino acids, fatty acids and antinutritional factors of Vigna aconitifolia. The total and resistant starch (RS), dietary fibre (DF) and soluble sugars including oligosaccharides of V. aconitifolia were determined by Bravo et al. (1999). Effect of soaking and heat processing on the levels of antinutrients and digestible proteins of V. aconitifolia were reported by Vijayakumari et al. (1998). There are insufficient reports about possible effects of gamma irradiation on nutritional value of V. aconitifolia. Consequently, the present investigation was commenced to explore the impact of gamma irradiation on the nutritional and antinutritional factors of the underutilized legume, V. aconitifolia.

2.4. Minerals and vitamins analyses Five hundred mg of the ground legume seed was digested with a mixture of 10 ml concentrated nitric acid, 4 ml of 60% perchloric acid and 1 ml of concentrated sulphuric acid. After cooling, the digest was diluted with 50 ml of deionised distilled water, filtered with Whatman No. 42 filter paper and the filtrates were made up to 100 ml in a glass volumetric flask with deionised distilled water. All the minerals except phosphorus were analysed from a triple acid-digested sample by an atomic absorption spectrophotometer – ECIL (Electronic Corporation of India Ltd., India) (Issac and Johnson, 1975). The phosphorus content was determined colorimetrically (Dickman and Bray, 1940). Ascorbic acid and niacin contents were extracted and estimated as per the method given by Sadasivam and Manickam (1996). 2.5. Amino acid analyses The total seed protein was extracted by a modified method of Basha et al. (1976). The extracted proteins were purified by precipitation with cold 20% trichloroacetic acid (TCA). A protein sample of 30 mg was hydrolysed by 6N HCL (5 ml) in an evacuated sealed tube, which was kept in an air oven maintained at 110 °C for 24 h. The sealed tube was broken and the acid removed completely by repeated flash evaporation after the addition of de-ionized water. Dilution was effected by means of citrate buffer pH 2.2 to such an extent that the solution contained 0.5 mg protein ml−1. The solution was passed through a millipore filter (0.45 µM) and derivitized with O-phthaldialdehyde by using an automated pre-column (OPA). Aminoacids were analysed by a reverse – phase HPLC (Method L 7400, HITACHI, Japan) fitted with a denali C18 5 µm column (4.6×150 mm). The flow rate was 1 ml/min with fluorescence detector. The cystine content of protein sample was obtained separately by the Liddell and Saville (1959) method. For the determination of tryptophan content of proteins, aliquots containing known amounts of proteins were dispersed into glass ampoules together with 1 ml 5 M NaOH. The ampoules were flame sealed and incubated at 110 °C for 18 h. The tryptophan contents of the alkaline hydrolysates were determined colorimetrically using the method of Spies and Chamber (1949) as modified by Rama Rao et al. (1974). The contents of the different amino acids were expressed as g100g-1 proteins and were compared with FAO/WHO (1991) reference pattern. The essential amino acid score was calculated as follows:

2. Materials and methods 2.1. Collection of seeds The mature seed materials of Vigna aconitifolia (Jacq.) Marechal were collected from Sivagiri Hills, Tamil Nadu. Soon after the collection, the seeds were sun dried for 2–3 days and were surface cleaned with muslin cloth and physically damaged, immature and insect infested seeds were eliminated. 2.2. Irradiation Seed samples (each-50 g) packed in polyethylene pouches were irradiated at different doses of gamma irradiation (2, 5, 10, 15 and 25 kGy) at room temperature (25 ± 1 °C) using a Cobalt -60 Gamma cell 5000 unit at Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakam, Tamil Nadu. Seed samples packed similarly without irradiation served as control. The seed samples were powdered and stored in screw capped bottles for further usage.

grams essential amino acid in 100g of total protein Essential amino acid score = −−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−−X100 grams of essential amino acid in 100g of FAO/WHO (1991) reference pattern

2.3. Analyses of proximate composition The moisture content (%) was determined by drying 50 transversely cut seed in an oven at 80 °C for 24 h and is expressed on a percentage basis. The air-dried samples were powdered separately in a Wiley mill (Scientific Equipment, Delhi, India) to 60-mesh size and stored in screw capped bottles at room temperature for further analysis. The nitrogen content was estimated by the micro-Kjeldahl method (Humphries, 1956) and the crude protein content was calculated (N x 6.25). Crude lipid content was determined using Soxhlet apparatus (AOAC, 2005). The ash content was determined by heating 2 g of the dried sample in a silica dish at 600 °C for 6hr (AOAC, 2005). Total dietary fibre (TDF) was estimated by the non-enzymatic-gravimetric method (Li and Cardozo, 1994).

2.6. Determination of in vitro protein digestibility (IVPD) In vitro protein digestibility (IVPD) of unprocessed and processed seed samples was determined using the multi-enzyme techniques (Hsu et al., 1977). The protein digestibility corrected amino acid score (PDCAAS) of EAA was calculated based on EAA requirements for adults (FAO/ WHO, 1991): 31

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

PDCAAS% = (amino acid content on food protein X true digestibility)

seeds expressed a significant (p < 0.05, p < 0.01) reduction of moisture content than that of the unirradiated V. aconitifolia seeds. Crude protein and carbohydrates are the major chemical constituents of the presently investigated underutilized legume. A non-significant (p > 0.05, p > 0.01) hike was observed in the crude protein content of the irradiated V. aconitifolia seeds. This is in consonance with earlier reports in Mucuna pruriens (Bhat et al., 2007). Similarly gamma irradiation treated pigeon pea flour resulted in a moderate increase in crude protein in all the irradiated doses (control 19.37%; 20 kGy 22.99%) (Bamidele and Akanbi, 2013). After irradiation the soy protein levels were found to be increased slightly in both soy flour and sprouted soy flour; but, significant difference was not observed. The reason for increase in protein levels after irradiation might be due to gamma radiation leading to disruption of the ordered structure of soy protein molecules by degradation, cross linking and aggregating of the peptide chains which decreases the viscosity due to cleavage of polypeptides chains and water vapour permeability by 13%. But mean sensible strength of the soy protein increased two times by γ - irradiation (Jabeen et al., 2015). The crude protein content of the unirradiated seeds was higher than that of the V. unguiculata subsp. cylindrica and V. radiata var. sublobata (Arinathan et al., 2009) and different varieties of Lablab purpureus (Kala et al., 2010); whereas, the crude protein content of the gamma irradiated seeds was higher than that of the gamma irradiated V. unguiculata subsp. unguiculata seeds (Tresina and Mohan, 2011). The crude carbohydrates constitute over 50% of the seed constituents, probably due to low lipids. Irradiation did not significantly (p > 0.05, p > 0.01) affect the carbohydrates and but slightly increased as the irradiation doses increased. Stability of carbohydrates in seeds on irradiation is advantageous as carbohydrates contribute to the calorific value while acting as an anti-marasmus in infant nutrition (Vadivel and Janardhanan, 2000). Gamma irradiation exposed a significant (p < 0.05, p < 0.01) dose-dependent decrement in the crude lipid, crude fibre and ash content of the V. aconitifolia seeds. Low crude fibre is nutritionally valued as it traps less proteins and carbohydrates (Balaogun and Fetuga, 1986). The dose-dependent decrease in fibre on irradiation has been attributed to depolymerization and delignification of the plant matrix (Sandev and Karaivanov, 1977). The calorific values of the currently investigated irradiated seeds were higher when compared to gamma irradiated V. unguiculata subsp. unguiculata seeds (Tresina and Mohan, 2011).

−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Amino acid content of reference pattern

2.7. Lipid extraction and fatty acid analysis The total lipid was extracted from the seeds according to the method of Folch et al. (1957) using chloroform and methanol mixture in ratio of 2: 1 (v/v). Methyl esters were prepared from the total lipids by the method of Metcalfe et al. (1966). Fatty acid analysis was performed by gas chromatography (ASHMACO, Japan; Model No: ABD20A) using an instrument equipped with a flame ionization detector and a glass column (2m×3mm) packed with 1% diethylene glycol succinate on chromosorb W. The temperature conditions for GC were injector 200 °C and detector 210 °C. The temperature of the oven was programmed from 180 °C and the carrier gas was nitrogen at a flow rate of 30 ml/min. Peaks were identified by comparison with authentic standards, quantified by peak area integration and expressed as weight percentage of total methyl esters; the relative weight percentage of each fatty acid was determined from integrated peak areas. The polyunsaturated and saturated fatty acid ratio was calculated as follows:

Polyunsaturated / saturated fatty acid ratio = (sum of saturated fatty acids) = (sum of polyunsaturated fatty acids)

2.8. Analyses of antinutritional compounds The antinutritional compounds, total free phenolics (Bray and Thorne, 1954), tannins (Burns, 1971), the non-protein amino acid, LDOPA (3, 4-dihydroxyphenylalanine) (Brain, 1976), phytic acid (Wheeler and Ferrel, 1971) and hydrogen cyanide (Jackson, 1967) were quantified. Trypsin inhibitor activity was determined by the enzyme assay of Kakade et al. (1974) by using benzoil-DL-arginin-pnitroanilide (BAPNA) as a substrate. One trypsin inhibitor unit (TIU) has been expressed as an increase of 0.01 absorbance units per 10 ml of reaction mixture at 410 nm. One unit of activity corresponds to that amount of trypsin inhibitor in µg protein which gives 50% inhibition of enzyme activity under experimental conditions. Trypsin inhibitor activity has been defined in terms of trypsin units inhibited per mg protein. Extraction of TLC separation and estimation of oligosaccharides were done following the method of Somiari and Balogh (1993) and Tanaka et al. (1975). Lectin activity was determined by the method of Almedia et al. (1991) and Tan et al. (1983).

3.2. Mineral composition and vitamins analyses Raw V. aconitifolia seeds are rich in sodium, potassium, phosphorus, magnesium and manganese (Table 2) when compared with other legumes Dolichos trilobus, Rhynchosia cana, Vigna radiata var. sublobata and V. unguiculata subsp. cylindrica (Arinathan et al., 2009). In the present investigation, V. aconitifolia registered a higher level of potassium when compared with recommended dietary allowance value (RDA) of infants and children ( < 1550 mg) (NRC/NAS, 1980). The high amount of potassium can be utilized beneficially in the diets of people who take diuretics to control hypertension and suffer from excessive excretion of potassium through body fluid (Siddhuraju et al., 2001). Iron, zinc and manganese are antioxidants and they also strengthen the immune system (Talwar et al., 1989). All the minerals presently studied were significantly decreased on irradiation (p < 0.05) at all doses. Irradiation shows signs of a significant (p < 0.05, p < 0.01) dosedependent turn down in the vitamins (niacin and ascorbic acid) content of irradiated V. aconitifolia seeds. The presently examined unirradiated seeds were found to contain higher niacin content than that of Lablab purpureus varieties (Kala et al., 2010), Entada rheedi, Rhynchosia suaveolens and Vigna unguiculata subsp. cylindrica (Arinathan et al., 2009); whereas, the ascorbic acid content was higher than that of Cicer arietinum, Phaseolus aureus, Dolichos biflorus (Khatoon and Prakash, 2006); Phaseolus vulgaris (white and black beans); Cajanus cajan

2.9. Statistical analysis The above said data were estimated on triplicate determinations. Analysis of variance (ANOVA) and Paired samples –‘t’test were used for analysis (SPSS software for windows release 17.0; SPSS/Inc., Chicago IL, USA) of any significant difference in chemical compositions among the gamma irradiated legumes. Significance was accepted at p < 0.05 and p < 0.01. 3. Results and discussion 3.1. Proximate composition The results of the proximate composition and vitamin (niacin and ascorbic acid) contents of the gamma irradiated and unirradiated Vigna aconitifolia seeds are compiled in Table 1. Gamma irradiated 32

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

Table 1 Proximate composition content of Vigna aconitifolia seeds untreated and treated with gamma irradiation (g 100 g−1). Component

Moisture Crude protein Crude lipid Total Dietary Fibre Ash Nitrogen Free Extractives Calorific Values (kJ / 100 g DM)

Dose Raw

2 kGy

5 kGy

10 kGy

15 kGy

25 kGy

4.84 ± 0.11 25.80 ± 0.37 5.10 ± 0.07 5.86 ± 0.12 4.34 ± 0.04 58.90 ± 1.74 1606.76 ± 3.74

4.64 ± 0.09af 26.14 ± 0.14 4.86 ± 0.04af 5.16 ± 0.14af 4.10 ± 0.06af 64.60 ± 1.32 1698.58 ± 3.26

4.14 ± 0.07abfg 27.08 ± 0.15 4.46 ± 0.19abfg 4.34 ± 0.06abfg 3.56 ± 0.05abfg 65.02 ± 1.02 1706.21 ± 2.12

3.98 ± 0.09acfg 27.48 ± 0.36 4.21 ± 0.09abfgh 4.10 ± 0.08 abfgh 3.12 ± 0.03abfgh 65.30 ± 1.54 1708.14 ± 1.74

3.36 ± 0.07abdfgi 28.32 ± 0.48 3.54 ± 0.11abcdfghi 3.12 ± 0.17abcdfghi 2.94 ± 0.04abcdfghi 65.62 ± 0.98 1702.26 ± 1.48cdhi

3.12 ± 0.07abdfgi 28.96 ± 0.52 2.81 ± 0.13abcdefghij 2.94 ± 0.16 abcdfghi 2.24 ± 0.08abcdefghij 65.86 ± 0.76 1689.43 ± 1.56bcdeghij

Means ± SE (N=3). aSignificance at (p < 0.01) between untreated and treated seeds. b–eSignificance at (p < 0.01) between the treated seeds. f Significance at (p < 0.05) between untreated and treated seeds. g–j Significance at (p < 0.05) between the treated seeds.

maize and wheat flours were irradiated at 7.5 kGy. The other EAA (threonine, valine, isoleucine, leucine, tyrosine, phenylalanine and tryptophan) showed a dose-dependent decline, comparable with FAO/WHO (1991) reference pattern. Ismat et al. (2013) reported that radiation of raw flour of the sorghum cultivar at 5, 10 and 15 kGy decreased the level of all amino acids except for leucine, phenylalanine and tyrosine with a concomitant decrease in amino acid score except for that of leucine, phenylalanine and tyrosine. The application of gamma irradiation did not have a positive effect on the amino acids of the pigeon pea flour; it showed a significant (p < 0.05) reduction at all the delivered doses (Bamidele and Akanbi, 2015). Joseph et al. (2005) reported that, with the exception of tyrosine (which increased significantly), the amino acids in cowpea (acidic, basic, polar and nonpolar amino acids) were decreased significantly with the increase of gamma irradiation compared to their respective control. The changes in the concentration of amino acids induced by irradiation may probably be due to free radicals that might be formed in association with splitting of the peptide bonds, deamination and decarboxylation reactions of amino acids followed by chains of chemical reactions forming other new radicals (Elias and Cohen, 1977). These results clearly revealed that although gamma irradiation decreased the EAA of V. aconitifolia seeds, the EAA of irradiated seeds meet the standard nutritional requirement.

(Sangronis and Machado, 2007), Dolichos trilobus, Rhynchosia suaveolens, Tamarindus indica and Teramnus labialis (Arinathan et al., 2009), Vigna radiata, V. mungo (Kakati et al., 2010) and V. mungo varieties (Tresina et al., 2010) and Lablab purpureus varieties (Kala et al., 2010). In an earlier report, niacin content diminished significantly in mung bean treated with gamma irradiation (Khattak and Klopfenstein, 1989). The niacin and ascorbic acid content of gamma irradiated V. aconitifolia seeds were found to be higher than that of gamma irradiated V. unguiculata subsp. unguiculata seeds (Tresina and Mohan, 2011). 3.3. Amino acid analyses The amino acid profiles of raw and irradiated V. aconitifolia seeds is presented in Table 3. The content of sulphur containing amino acid V. aconitifolia seem to be deficient whereas other essential amino acids were found to be higher when compared to the FAO/WHO (1991) requirement pattern. Gamma irradiation has a slight effect on the amino acid profiles at recommended doses of foods (WHO, 1999). Khattak and Klopfenstein (1989) reported that sulphur amino acids in legumes are highly susceptible to irradiation. Although a dosedependent decrease in the sulphur amino acid was evident. Wang and Vonsonntage (1991) reported that sulphur-containing as well as aromatic amino acids are, in general, the most sensitive to irradiation, while simple amino acids could be formed by destruction of other amino acids. In the present study, legumes are found to possess high amounts of lysine (Jansman, 1996). Raw V. aconitifolia seeds (6.34 g 100 g−1) showed a dose-dependent decrease in lysine on irradiation (2–25 kGy, 5.26–4.76 g 100 g−1). Hooshmand and Klopfenstein (1995) wrote that lysine content decreased by 7% and 13% respectively, when

3.4. In vitro protein digestibility Table 4 presents the EAA, IVPD and PDCAAS of V. aconitifolia seeds. Cystine and methionine were the limiting amino acids in raw seeds, which further slightly decreased on irradiation. The dosedependent increase in IVPD on irradiation which can be attributed to

Table 2 Mineral composition and vitamin (niacin and ascorbic acid) content of Vigna aconitifolia seeds untreated and treated with gamma irradiation (g 100 g−1). Components

Sodium Potassium Calcium Magnesium Phosphorus Iron Zinc Copper Manganese Na/K Ca/P Niacin mg 100 g-1 Ascorbic acid mg 100 g-1

Dose Raw

2 kGy

5 kGy

10 kGy

15 kGy

25 kGy

34.06 ± 0.36 2256.68 ± 1.74 244.10 ± 1.72 214.04 ± 0.46 174.26 ± 0.66 7.46 ± 0.12 1.41 ± 0.09 0.76 ± 0.03 1.61 ± 0.04 0.02 1.40 28.08 ± 1.09 59.10 ± 0.64

32.06 ± 0.12af 2152.78 ± 1.26af 243.00 ± 0.98 204.01 ± 1.56af 172.06 ± 0.48af 6.98 ± 0.14af 1.11 ± 0.01af 0.74 ± 0.01a 1.51 ± 0.02af 0.02 1.14 27.36 ± 0.92 af 58.72 ± 1.21

31.04 ± 0.31abfg 2138.12 ± 1.58abfg 233.10 ± 1.22abf 201.06 ± 1.31abfg 170.16 ± 0.82abfg 6.33 ± 0.03 abfg 1.02 ± 0.01 abf 0.71 ± 0.02 abfg 1.49 ± 0.01 abf 0.02 1.37 27.04 ± 0.87abfg 58.10 ± 0.38af

30.78 ± 0.38abcfgh 2136.32 ± 1.78abcfgh 228.08 ± 1.21abcfgh 198.24 ± 1.48abcfgh 168.42 ± 0.76 abcfgh 6.21 ± 0.04abcfgh 0.98 ± 0.02abcfgh 0.71 ± 0.02abfg 1.44 ± 0.08a 0.01 1.35 25.13 ± 0.56abcfgh 56.64 ± 0.56abcfgh

30.36 ± 0.14abcdfgh 2122.11 ± 2.21abcdfghi 222.14 ± 0.78abcdfghi 196.11 ± 1.32abcdfghi 169.22 ± 0.58 abcfghi 6.28 ± 0.11abcfg 0.96 ± 0.03abcdfgh 0.68 ± 0.02abcdfgi 1.38 ± 0.03 abcfgh 0.01 1.31 24.33 ± 1.01abcfghi 51.03 ± 0.76abcdfghi

29.2.36 ± 0.24abcdefghij 2108.26 ± 2.36abcdefghij 214.07 ± 0.82abcdefghij 194.24 ± 1.65abcdefghij 167.24 ± 0.33abcdefghij 6.28 ± 0.07abfg 0.92 ± 0.03 abcdfghi 0.68 ± 0.03bcdghij 1.37 ± 0.05abcdfgh 0.01 1.28 22.06 ± 0.97abcdefghij 49.05 ± 0.78abcdefghij

Means ± SE (N=3). aSignificance at (p < 0.05) between untreated and treated seeds. b–eSignificance at (p < 0.05) between the treated seeds. f Significance at (p < 0.05) between untreated and treated seeds. g–j Significance at (p < 0.05) between the treated seeds.

33

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

Table 3 Amino acid profiles of acid- hydrolysed, purified seed proteins of Vigna aconitifolia seeds untreated and treated with gamma irradiation (g 100 g−1).a Amino acid

Glutamic acid Aspartic acid Serine Threonine Proline Alanine Glycine Valine Cystine Methionine Isoleucine Leucine Tryosine Phenylalanine Lysine Histidine Tryptophan Arginine a

Dose

FAO/WHO 1991 requirement pattern

Raw

2 kGy

5 kGy

10 kGy

15 kGy

25 kGy

16.12 10.64 4.36 3.96 3.33 3.68 3.08 5.16 0.64 1.62 4.16 7.42 3.14 5.48 6.34 2.76 1.24 6.14

15.21 8.68 4.01 3.11 3.06 3.14 2.98 4.78 0.56 1.52 3.98 6.36 3.08 5.10 5.26 2.11 1.01 5.50

14.68 8.31 3.84 3.44 2.96 3.36 2.76 4.68 0.55 1.68 3.24 6.54 2.94 4.38 5.11 2.08 0.96 5.46

12.36 8.20 3.76 3.28 3.08 3.54 2.78 4.76 0.53 1.62 3.38 6.38 2.92 4.56 5.08 2.11 0.94 5.38

11.36 8.11 3.44 3.43 2.88 3.12 2.68 4.54 0.53 1.58 3.49 6.56 2.96 4.38 4.89 2.32 0.92 5.42

11.26 8.06 3.26 3.46 2.86 3.08 2.61 4.36 0.54 1.59 3.24 6.58 2.96 4.26 4.76 2.14 0.92 5.46

3.4

3.5 2.5 2.8 6.6 6.3 5.8 1.9 1.1

All values are of single determinations.

these prostaglandins includes lowering of blood pressure and constriction of smooth muscle (Aurand et al., 1987). Linoleic and linolenic acids are the most important essential fatty acids required for growth, physiological functions and maintenance (Pugalenthi et al., 2004). Most of the fatty acids were unsaturated fatty acids, while saturated fatty acids (mainly, palmitic acid) contributed little of the total fatty acids content. Unsaturated fatty acids play an important role in lowering the risk of cardiovascular disease (Ezeagu et al., 1998; Vles and Gottenhos, 1989). The fatty acid composition and high amount of unsaturated fatty acids make V. aconitifolia a special legume suitable for nutritional applications. Irradiation of V. aconitifolia seeds revealed a decrease in the concentration of unsaturated fatty acids. However, linoleic acid, palmitoleic acid and eicosenoic acid increased after irradiation at 25 kGy. Saturated fatty acids detected were reduced after irradiation. This is in agreement with the earlier report in Mucuna pruriens (Bhat et al., 2008).

the degradation of proteins into fractions susceptible to enzymes or partial destruction of trypsin inhibitors. Similarly, decrease in some of the major antinutrients (eg. Phenols, phytates and lectins) might have contributed to increase of IVPD. Tresina and Mohan (2011) correlated the elevated IVPD of V.unguiculata subsp. unguiculata with decreased antinutrients. The PDCAAS also revealed a dose-dependent decrease on irradiation, indicating the limitation of available amino acids on digestion with enzymes.

3.5. Fatty acid analyses The fatty acid compositions of raw and gamma irradiated V. aconitifolia seeds are presented in Table 5. Fatty acid profiles of V. aconitifolia seeds reveal lipids as a good source of the nutritionally essential linoleic and oleic acids. Linoleic acid was the dominating fatty acid followed by linolenic acid, oleic acid and palmitic acid. The nutritional value of linoleic acid is due to its metabolism at tissue levels which produce the hormone like prostaglandins. The activity of

Table 4 EAAS of acid- hydrolysed, purified seed proteins, IVPD and PDCAAS of Vigna aconitifolia seeds untreated and treated with gamma irradiation. EAA

Threonine Valine Cystine + Methionine Isoleucine Leucine Tryosine + Phenylalanine Lysine Histidine Tryptophan IVPD % PDCAAS % Threonine Valine Cystine + Methionine Isoleucine Leucine Tryosine + Phenylalanine Lysine Histidine Tryptophan

Dose Raw

2 kGy

5 kGy

10 kGy

15 kGy

25 kGy

116.47 151.76 90.4 148.57 112.42 136.82 109.31 145.26 112.72 69.32 ± 1.04

91.47 136.57 83.2 142.14 96.36 129.84 90.69 111.05 91.82 72.14 ± 1.38

101.18 133.71 89.2 115.71 99.09 116.19 88.10 109.47 89.27 75.36 ± 1.26

96.47 136.00 86.00 120.71 96.67 118.73 87.59 111.05 85.46 78.64 ± 1.54

100.88 129.70 84.40 124.64 99.39 116.51 84.31 122.14 83.64 81.08 ± 1.68

101.77 124.60 85.20 115.71 99.69 114.60 82.07 112.63 83.64 84.41 ± 0.94

80.74 102.20 62.67 102.99 77.93 94.85 75.77 100.70 78.14

65.99 98.52 60.02 102.54 69.52 93.67 65.42 80.11 66.24

76.25 100.77 67.22 87.20 74.67 89.48 66.39 82.50 65.77

75.86 106.95 67.63 94.93 76.02 93.37 68.88 87.33 67.81

81.80 105.17 68.43 101.06 80.59 94.46 68.36 99.00 67.81

85.90 105.15 71.92 97.67 84.15 96.74 66.54 95.72 70.60

34

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

Niely, 2007). In the currently investigated seeds, the content of nonproteinaceous amino acid, L-DOPA showed a significant (p < 0.05, p < 0.01) dose-dependent decline. These results were in consonance with the earlier report on Mucuna beans (Bhat et al., 2008). A significant (p < 0.05, p < 0.01) dose-dependent turn-down was recorded in the phytic acid content. Duodu et al. (1999) indicated that phytic acid degradation by irradiation is due to cleavage in the structure of phytic acid itself, which may also be true in the present study. Kaisey et al. (2003) reported that gamma irradiated broad bean seeds reduced the phytic acid content. The values of total free phenolics, tannins, L-DOPA and phytic acid of both unirradiated and irradiated V. aconitifolia seeds were found to be elevated when compared to an earlier report in gamma irradiated V. unguiculata subsp. unguiculata seeds (Tresina and Mohan, 2011). Hydrogen cyanide is known to cause acute or chronic toxicity. Hydrogen cyanide of V. aconitifolia seeds showed a significant (p < 0.05, p < 0.01) dose-dependent decrement in gamma irradiated seeds than the unirradiated seeds. The trypsin inhibitor activity of the currently examined unirradiated tribal pulse was higher than that of Phaseolus vulgaris Roba variety (4.59 mg/g) (Shimelis and Rakshit, 2007); Cicer arietinum (11.90 mg/g) (Alajaji and El-Adawy, 2006); Phaseolus vulgaris (white and black beans), Cajanus cajan (4.13–4.75 mg/g) (Sangronis and Machado, 2007). Irradiation resulted in a dose- dependent attenuation of trypsin inhibitor activity which was significant (p < 0.05, p < 0.01). The results point out that the maximum reduction in the value of trypsin inhibitor activity was observed at 25kGy. Inactivation of trypsin inhibitor in irradiated samples could be attributed to the destruction of disulphide (-S-S-) groups (El-Morsi et al., 1992). Irradiating seeds with gamma rays significantly (p < 0.05, p < 0.01) curtailed the levels of oligosaccharides dose-dependently. The oligosaccharide contents were inactivated to a considerable extent when legume samples were irradiated (Siddhuraju et al., 2002a, 2002b). In case of broad bean, a complete destruction of raffinose and stachyose was observed at 7.5 kGy radiation dose (Kaisey et al., 2003). The greater degradation of oligosaccharides in irradiated legumes could be a radiation-related phenomenon or due to enhanced activity of the associated degradative enzymes (Machaiah and Pednekar, 2002) and gamma irradiation may break glycosidic linkages in oligosaccharides to produce more sucrose and decrease the content of oligosaccharides (Dixit et al., 2011). Concerning phytohaemagglutinating activity, the human erythrocytes of ‘B’ blood group registered highest level of phytohaemagglutinating activity in both unirradiated and irradiated seeds when compared to ‘A’ blood group and ‘O’ blood group. Blood group ‘O’ in our study show evidence of much lower activity than did other blood groups. In earlier study, when soybean was subjected to radiation dose of 10 kGy, the phytohaemagglutinating

Table 5 Fatty acid profile of lipids of Vigna aconitifolia seeds untreated and treated with gamma irradiation.a Fatty acid (%)

Myristic acid (C14:0) Palmitic acid (C16:0) Palmitoleic acid (C16:1) Stearic acid (C18:0) Oleic acid (C18:1) Linoleic acid (C18:2) Linolenic acid (C18:3) Eicosenoic acid (C20:1) Sum of saturated fatty acid Sum of polyunsaturated fatty acid Polyunsaturated fatty acid/saturated fatty acid ratio a

Dose Raw

2 kGy

5 kGy

10 kGy

15 kGy

25 kGy

2.24 16.46 9.21 7.04 18.04 22.06 20.14 4.18 25.74

2.18 13.21 9.08 3.01 16.31 20.30 18.36 4.06 18.40

2.01 12.06 8.88 3.04 12.30 19.38 14.21 3.96 17.11

1.96 12.11 9.24 3.88 10.38 23.68 12.26 3.82 17.95

1.82 12.88 9.36 3.28 8.24 24.38 12.01 4.81 17.98

1.76 13.36 9.58 3.44 6.34 28.36 11.04 4.89 18.56

73.63

68.11

58.63

59.38

58.80

60.21

2.86

3.70

3.43

3.31

3.27

3.24

Average values of two determinations.

3.6. Analyses of antinutritional factors The usefulness of legumes is reduced since their concentrated protein is associated with antinutritional substances (Liener, 1994). Table 6 depicts the data related to antinutritional factors. A definite significant (p > 0.05, p > 0.01) dose-dependent hike of total free phenolics was observed in the currently investigated tribal pulse. Bhat et al. (2007) attributed such increase in phenolics to higher extractability by depolymerization and dissolution of cell wall polysaccharide by irradiation. However, irradiation is known to increase the activity of phenylalanine ammonia-lyase which is responsible for the synthesis of phenolic compounds. Siddhuraju et al. (2002b, 2002c) found increased phenolics in Sesbania and Vigna radiata seeds on soaking, followed by irradiation. The tannin content showed a significant (p > 0.05, p > 0.01) dose-dependent enhancement except 15 kGy. Elevation of tannins in V. aconitifolia seeds by gamma irradiation may be attributed to their higher extractability. Similar results were earlier noted in gamma irradiated Mucuna pruriens seeds (Bhat et al., 2008). Some reports indicate that irradiation decreases tannins in seeds (Villavicencio et al., 2000). The gamma irradiated V. aconitifolia seeds at a dose level of 5 kGy and 10 kGy had low level of phenols and tannins when compared to gamma irradiated peas, cowpeas, lentils, kidney beans and chick peas at a dose level of 5 kGy and 10 kGy (El-

Table 6 Data on antinutritional factors of Vigna aconitifolia seeds untreated and treated with gamma irradiation. Component

Total Free Phenolics (g100 g-1) Tannins (g100 g-1) -1 L-DOPA (g100g ) Phytic acid (mg100 g-1) Hydrogen cyanide(mg100 g-1) Trypsin inhibitor activity (TIU mg-1 protein) Oligosaccharides (g100 g-1) Raffinose Stachyose Verbascose Phytohaemagglutinating activity*(Hu mg-1 protein) A B O

Dose Raw

2 kGy

5 kGy

10 kGy

15 kGy

25 kGy

1.46 ± 0.12 0.65 ± 0.05 3.27 ± 0.68 421.38 ± 1.54 0.32 ± 0.04 28.30 ± 0.09 0.54 ± 0.26

1.50 ± 0.11af 0.69 ± 0.07af 2.97 ± 0.58af 394.08 ± 1.24af 0.26 ± 0.03af 24.12 ± 0.17af 0.49 ± 0.11

1.76 ± 0.09abfg 0.74 ± 0.03abfg 2.54 ± 0.46abfg 324.16 ± 1.06abfg 0.24 ± 0.03af 21.10 ± 0.28abfg 0.36 ± 0.04g

1.84 ± 0.07abcfgh 0.88 ± 0.06abcfgh 2.11 ± 0.17fg 272.56 ± 1.34abcfgh 0.22 ± 0.04bcgh 17.21 ± 0.15abcfgh 0.31 ± 0.03cgh

1.91 ± 0.13abcdfghi 0.96 ± 0.04 1.54 ± 0.11abcdfghi 214.61 ± 1.26abcdfghi 0.19 ± 0.03adfi 15.40 ± 0.36abcdfghi 0.24 ± 0.07bcghi

2.12 ± 0.17abcdefghij 1.01 ± 0.11abcdefghij 1.06 ± 0.09abcdefghij 156.48 ± 1.34abcdefghij 0.16 ± 0.04bceghj 13.16 ± 0.41abcdefghij 0.14 ± 0.01bcdeghij

1.68 ± 0.07 1.26 ± 0.14 32 133 18

1.31 ± 0.15af 0.94 ± 0.11af 28 119 14

1.10 ± 0.09abfg 0.91 ± 0.26af 21 92 09

0.74 ± 0.06abcfgh 0.54 ± 0.13abcfgh 18 70 03

0.48 ± 0.07abcdfghi 0.42 ± 0.07abfghi 13 51 02

0.24 ± 0.05abcdefghij 0.21 ± 0.03abcdefghij 09 27 Nil

Means ± SE (N=3). *Values are means of two determinations. aSignificance at (p < 0.01) between untreated and treated seeds. Significance at (p < 0.05) between untreated and treated seeds. g–j Significance at (p < 0.05) between the treated seeds.

35

b–e

Significance at (p < 0.01) between the treated seeds. f

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

cultivars. Cereal Chem. 53, 583–597. Bazzano, L.A., He, J., Ogden, L.G., Loria, C., Vupputuri, S., Myers, L., et al., 2001. Legume consumption and risk of coronary heart disease in US men and women. NHANES I epidemiologic follow-up study. Arch. Int. Med. 161, 2573–2578. Bazzano, L.A., Tees, M.T., Nguyen, C.H., 2008. Effect of non-soy legume consumption on cholesterol levels: A meta-analysis of randomized controlled trials. Circulation 118, S 1122, (Abstract 3272). Bell, S.J., Sears, B., 2003. Low-glycemic-load diets: Impact on obesity and chronic diseases. Crit. Rev. Food Sci. Nutr. 43, 357–377. Bhat, R., Sridhar, R.K., 2008. Nutritional quality evaluation of electron beam-irradiated lotus (Nelumbo nucifera) seeds. Food Chem. 107, 174–184. Bhat, R., Sridhar, K.R., Yokotani, K.T., 2007. Effect of ionizing radiation on antinutritional features of velvet bean seeds (Mucuna pruriens). Food Chem. 103, 860–866. Bhat, R., Sridhar, K.R., Seena, S., 2008. Nutritional quality evaluation of velvet bean seeds (Mucuna pruriens) exposed to gamma irradiation. Int. J. Food Sci. Nutr. 59, 261–278. Brain, K.R., 1976. Accumulation of L-DOPA in cultures from Mucuna pruriens. Plant Sci. Lett. 7, 157–161. Bravo, L., Siddhuraju, P., Calixto, F.S., 1999. Composition of underexploited Indian pulses. Comparison with common legumes. Food Chem. 64, 185–192. Bray, H.G., Thorne, W.V., 1954. Analysis of phenolic compounds methods. Biochem. Anal. 1, 27–52. Burns, R.B., 1971. Methods of estimation of tannin in the grain, sorghum. Agron. J. 63, 511–512. DAFNE, Data Food Networking, 2009. Pan-European Food Data Bank Based on Household Budget Surveys. Available on-line at: 〈http://www.nut.uoa.gr/ Dafnesoftweb〉 (Accessed 16 August 2009). Dickman, S.R., Bray, R.H., 1940. Colorimetric determination of phosphate. Ind. Eng. Chem. Anal. Ed. 12, 665–668. Dixit, A.K., Kumar, V., Rani, A., Manjaya, J.G., Bhatnagar, D., 2011. Effect of gamma irradiation on lipoxygenases, trypsin inhibitor, raffinose family oligosaccharides and nutritional factors of different seed coat coloured soybean (Glycine max L.). Rad. Phys. Chem. 80, 597–603. Duodu, K.G., Minnaar, A., Taylor, J.R.N., 1999. Effect of cooking and irradiation on the labile vitamin and antinutrients content of a traditional African sorghum porridge and spinach relish. Food Chem. 66, 21–27. Elias, P.S., Cohen, A.J., 1977. Radiation Chemistry of Major Food Compounds. Elsevier Biomedical, Netherland. El-Morsi, E.R., Abdel-Salam, H.S., Ismail, H.A., Aboul-Fetouch, S.A., Fawzay, A.M., 1992. Effect of gamma irradiation on trypsin inhibitor and subunit structure of proteins in field bean (Vicia faba) seeds during germination. Min. J. Agric. Res. Dev. 14, 849–871. El-Niely, H.F.G., 2007. Effect of radiation processing on antinutrients, in vitro protein digestibility and protein efficiency ratio bioassay of legume seeds. Rad. Phys. Chem. 76, 1050–1057. Ezeagu, I.E., Petzke, K.J., Lange, E., Metgea, C.C., 1998. Fat content and fatty acid composition of oils extracted from selected wild gathered tropical plant seeds from Nigeria. J. Am. Oil Chemists’ Soc. 75, 1031–1035. FAO/WHO, 2001. Human Vitamin and Mineral Requirements. Report of a joint FAO/ WHO Expert Consultation, Bangkok, Thailand. FAO/WHO, 1991. Protein Quality Evaluation. Food and Agricultural Organization of the United Nations, Roe, Italy, 66. Farag, M.D.E.H., 1989. Radiation deactivation of antinutritional factors: trypsin inhibitor and haemagglutinin in soybeans. Egypt. J. Rad. Sci. Appl. 6, 207–215. Folch, J., Lees, M., Solane-Stanly, G.M., 1957. A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. Chem. 226, 497–506. Geil, P.B., Anderson, J.W., 1994. Nutrition and health implications of dry beans: a review. J. Am. Coll. Nutr. 13, 549–558. Hooshmand, H., Klopfenstein, C.F., 1995. Effect of gamma irradiation on the mycotoxin disappearance and amino acid contents of corn, wheat and soybeans with different moisture contents. Plant Foods Hum. Nutr. 47, 227–238. Hsu, H.W., Vavak, D.L., Satterlee, L.D., Miller, G.A., 1977. A multi-enzyme technique for estimating protein digestibility. J. Food Sci. 42, 1269–1271. Humphries, E.C., 1956. Mineral composition and ash analysis. In: Peach, K., Tracey, M.V. (Eds.), Modern Methods of Plant Analysis Vol.1. Springer-Verlag, Berlin, 468–502. Ismat, G.A., Khogali, E.A., Azhari, O.A., Babiker, E.E., 2013. Effect of radiation process followed by traditional treatments on nutritional and antinutritional attributes of sorghum cultivar. Int. Food Res. J. 20, 3221–3228. Issac, R.A., Johnson, W.C., 1975. Collaborative study of wet and dry techniques for the elemental analysis of plant tissue by atomic absorption spectrophotometer. J. Assoc. Off. Anal. Chem. 58, 436–440. Jabeen, N.M., Kola, M., Reddy, K.J., 2015. Impact of irradiation on nutritional quality and functional properties of soy flour and sprouted soy floour. Int. J. Adv. Res. 3, 1120–1129. Jackson, M-L., 1967. Cyanide in plant tissue. In: Soil Chemical Analysis. Asia Publishing House, New Delhi India, pp. 337. Janardhanan, K., Gurumoorthi, P., Pugalenthi, M., 2003. Nutritional potential of five accessions of a South Indian tribal pulse Mucuna pruriens var. utilis. I. The effect of processing methods on the content of L-Dopa, phytic acid and oligosaccharides. Trop. Subtrop. Agroecosyst. 1, 141–152. Jansman, A.J.M., 1996. Bioavailability of proteins in legume seeds. Grain Legumes (AEP) 11, 19. Joseph, O.A., Klasus, M., Kwaku, D., Amanda, M., 2005. Functional properties of cowpea (Vigna unguiculata L. Walp) flours and pastes as affected by γ - irradiation. Food

activity was reduced by 50% (Farag, 1989) which was a significant reduction than the normal processing techniques such as germination, soaking and dehulling (Liener, 1994). The phytohaemagglutinating activity of the presently investigated underutilized legume was found to be lower when compared to gamma irradiated Vigna unguiculata subsp. unguiculata seeds (Tresina and Mohan, 2011). Our present work exposed a non-significant (p > 0.05, p > 0.01) and rapid dosedependent amplification in the in vitro protein digestibility activity. However, these values were higher when compared to the earlier reports of Bhat et al. (2008) in Mucuna bean seeds. The gamma irradiated V. aconitifolia seeds at a dose level of 5 kGy and 10 kGy had a high level of in vitro protein digestibility activity than gamma irradiated cowpeas and lentils of the same dose (El-Niely, 2007) and gamma irradiated V. unguiculata subsp. unguiculata seeds (Tresina and Mohan, 2011). 4. Conclusions From the current database, it is evident that Vigna aconitifolia seeds are a valuable source of nutrition due to high protein and carbohydrate with an adequate quantity of minerals, vitamins (niacin and ascorbic acid), essential amino acids and unsaturated fatty acids. The currently investigated tribal pulse possesses a variety of antinutritional factors which may/may not affect the consumers. Concerning the necessity of cutback in antinutritional factors in raw V. aconitifolia seeds in food and industrial uses, further studies have to be initiated to standardize an appropriate gamma irradiation dose required to ensure maximum benefits of V. aconitifolia seeds and their products. The outcome of the current study substantiates the aptness of employing gamma irradiation exposure for the diminution of antinutritional attributes in V. aconitifolia seeds and other legumes. Acknowledgement The authors are grateful to Dr. B. Venkatraman, Head, Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakam, Tamil Nadu, for his assistance in irradiating the seed samples. References Adebowale, K.O., Lawal, O.S., 2004. Comparative study of the functional properties of bambarra groundnut (Voandzeia subterranean), jack bean (Canavalia ensiformis) and Mucuna bean (Mucuna pruriens) flours. Food Res. Int. 376, 355–365. Alajaji, S.A., El-Adawy, T.A., 2006. Nutritional composition of chick pea (Cicer arietinum as affected by microwave cooking and other traditional cooking methods. J. Food Comp. Anal. 19, 806–812. Almedia, N.G., Calderon de la Barca, A.M., Valencia, M.E., 1991. Effect of different heat treatments on the anti-nutritional activity of Phaseolus vulgaris (variety ojode Carbra) lectin. J. Agric. Food Chem. 39, 1627–1630. Amarowicz, R., Pegg, R.B., 2008. Legumes as a source of natural antioxidants. Eur. J. Lipid Sci. Technol. 110, 865–878. Anderson, J.W., Major, A.W., 2002. Pulses and lipaemia, short- and long-term effect: potential in the prevention of cardiovascular disease. Br. J. Nutr. 88 (Suppl. 3), S263–S271. Anonymous, 1991. Analytical detection methods for irradiated foods. A review of the current literature. IAEA – TECDOC – 587. IAEA, Vienna. AOAC, 2005. Official Methods of Analysis 18th ed.. Association of Official Analytical Chemists, Washington. DC. Arinathan, V., Mohan, V.R., Maruthupandian, A., Aathiperumalsami, T., 2009. Chemical evaluation of raw seeds of certain tribal pulses in Tamil Nadu, India. Trop. Subtrop. Agroecosyst. 10, 287–294. Aurand, L.W., Wood, A.E., Wells, M.R., 1987. Food Composition and Analysis. Van Nostrand Reinhold, New York. Balaogun, A.M., Fetuga, B.L., 1986. Chemical composition of some underexploited leguminous crop seeds in Nigeria. J. Agric. Food Chem. 34, 189–192. Bamidele, O.P., Akanbi, C.T., 2013. Influence of gamma irradiation on the nutritional and functional properties of pigeon pea (Cajanus cajan) flour. Afr. J. Food Sci. 7, 285–290. Bamidele, O.P., Akanbi, C.T., 2015. Effect of gamma irradiation on amino acid profile, minerals and some vitamins content in pigeon pea (Cajanus cajan) flour. Br. J. Appl. Sci. Tech. 5, 90–98. Basha, S.M.M., Cherry, J.P., Young, C.T., 1976. Changes in free amino acids, carbohydrates and proteins of maturity seeds from various peas (Arachis hypogaea)

36

Biocatalysis and Agricultural Biotechnology 10 (2017) 30–37

P.S. Tresina et al.

nutritional assessment of the less known pulses, Vigna aconitifolia (Jacq.) Marechal and Vigna vexillata (L.) A. rich. Plant Foods Hum. Nutr. 45, 103–111. Siddhuraju, P., Vijayakumari, K., Janardhanan, K., 1996. Chemical composition and protein quality of the little known legume velvet bean (Mucuna pruriens L. DC.). J. Agric. Food Chem. 44, 2636–2641. Siddhuraju, P., Becker, K., Makkar, H.P., 2001. Chemical composition, protein fractionation, essential amino acid potential and antimetabolic constituents of an unconventional legume, Gila bean (Entada phaseoloidesMerrill) seed kernelJ. Sci. Food Agric 82, 192–202. Siddhuraju, P., Makkar, H.P.S., Becker, K., 2002a. The effect of ionizing radiation on antinutritional factors and the nutritional value of plant materials with reference to human and animal food. Food Chem. 78, 187–205. Siddhuraju, P., Osoniyi, O., Makkar, H.P.S., Becker, K., 2002b. Effect of soaking and ionizing radiation on various antinutritional factors of seeds from different species of an unconventional legume, Sesbania and a common legume, green gram (Vigna radiata). Food Chem. 179, 273–281. Siddhuraju, P., Osoniyi, O., Makkar, H.P.S., Becker, K., 2002c. Effect of soaking and ionizing radiation on various antinutritional factors of seeds from different species of an unconventional legume, Mucuna pruriens var. utilis. J. Agric. Food Chem. 48, 6048–6060. Somiari, R.T., Balogh, E., 1993. Effect of soaking, cooking and alpha- galactoside treatment on the oligosaccharide content of cowpea flours. J. Sci. Food Agric. 61, 339–343. Spies, J.R., Chamber, D.C., 1949. Chemical determination of tryptophan in proleins. Anal. Chem. 21, 1249–1266. Talwar, G.P., Srivastava, L.M., Mudgil, K.D., 1989. Textbook of Biochemistry and Human Biology 2nd ed.. Prentice Halls of India Private Ltd, Connaught Circus, New Delhi, India. Tan, N.H., Rahim, Z.H.A., Khor, H.T., Wong, K.C., 1983. Winged bean (Psophocarpus tetragonolobus). tannin level, phytate content and haemagglutinating activity. J. Agric. Food Chem. 31, 916–917. Tanaka, M., Thanankul, D., Lee, T.C., Chichester, L.O., 1975. A simplified method for the quantitative determination of sucrose, raffinose and stachyose in legume seeds. J. Food Sci. 40, 1087–1088. Tresina, P.S., Mohan, V.R., 2011. Effect of gamma irradiation on physicochemical properties, proximate composition, vitamins and antinutritional factors of the tribal pulse Vigna unguiculata subsp. unguiculata. Int. J. Food Sci. Technol. 46, 1739–1746. Tresina, P.S., Kala, K.B., Mohan, V.R., Vadivel, V., 2010. The biochemical composition and nutritional potential of three varieties of Vigna mungo (L.) Hepper. Adv. Biores. 1, 6–16. Vadivel, V., Janardhanan, K., 2000. Chemical composition of the underutilized legume Cassia hirsuta L. Plant Foods Hum. Nutr. 55, 369–381. Vadivel, V., Pugalenthi, M., 2008. Removal of antinutritional/toxic substances and improvement in the protein digestibility of velvet bean (Mucuna pruriens) seeds during processing. J. Food Sci. Technol. 45, 242–246. Vijayakumari, P., Siddhuraju, P., Pugalenthi, M., Janardhanan, K., 1998. Effect of soaking and heat processing on the levels of antinutrients and digestible proteins in seeds of Vigna aconitifolia and Vigna sinensis. Food Chem. 63, 259–264. Villavicencio, A.I.C.H., Mancini-Filho, Jorge, Delincee, H., Greiner, R., 2000. Effect of irradiation on antinutrients (total phenolics, tannins and phytate) in Brazilian beans. Rad. Phys. Chem. 57, 289–293. Villegas, R., Gao, Y.T., Yang, G., Li, H.L., Elasy, T.A., Zheng, W., et al., 2008. Legume and soy food intake and the incidence of type 2 diabetes in the Shanghai Women's Health Study. Am. J. Clin. Nutr. 87, 162–167. Vles, R.O., Gottenbos, J.J., 1989. Nutritional characteristics and food uses of vegetable oils. In: Robblen, G., Downey, R.K., Ashri, A. (Eds.), Oil Crops of the World. McGraw Hill, NewYork, 36–86. Wang, D., Vonsonntage, C., 1991. Radiation industrial oxidation of phenylalanine. In: Proceeding of the workshop on recent advances on detection of irradiated foods, BRC Information. Chem. Anal. Comm. of the Eur. Comm., Brussels, pp. 212–217. Wheeler, E.L., Ferrel, R.E., 1971. A method for phytic acid determination in wheat and wheat fractions. Cereal Chem. 48, 312–320. WHO, 1999. High-dose irradiation: wholesomeness of food irradiated with doses above 10 kGy. Report of a Joint FAO/IAEA/WHO study group. WHO Tech. Rep. Ser. 890, Geneva, i-vi.

Chem. 93, 103–111. Kaisey, M.T.A.L., Alwan, A.K.H., Mohammad, M.H., Saeed, A.H., 2003. Effect of gamma irradiation on antinutritional factors in broad bean. Rad. Phys. Chem. 67, 493–496. Kakade, M.L., Rackis, J.J., McGhce, J.E., Puski, G., 1974. Determination of trypsin inhibitor activity of soy products: a collaborative analysis of an improved procedure. Cereal Chem. 51, (376-38). Kakati, P., Deka, S.C., Kotoki, D., Saikia, S., 2010. Effect of traditional methods of processing on the nutrient contents and some antinutritional factors in newly developed cultivars of green gram [Vigna radiata (L.) Wilezek] and black gram [Vigna mungo (L.) Hepper] of Assam. India Int. Food Res. J. 17, 377–384. Kala, K.B., Tresina Soris, P., Mohan, V.R., Vadivel, V., 2010. Nutrient and chemical evaluation of Lablab purpureus (L.) sweet. Adv. Biores. 1, 44–53. Kalogeropoulos, N., Chiou, A., Loannou, M., Karathanos, V.T., Hassapidou, M., Andrikopoulos, N.K., 2010. Nutritional evaluation and bioactive microconstituents (phytosterols, tocopherols, polyphenols, triterpenic acids) in cooked dry legumes usually consumed in Mediterranean countries. Food Chem. 121, 682–690. Khandelwal, S., Udipi, S.A., Ghugre, P., 2010. Polyphenols and tannins in Indian pulses: Effect of soaking, germination and pressure cooking. Food Res. Int. 43, 526–530. Khatoon, N., Prakash, J., 2006. Nutritional quality of microwave-cooked and pressurecooked legumes. Int. J. Food Sci. Nutr. 55, 441–448. Khattak, A.B., Klopfenstein, C.F., 1989. Effect of gamma irradiation on the nutritional quality of grain and legume. I. stability of niacin, thiamin and riboflavin. Cereal Chem. 66, 169–170. Leterme, P., 2002. Recommendations by health organizations for pulse consumption. Br. J. Nutr. 88, S239–S242. Li, B.W., Cardozo, M.S., 1994. Determination of total dietary fiber in foods and products with little or no starch, non-enzymatic gravimetric method: collaborative study. J. Assoc. Off. Anal. Chem. Int. 77, 687–689. Liddell, H.F., Saville, B., 1959. Colorimetric determination of cysteine. Analyst 84, 133–137. Liener, I.E., 1994. Implications of antinutritional components in soybean foods. Crit. Rev. Food Sci. Nutr. 34, 31–67. Loaharanu, P., 1994. Food irradiation in developing countries. A practice alternative. IAEA Bull. 36, 30–35. Machaiah, J.P., Pednekar, M.D., 2002. Carbohydrate composition of low dose radiationprocessed legumes and reduction in flatulence factors. Food Chem. 79, 293–301. Mathers, J.C., 2002. Pulses and carcinogenesis: potential for the prevention of colon, breast and other cancers. Br. J. Nutr. 88, S273–S279. Metcalfe, L.D., Schemitz, A.A., Pelka, J.R., 1966. Rapid preparation of fatty acid esters from lipids for gas chromatographic analysis. Anal. Chem. 38, 514–515. Muller, H.G., Tobin, G., 1980. Nutrition and Food Processing. Croom Helm Ltd, London. NRC/NAS, 1980. National Research Council Committee on Dietary Allowances. Recommended Dietary Allowances 9th ed.. National Academy of Science Press, Washington, DC, USA. Pugalenthi, M., Vadivel, V., Gurumoorthi, P., Janardhanan, K., 2004. Comparative nutritional assessment of little known legumes Tamarindus indica, Erythrina indica and Sesbania bispinosa. Trop. Subtrop. Agroecosyst. 4, 107–123. Rama Rao, M.V., Tara, M.R., Krishnan, C.K., 1974. Colorimetric estimation of tryptophan content of pulses. J. Food Sci. Technol. 11, 213–216. Rizkalla, S.W., Bellisle, F., Slama, G., 2002. Health benefits of low glycaemic index foods, such as pulses, in diabetic patients and healthy individuals. Br. J. Nutr. 88, S255–S262. Rochfort, S., Panozzo, J., 2007. Phytochemicals for health, the role of pulses. J. Agric. Food Chem. 55, 7981–7994. Sadasivam, S., Manickam, A., 1996. Biochemical Methods. New Age International (P) Limited Publishers, New Delhi, India. Sandev, S., Karaivanov, I., 1977. The composition and digestibility of irradiated roughage treatment with gamma irradiation. Tierernahr. Fuetterung 10, 238–242. Sangronis, E., Machado, C.J., 2007. Influence of germination on the nutritional quality of Phaseolus vulgaris and Cajanus cajan. LWT Food Sci. Technol. 40, 116–120. Sattar, A., Neelofar, Y., Akhtar, M.A., 1990. Effect of radiation and soaking on phytate content of soybean. Acta Aliment. 19, 331–336. Shimelis, E.A., Rakshit, S.K., 2007. Effect of processing on antinutrients and in vitro protein digestibility of kidney bean (Phaseolus vulgaris L.) varieties grown in east Africa. Food Chem. 103, 161–172. Siddhuraju, P., Vijayakumari, K., Janardhanan, K., 1994. Chemical analysis and

37