Electron spin resonance (ESR) spectroscopy was employed to detect free radicals in raw Mucuna pruriens (velvet bean) seeds after electron beam irradiation (Microtron source: 0, 2.5, 5, 7.5, 10, 15 and 30 kGy) and conventional processing (roasting, powdering and cooking). The ESR signal of irradiated seeds (g=2.0055±0.0001) was more prominent in the seed coat than cotyledon. Seed coat of irradiated samples showed dose-dependent linear increase of this signal (g = 2.0055) accompanied by a weak triplet (satellite peak; aH = 3 mT) produced exclusively by radiolysis and could be used as an indication of successful irradiation. Irradiated cotyledon portion devoid of satellite peak (triplet) showed a linear increase in signal intensity up to 10 kGy with a sharp decline at higher doses (15 and 30kGy). Stability of radiation-induced ESR signals after 6 months of storage (25 ± 1°C) revealed the presence of a weak triplet with a substantial loss of signal intensity. Thermal effects such as roasting and powdering of seeds increased the signal intensity (g = 2.0055) similar to or in greater proportion than irradiation. Phenolics in seeds, which contribute significantly to detect free radicals in vegetative parts of a plant showed a waning trend in seed coat, while it was vice versa in cotyledon. Textural studies revealed significant loss in firmness after irradiation (p<0.05), which might favour in minimising the cooking time. Results of the present study might help to divulge the beneficial effects of application of electron beam irradiation technology as a better alternative to fumigants in seed preservation for safety and quarantine purposes.
Adebowale K.O. and 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 Research International37: 355—365 .
2.
Ahenkora K. , Dadzie M. and Osei-Bonsu P. (1999). Composition and functional properties of raw and heat processed velvet bean (Mucuna pruriens (L.) DC. Var. utilis) flours . International Journal of Food Science and Technology34: 131—135 .
3.
Bayram G. and Delincée H. (2004). Identification of irradiated Turkish foodstuffs combining various physical detection methods . Food Control15: 81—91 .
4.
Bhushan B. , Bhat R. , Rao B.Y.K. , Ahmad R. and Bongirwar D.R. (2003a). Electron spin resonance studies on γ-irradiated coffee bean parts . International Journal of Food Science and Technology38: 11—16 .
5.
Bhushan B. , Bhat R. and Sharma A. (2003b). Status of free radicals in Indian monsooned coffee beans γ-irradiated for disinfestation . Journal of Agricultural and Food Chemistry51: 4960—4964 .
6.
Bruhn C.M. (2001). United States consumer choice of irradiated food . In: Loaharanu P. and Thomas P. (eds.), Irradiation for Food Safety and Quality. Lancaster (PE): USA, Technomic Publishing , pp. 169—173.
7.
Castell-Perez E. , Moreno M. , Rodriguez O. and Moreira R.G. (2004). Electron beam irradiation treatment of cantaloupes: effect on product quality . Food Science and Technology International10: 383—390 .
8.
Chabane S. , Pouliquen-Sonaglia I. and Raffi J. (2001). Detection of irradiated spices by different physical techniques. Canadian Journal of Physiology andPharmacology79: 103—108 .
9.
Cleland M.R. and Pageau G.M. (1985). Food Irradiation Processing. Vienna: IAEA — SM — 271/54, IAEA .
10.
D'Amour J. , Gosselin C. , Arul J. , Castaigne F. and Willemot C. (1993). Gamma radiation affects cell wall composition of strawberries . Journal of Food Science58: 182—185 .
11.
De Jesus E.F.O. , Rossi M. and Lopes R.T. (1999). An ESR study on identification of gamma irradiated kiwi, papaya and tomato using fruit pulp . International Journal of Food Science and Technology34: 173—178 .
12.
Delincée H. (1998). Detection of food treated with ionizing radiation . Trends in Food Science and Technology9: 73—82 .
13.
Desrosiers M.F. (1996). Current status of the EPR method to detect irradiated food . Applied Radiation and Isotopes47: 1621—1628 .
14.
Desrosiers M. , Bensen D. and Yaczko D. (1995). Commentary on `optimization of experimental parameters for the EPR detection of cellulosic radical in irradiated food stuffs '. International Journal of Food Science and Technology30: 675—680 .
15.
Dodd N.J.F. , Lea J.S. and Swallo J. (1989). The ESR detection of irradiated food . Applied Radiation Isotope40: 1211—1214 .
16.
En 1787. (2000). Foodstuffs, -Detection of Irradiated Food Containing Cellulose by ESR spectroscopy. Brussels , Belgium: European Committee for Standardization .
17.
Farkas J. (1998). Irradiation as method for decontaminating food - a review . International Journal of Food Microbiology44: 189—204 .
18.
Fricke H. and Hart E.J. (1966). Chemical dosimetry. In: Attix F.H. and Raesch W.C. (eds), Radiation Dosimetry. Vol. 2, New York: Academic Press , pp. 167—239.
19.
Fujii Y. , Shibuya T. and Yasuda T. (1992). L-3,4 dihydroxyphenylalanine as an allelochemical candidate from Mucuna pruriens (L.) DC. var. utilis. Agricultural Biology andChemistry55: 617—618 .
20.
Fukumoto L.R. and Mazza G.2000. Assessing antioxidant and prooxidant activities of phenolic compounds . Journal of Agricultural and Food Chemistry48: 3597—3604 .
21.
Goodman B.A. , McPhail D.B. and Duthie D.M.L. (1989). Electron spin resonance of some irradiated foodstuffs . Journal of Science of Food and Agriculture47: 101—111 .
22.
Guillon F. and Champ M. (1996). Grain legumes and transit in humans . Grain Legumes AEP11: 18 .
23.
Gurumoorthi P. , Pugalenthi M. and Janardhanan K. (2003). Nutritional potential of five accessions of a South Indian tribal pulse Mucuna pruriens var. utilis: II. Investigations on total phenolics, tannins, trypsin and chymotrypsin inhibitors, phytohaemagglutinins, and in vitro protein digestibility . Tropical and Subtropical Agroecosystems1: 153—158 .
24.
Hayashi T. (1998). Decontamination of dry food ingredients and seeds with soft electrons (low energy electrons) . Food Science and Technology International Tokyo4: 114—120 .
25.
Howard L.R. and Buescher R.W. (1989). Cell wall characteristics of gamma radiated refrigerated cucumber pickles . Journal of Food Science54: 1266—1268 .
26.
Hunter C. (2000). Changing attitudes to irradiation throughout the food chain. RadiationPhysics and Chemistry57: 239—243 .
27.
Iaea (2002). International Atomic Energy Agency, Clearance database Available: www.iaea.org/icgfi (2002).
28.
Kikuchi O.K. , Todoriki S. , Saito M. and Hayashi T. (2003). Efficacy of soft-electron (Low-energy Electron Beam) for soybean decontamination in comparison with gamma —rays . Journal of Food Science68: 649—652 .
29.
Kispéter J. , Kiss L.I. and Deelincée. ( 1996). It is possible to detect the irradiation treatment of Hungarian paprika after long-term storage? RadiationPhysics and Chemistry48: 384 .
30.
Loaharanu P. (1994). Food irradiation in developing courtiers: A practical alternative. IAEABulletin36: 30—35 .
31.
Maloney D.R. , Tabner B.J. , and Tabner V.A. (1992). An electron spin resonance study of some gamma irradiated fruits. RadiationPhysics and Chemistry39: 309—314 .
32.
Mondelaers W. (1998). Low energy electron accelerators in industry and applied research . Nuclear Instrumentation Methods B 139: 43—50 .
33.
Morris J.B. (1999). Legume Genetic Resources with Novel ``Value Added'' Industrial and Pharmaceutical Use. In: Janick J. (ed.), Reprinted from: Perspectives on New Crops and New Uses. Alexandria: ASHS Press , pp. 196—201.
34.
Oufedjikh H. , Mahrouz M. , Amiot M.J. and Lacroix, M. (2000). Effect of gamma-radiation on phenolic compounds and phenylalanine ammonia-lyase activity during storage in relation to peel injury from peel of Citrus clementina Hort. ex. Tanaka . Journal of Agricultural and Food Chemistry48: 559—565 .
35.
Pauli G.H. and Tarantino L.M. (1995). FDA regulatory aspects of food irradiation . Journal of Food Protection58: 209—212 .
36.
Pilbrow J.R. , Troup G.J. , Hutten D.R. and Hunter C.R. (1996). ESR detection of free radicals in gamma irradiated spices and other foodstuffs. In: Mc Murray C.H. , Stewart E.M. , Gray R. and Pearce J. (eds), Detection methods of irradiated Foods. Current Status . Cambridge , UK: The Royal Society of Chemistry , pp. 7—84.
37.
Prakash D. , Niranjan A. and Tewari S.K. (2001). Some nutritional properties of the seeds of three Mucuna species. International Journal of Food Sciences andNutrition52: 79—82 .
38.
Pratt D.E. (1992). Natural antioxidants from plant material. In: Phenolic Compounds in Food and their Effects on Health. (Volume II). Antioxidants and Cancer Prevention. Huang M.T. , Ho C.T. and Lee C. (eds.), ACS Symposium Series 507 . Washington, DC: American Chemical Society , pp. 54—71.
39.
Raffi J. (1998). Identifying irradiated foods . Trends in Analytical Chemistry17: 226—233 .
40.
Raffi J.J. and Agnel J.P.L. (1989). Electron spin resonance identification of irradiated fruits. RadiationPhysics and Chemistry34: 891—894 .
41.
Raffi J. , Fakirian A. and Lesgards G. (1994). Intêrets comparés de la resonance paramagnétique électronique et de la thermoluminescence pour l'identification de plantes aromatiques ioniées . Annales des Falsifications et de l'Expertise Chimique87: 125—134 .
42.
Raffi J. , Yordanov N.D. , Chabane S. , Douifi L. , Gancheva V. and Ivanova S. (2000). Identification of irradiation treatment of aromatic herbs, spices and fruits by electron paramagnetic resonance and thermoluminescence . Spectrochimica Acta Part A 56: 409—416 .
43.
Rajeshwar Y. , Senthil Kumar G.P. , Malaya Gupta and Upal Kanti Mazumder (2005). Studies on in vitro antioxidant activities of methanol extract of mucuna pruriens (Fabaceae) seeds . European Bulletin of Drug Research13: 31—39 .
44.
Rosset J. , Bärlocher F. and Oertli J.J. (1982). Decomposition of conifer needles and deciduous leaves in two Black Forest and two Swiss Jura streams . International Revue Gesamten Hydrobiologie67: 695—711 .
45.
Schutz H.G. , Bruhn C.M. and Diaz-Knauf K.V. (1989). Consumer attitude toward irradiated foods: effects of labeling and benefits information . Food Technology43: 80—86 .
46.
Siddhuraju P. , Vijayakumari K. and Janardhanan K. (1996). Chemical composition and protein quality of the little known legume Velvet bean (Mucuna pruriens L. DC.) . Journal of Agricultural and Food Chemistry44: 2636—2641 .
47.
Siddhuraju P. , Makkar H.P.S. and Becker K. (2002). The effect of ionizing radiation on antinutritional factors and the nutritional value of plant materials with reference to human and animal food- Review . Food Chemistry78: 187—205 .
48.
Siddhuraju P. , Osoniyi O. , Makkar H.P.S. and Becker K. (2002). 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 Chemistry79: 273—281 .
49.
Skerget M. , Kotnik P. , Hadolin M. , Hras A.R. , Simonic M. and Knez Z. (2005). Phenols, proanthocyanidins, flavones and flavonols in some plant materials and their antioxidant activities . Food Chemistry89: 191—198 .
50.
Stachowicz W. , Burlinska G. and Michalik J. (1998). EPR detection of foods preserved with ionizing radiation. RadiationPhysics and Chemistry52: 157—160 .
51.
Stevenson M.H. and Gray R. (1995). The use of ESR spectroscopy for the identification of irradiated food . Annual Reports on NMR Spectroscopy31: 123—142 .
52.
Stewart E.M. (2001). Detection methods for irradiated foods. In: Mollins R.A (ed.), Food Irradiation: Principles and applications. NewYork: John Wiley and Sons , pp. 347—386.
53.
Szocs E. (2002). Walnut free radicals studies by ESR . Journal of Food Science67: 953—955 .
54.
Tabata V. , Ito Y. and Tagawa S. (1991). Handbook of Radiation Chemistry. Boston M.A: CRC Press , pp. 605—720.
55.
Tripathy Y.B. and Upadhyay A.K. (2002). Effect of the alcohol extract of the seeds of Mucuna pruriens on free radicals and oxidative stress in albino rats . Phytother Research16: 534—538 .
56.
Uchiyama S. , Kawamura Y. and Saito Y. (1990). Identification of gamma irradiated spices by electron spin resonance (ESR) spectrometry . Journal of the Food Hygienic Society of Japan31: 499—507 .
57.
Variyar P.S. , Ahmad R. , Bhat R. , Niyas Z. and Sharma A. (2003). Flavoring components of raw monsooned arabica coffee and their changes during radiation processing . Journal of Agricultural and Food Chemistry51: 7945—7950 .
58.
Velioglu Y.S. , Mazza G. , Gao L. and Oomah B.D. (1998). Antioxidant activity and total phenolics in selected fruits, vegetables, and grain products . Journal of Agricultural and Food Chemistry46: 4113—4117 .
59.
Villavicencio A.L.C.H. , Mancini-Filho J. and Delincée H. (1998). Application of different techniques to identify the effects of irradiation on Brazilian beans after six months storage . Radiation Physics and Chemistry52: 161—166 .
60.
Warchalewski J.R. , Gralik J. , Zawirska-Wojtasia R. , Zabielski J. and Kuśnierz R. (1998). The evaluation of wheat grain odour and colour after gamma and microwave irradiation. Electronic Journal of Polish Agricultural Universities, FoodScience and Technology1: 1—11 .
61.
W.H.O. (1999). High dose irradiation: wholesomeness of food irradiated with dose above 10 kGy. Technical Report Series 890. Geneva .
