Abs tract: The aim of this st u d y wa s to evaluate the effect of gamma irradiation on phys ico-chemical properties of groundnut as well as to in v e s t igate its impact on quality attributes of groundnut oil. S e eds of two cultivars of ground nut (Arachis hypogaea) namely Sodari and Madani we re g a mmairradiated at dos e levels of 1, 1.5 and 2 kGys . Proximate compos ition, a s h min e ra ls , iodine value, acid value, peroxide value, s aponification value, oil refractive ind e x, oil relative vis cos ity, in-vitro protein diges tibility, nitrogen s olubility, water holding capacity, oil holding capacit y , b u lk d ens ity, emuls ion activity, emuls ion capacity, e mu ls io n s tability, foam capacity and foam s tability were determined for raw and irra d ia t e d s eeds . The res ults revealed that the effect of gamma irradiation on protein, oil, fiber, carbohydrates and minerals content of grou n d nut seeds was of no cons is tent pattern, however, for the quality attributes of groundnut oil, g amma irradiation caus ed significant d e c re ase (P# 0.05) in iodine value and s ignificant increas e in acid and peroxide values for b o t h cultivars , with exception of the acid value of Madani cultivar. W hile saponification value, refractive index and viscos ity of grou n dnut oil for both cultivars were not affected significantly by gamma irradiation. Moreo v e r, a s c ompared with untreated groundnut flour, for both cultivars , water holding c a pacity, bulk density, emuls ion activity and emuls ion capacity of groundnut flour were n o t s ignificantly affected by gamma irradiation. On the other hand, foaming s tability wa s a ffe c t e d negatively with gamma irradiation. Generally, s light differences between the two cultivars s tudied were obs erved for the different properties tes ted

A / Azim

A M Nour

Gammaa A M Osman

Shireen E A Hmed

CiteSeerX

Australian Journal of Bas ic and Applied Sciences , 3(3): 2856-2860, 2009
ISSN 1991-8178
 
Corresponding Author: A/Azim A.M. Nour, Dept. Food Sci. and Tech. Faculty of Agric. University of Khartoum.
Sudan
2856
Effect of Gamma Irradiation on the Physico-chemical Characterstics of
Groundnut (Arachis Hypogaea)
A/Azim A.M. Nour Shireen E.A Hmed, Gammaa A.M. Osman1 1 2
Dept. Food Sci. and Tech. Faculty of Agric. University of Khartoum. Sudan1
Environment and Natural Resources Research Institute, National Research Center, Sudan2
Abstract: The aim of this  s t u d y  wa s  to evaluate the effect of gamma irradiation on phys ico-chemical
properties  of groundnut as  well as  to in v e s t igate its  impact on quality attributes  of groundnut oil.
Se eds  of two cultivars  of ground nut (Arachis hypogaea) namely Sodari and Madani we re  g a mma  -
irradiated at dose levels  of 1, 1.5 and 2 kGys  . Proximate compos ition, a s h  min e ra ls , iodine value,
acid value, peroxide value, saponification value, oil refractive ind e x, oil relative viscos ity, in-vitro
protein diges tibility, nitrogen solubility, water holding capacity, oil holding capacit y , b u lk d ens ity,
emuls ion activity, emuls ion capacity, e mu ls io n  s tability, foam capacity and foam s tability were
determined for raw and irra d ia t e d seeds . The results  revealed that the effect of gamma irradiation on
protein, oil, fiber, carbohydrates  and minerals  content of grou n d nut seeds  was  of no cons is tent
pattern, however, for the quality attributes  of groundnut oil, g amma irradiation caused s ignificant
d e c re ase (P 0.05) in iodine value and s ignificant increase in acid and peroxide values  for b o t h
cultivars , with exception of the acid value of Madani cultivar. W hile saponification value, refractive
index and viscos ity of grou n dnut oil for both cultivars  were not affected s ignificantly by gamma
irradiation. Moreo v e r, a s  c ompared with untreated groundnut flour, for both cultivars , water holding
c a pacity, bulk density, emuls ion activity and emuls ion capacity of groundnut flour were  n o t
s ignificantly affected by gamma irradiation. On the other hand, foaming s tability wa s  a ffe c t e d
negatively with gamma irradiation. Generally, s light differences  between the two cultivars  s tudied were
observed for the different properties  tes ted.
Key words: Groundnut. gamma irradiation, groundnut oil, groundnut flour
INTRODUCTION
Groundnut (Arachis hypogeae L.) is  a leguminous , annual herb a c e o u s  plant belonging to the suborder
Papillionacea of the order Leguminacea, and grown mainly for their seeds . It is  one of the leading agricultural
crops  of the  wo rld  fo r t h e  production of edible plant oil and protein (Adegoke et al., 2004). Sudan is  one of
the major groundnut producing countries  in Afric a , t h e  a re a  o f production occupies  about 13 % of the total
cultivable land in the country ( Ishag, 1986).
In mos t of the develo p in g  c o u n t rie s , groundnut is  s tored as  dry seeds  and forms  an enormous  serve of
food; however, during s torage, vas t quantities  of seeds  are los t annually as  a result o f moulds  and insects
attacks  (Tripathi and Kumar,2007) Losses  of s tored seeds , caused by insects ' infes tation, such as  Caryedon
serratus, Bruchids  and Pyralids , are the mos t common s torage pes t ,  (Se mb e n e ,2006). On the other hand
groundnut is  among the major food commodities  that can be affected by mycotoxins  such as  aflatoxins  , which
are the toxic chemical s u b s tances  produced by toxigenic s train of fungi such as  Aspergillus flavus (Smith and
Ross ,1991), under specific conditions . Aflatoxins  and insect infes tation are the mos t important quality problems
in groundnut worldwide, with serous  health and economic implications  (IARC,1993).
Gamma radiation is  a phys ical technique of food preservation that seems to have a potential to protect such
commodity from insects  infes tation and microbial contamination during s torage (Taub et al., 1976; Rich; W HO,
1988). Therefore  it  h a s  b e e n  p roposed as  a good alternative to methyl bromide and other fumigants  for pes t
control (Gupta, 2001). However, development of this  technique involve cons ideration that gamma might change
the nutritive value of s tored seeds . The absolute relationship of radiation application dose and poss ible changes
must be known in order to comprehens ively assess  the acceptability of radiation – treated food seeds . This
paper was  intended to inves tigate some nutrition-related chemical changes  induced in peanut seeds  upon gamma
irradiation.
Aust. J. Basic & Appl. Sci., 3(3): 2856-2860, 2009
2857
MATERIALS AND METHODS
Materials:
Two groundnuts  ((Arachis hypogaea) cultivars  seeds , Madani and Sodari were obtained fro m the plant
breeding divis ion, Hudieba Research Station, Agricultural Research Corporation (ARC), Sudan. The seeds  were
shelled by hand and all kernels  samples  were s tored under ambient temperature during the s tudy. 
Methods: 
Irradiation process:
About 200 g lots  of the  groundnut seeds  were sealed in glass  bottles  prior and during irradiation process .
The samples  were irradiated at Kaila irradiation process ing unit, Su danese Atomic Energy Corporation (SAEC)
us ing an experimental cobalt- 60 gamma source (Nordion gamma cell 220 - Excell), irradiatio n  wa s  carried
out at room temperature, with the doses  of 1.0, 1.5 and 2 KGry. 
Non-irradiated seeds  serv e d  as  control. Irradiated and non- irradiated samples  of groundnut seeds  were
ground to pass  through 0.4 mm screen and kept in glass  bottles  at room temperature for analys is .
Proximate composition:
The level of mois ture, ash, crude protein, oil, crude fibe r a n d  c a rbohydrates  of the irradiated (1.0, 1.5 and
2.0 KGys) and non-irradiated groundnut seeds  were determined by the use of manual methods  as  o u t lin ed by
AOAC, (1990). Mineral extraction of the irradiated and non-irradiated groundnut seeds , was  prepared according
to the method described by Pearson (1981). 
Oil Quality Attributes:
The Iodine value, peroxide value and saponification value of the irra d ia t e d  and non-irradiated groundnut
oil were determined according to the Amer. Oil Chem. Soc. (AOCS, 1972). 
Functional properties:
The water retention capacity (W RC), oil absorption ca p a c it y  (OAC) and emuls ion capacity (EC) of the
irradiated and non-irradiated groundnut flour was  measured by a modified method of Beuchat (1977).  The bulk
dens ity was  determined by the method of Moreyra and Peleng (1981) 
Statistical Analysis:
A ll a n a ly s e s  were performed in triplicate (n = 3). The analys is  of variance was  performed to examine  t h e
s ignificant effect in all parameters  measured. The level of s ig n ific a n ce used was  95 % (Gomez and
Gomez,1984)
RESULTS AND DISCUSSION
Effect of Gamma Irradiation on Chemical Constituents:
The effect of gamma irradiation (0.0, 2.0 KGys) on mois ture, protein, oil, fiber, c a rb o h y drates  ash and ash
minera ls  c ontent of groundnut seeds  for both  Sodari and Madani cultivars  are presented in tables  1and 2,
The mois ture content was  not subs tantially affected by gamma irradiation treatment for both Sodari and Madani
cultivars . Similar findings  we re  o bserved by Rady et al. (2002) who reported that gamma irradiation has  no
real effect on mois ture cont e n t  o f o il seeds . Significant increase in protein and ash content (P  0.05) was
observed for Madani cultivar. W hile for Sodari cult iv a r t h e  c h ange was  of no s ignificant. However, oppos ite
results  were observed for that of oil content. Siddhuraji et al. (2002) and Seda et al. (2001) reported that
gamma irrad ia tion did not induce any change in protein and oil content of soybean and groundnut. On the
other hand s ignificant differences  were observed in fiber and carb ohydrates  content as  affected by irradiation.
W hile data of minerals  indicate that no apparent changes  in both cultivars .    
The divers ity of the observed effects  of gamma irradiation on different seeds  chemical cons tituents , for
the two cultivars , may be closely related to insects  and microbial infes tations  as  well a s  genetic factors , rather
than direct effect of radiation. Pos itive values  might result in part from insects  and microbial protection offered
by gamma irradiation. Ogbadu (1980) reported that aflatoxin B1 production decreased with increas ing gamma
irradiation dose in soy bean and groundnut. Many workers  reported that there have been chan ges  in chemical
compos ition of seeds  as  affected by insect infes tations  (Jood and Kapoor, 1993; Modgil, 2002). 
Aust. J. Basic & Appl. Sci., 3(3): 2856-2860, 2009
2858
Table 1: Effect of gamma irradiation on proximate composition of groundnut seeds   
T reated Dose Moisture Protein Oil Fiber Carbohydrates Ash
cultivars (Kgys) (%) (%) (%) (%) (%) (%)     
 
Sodari 0.0 3.56 25.80 50.40 2.66 8.88 2.54a c b a b b
2.0 3.67 24.43 52.50 2.40 19.08 2.59a c a b a b
Madani 0.0 3.40 25.84 53.00 2.73 15.40 2.59b c a  a c b 
2.0 3.43 29.75 53.00 2.49 11.94 2.82b a a b d a
SEM 0.10 0.11 0.26 0.11 0.29 0.04
Means in the same column with different letter (s) are significantly different (P 0.05) according to Least Significant T est (LSD)
SEM: standard error of means. 
Table 2: Effect of gamma irradiation on ash minerals content of groundnut flour (mg/100g)                  
T reated Irradiation dose
Minerals 
-----------------------------------------------------------------------------------------------------------------------------------
cultivars (0.0 Kgys) (1.0 Kgys) (1.5 Kgys) (2.0 Kgys) SEM          
   
Sodari Na 02.42 03.00 02.77 02.61 0.020 d  b  c  cd
K 05.00 15.00 17.85 16.25 0.044g  e  c  d
Ca 07.44 10.90 11.14 09.58 1.080 a  a  a  a
Mg 11.36 13.18 13.26 13.50 1.029 b  a  a  a
Zn 00.56 01.13 00.85 00.88 0.052 c  a  bc  bc
Mn 00.41 00.77 00.77 00.77 0.050 c  a  a  a
Cu 00.45 00.44 00.53 00.54 0.015d  d  c  c
Fe 02.38 03.33 03.93 05.70 0.090e  d  c  a
Madani Na 04.17 02.68 02.77 02.47 0.020 a  cd  c  b
K 8.62 16.25 21.25 13.75 0.044 b  d  a  f
Ca 10.81 11.46 09.75 10.92 1.080 a  a  a  a
Mg 13.23 13.63 13.75 13.42 1.029 a  a  a  a
Zn 00.85 00.91 00.34 00.73 0.052bc  b  d  c
Mn 00.56 00.76 00.64 00.58 0.050 b  a  ab b
Cu 00.93 00.40 00.66 00.52 0.015 a  d  b  c
Fe 04.47 04.47 04.36 02.64 0.090 b  b  b  e
Means in the same row with different letter (s) are significantly different (P 0.05) according to Least Significant T est (LSD)
SEM: standard error of means. 
Effect of Gamma Irradiation on Oil Quality Attributes:
The effect of gamma irradiation (0.0, and 2.0 KGys) on iodine value, acid value, peroxide value,
saponification value, refractive index and viscos ity  o f g ro u ndnut seed oils  for both cultivars  are illus trated in
table 3. The results  indicate that, irradiation caused a decrease in iodine value for both c u lt iv a rs ; however
chan g e  wa s  s ig n ificant for Madani cultivar. For acid and peroxide values , the irradiated samples  were higher
than that of non-irradiate d  o n e s  fo r Sodari, while for Madani no change was  observed. Similar findings  were
obtaine d  b y  Z e b  a n d  A hmed. (2004) who reported that, the iodine value of sunflower and soybean oil
decreased s ignificantly with high gamma radiation (1, 5 and20 KGy s ). while the acid values  were increased.
The decrease in iodine value may be attributed to the saturation of the double of unsaturated fatty acids  bonds
(Albashir, 2004). For saponification value, refractive index and relative viscos ity, no change was  observed
betwe e n  t h e irradiated and non-irradiated samples . This  finding agreed with that reported by Zeb and Ahmed
(2004).
Effect of Gamma Irradiation on Functional Properties:
The effect of gamma irradiation (0.0, and 2.0 KGys) on water and oil absorption capacity, b u lk dens ity,
emuls ion capacity and activity, foaming capacity and foaming s ta b ility of groundnut flour for both cultivars
are shown in table 4. The results  indicate that irradiation had no apparent effect on water absorption capacity.
These findings  were in accordance with that report ed by Zayas  (1997) who found that the water holding
capacity was  not affected by gamma irradiation. W ith regards  of the results  of oil absorption capacity, it  is
clear that, no change was  observed in oil absorption capacity of Madani cultivar, however, s ignificant increase
for Sodari was  observed, These results  are in agreement with previous  finding of Abu et a l .  (2005) who
reported that at low dose irradiation (2 kGy), the oil absorption capacity of cow pea flour was  not affected.
However, an increase in oil absoption capacity was  observed at higher doses  (10 and 50 KGys), t h is  ma y  be
due to exposure non-polar protein s ites . Moreover, the results  show that, the bulk dens ity of ground nut flour
of both cultivars  was  not affected s ignificantly by gamma irradiation. However, It was  observed that gamma
irradiation decreases  s ignificantly (P 0.05) the emuls ion  c a p a city of Sodari cultivar, while s ignificant increase
Aust. J. Basic & Appl. Sci., 3(3): 2856-2860, 2009
2859
was  observed for Mada ni cultivar. On the other hand no s ignificant change was  observed in emuls ion activity
for both cultivars . It was  reported that irradiation of cow pea at 2.0 KGys  caused decrease in emuls ion capacity
(Abu et al.., 2005). The changes  in emuls ion propert ie s  may be attributed to protein aggregation as  well as
surface hydrophobicity and change the characteris tics , which affe c t emuls ifying properties  in different ways
(Cheftel et al., 1985). The results  also indicate that gamma irradiation h a d  n o apparent affect on the emulation
s tability of ground nut flour of both cultivars . This  result is  in agreement of that  reported by Abu et al. (2005)
who concluded that at low dose of gamma irradiation emuls ifying properties  were not affected. 
Table 3: Effect of gamma irradiation on oil quality attributes of groundnut seeds   
T reated Dose IV AV PV SV RI RV
cultivars (Kgys) (%) (%) (%) (%)
Sodari 0.0 12.73 2.05 11.33 845.73 1.470 1.46a b d a b b
2.0 12.63 4.67 23.00 820.63 1.470 1.45a a a a b b
Madani 0.0 2.90 2.24 12.67 868.90 1.469 1.51a b c a  a a
2.0 09.60 2.24 19.33 867.60 1.469 1.52b b b a a  a
SEM 0.20 0.09 0.35 23.97 0.0001 0.001-
IV= iodine value         AV= acid value        PV= peroxide value        SV= Sapo n i fication  value  RI= Refractive index    RV=
Relative viscosity
Means in the same column with different letter (s) are significantly different (P 0.05) according to Least Significant T est (LSD)
SEM: standard error of means. 
Table 4: Effect of gamma irradiation on functional properties of groundnut seeds   
T reated Dose W AC OAC EC EA ES FC BD
cultivars (Kgys) (ml/100g) (ml/100g) (%) (Mg/g) (%) (%) (g/m )
Sodari 0.0 180.73 320.470 0.35 154.73 47.360 05.35 08.00b c a a a b b
2.0 180.73 320.470 0.35 150.73 47.360 12.35 12.00b c a b a a a
0.35 138.73Madani 0.0 280.90 340.469 a d 47.360 12.35 07.00
a b a a c
2.0 280.60 340.469 0.35 148.73 47.360 12.35 08.00a b a c  a a b
SEM 0.001 0.001 0.00 0.39 0.00 0.75 0.002-
W AC = water absorption capacity    OAC = oil absorption capacity    EC = emulsion capacity           EA=  em u l s i o n  act i v i t y       ES=
emulsion stability    FC= foam capacity     BD=  bulk density            
Means in the same column with different letter (s) are significantly different (P 0.05) according to Least Significant T est (LSD)
SEM: standard error of means.
Conclusion:
The irradia tion applied to groundnut seeds  indicated no subs tantial change in proximate and minerals
compos ition; however, for the quality attributes  of groundnut oil, gamma irradiation caused s ignificant decrease
(P 0.05) in iodine value and s ignificant increase in acid and peroxide value s  wit h  exception of the acid value
of Madani cultivar. W hile saponification value, refractive index and viscos ity not affe c t ed s ignificantly. W ater
holding capacity, bulk dens ity, emuls ion activity and emuls ion capacity of ground n u t  flour were not
s ignificantly affected by gamma irradiation.
REFERENCES  
A b u , J .O., M. Klaus ., G.D. Kwaku, G. Duodu and  M. Amanda, 2005 Functional properties  of co wp e a
(Vigna unguiculata  L. W alp) flours  and pas tes  as  affected by ã-irradiation. Food chemis try, 93: 103-111.
Adegoke, G.O., K.O. Falade and O.C. Babalola, 2004. Control of lipid oxida t io n  a n d  fu n g al spoilage of
roas ted peanut (Arachis hypogea) us ing the spice a  fra mo u n  d e n ielli, Food, Agriculture and Environment, 2:
128-131.
Alb a s h ir,  M ., 2004. Effect of gamma irradiation on fungal load, chemical and sensory characteris tics  of
walnut. Stored Products  Research, 40: 355-362.
AOAC., 1990. Official method of analys is  of the Ass o c ia t io n of Official Analytical Chemis ts , 15  ed.th
Association of Official Analytical Chemis ts . W ashington, D.C.
AOCS., 1972. Official and Tentative Methods , Amer. Oil. Chem. Soc., Champaign, USA.
Beuchat, L.B., 1977. Functional an d  e le c t rophoretic characteris tics  of succinylated peanut flour protein. J.
Agric. Food. Chem., 25: 258-261.
Cheftel, J.C., J.L. Cuq and D Lorient, 1985. Fo o d  c h e mis try (2nd ed.), Marcel Dekker, New York, pp.
245–369.
Coffman, C.W . and V.V. Gracia, 1977. Functional p ro p e rties  and amino acid content of a protein isolate
from mung bean flour. J. Food Technol. 12: 473.
Aust. J. Basic & Appl. Sci., 3(3): 2856-2860, 2009
2860
Gomez, K.A. and A.A, Gomez, 1964. S t a t is tical procedures  for agricultural research, second edition, John
and wily Sons , Lnc,New York.
Ishag, H.M., 1986. Groundnut Production and Research Problems in the Sudan. Research on grain legumes
in Eas tern and Central Africa, Addis  Ababa, Ethiopia, pp: 65-69. ICRISAT.
Ishag, H.M., M .A . A li and. A.B. Ahmadi, 1980. Groundnut production and research problems in the
Sudan. International workshop on groundnuts , Patancheru, India,  pp: 282-284. ICRISAT.
Jood, S. and  A.C. Ka p o o r, 1993. Protein and uric acid contents  of cereal grains  as  affected by insect
infes tation. Food Chemis try, 46: 143–146.
Modgil, R., 2000. Mineral content of in s e c t  in fe s ted s tored legumes  treated with edible oils . Nahrung, 44:
415-422.
Ogbadu, G.H., 1980. Influence of Gamma Irradiation of aflatoxin B1 production by Aspergillu s  fla v u s
growing on some Nigerian meals . Science of Microbes , 27: 19-26.
Pearson, D., 1981. Ge n e ra l methods  in chemical analys is  of foods  (pp. 11). Edinburgh/London/New York:
Churchill Livings tone.
Rady, A.H., S.M. Abdel Hady, F.M. Elnashabi, E.A  Afifi and E.M. Salam, 2002. Influence of Gamma
rays  and Microwave h e a t in g on the Quality of Olive fruits  and their virgin oil. Isotope and Rad. Res ., 34: 369-
380.
Seda, H.A, G.S. Moram, A .A . M a h mo u d  and H.F. Elneily, 2001. Chemical and biological changes  of
peanut kernels  by Gamma Radiation. Annals  of Agricultural Science, 46: 233-251.  
Siddhuraju, D., O. Osoniyi, H.P.S. Makka r and K. Becker, 2002. The effect of Soaking and Ionizing
Radiation on va rio u s  anti-nutritional factors  of seeds  from different species  of an unconventional legume
sesvaria  and common legume, green gram (Vigna radiate). Food Chemis try, 79: 273
W HO., 1987. Food Irradiation. In: Point of Fact. No. 40. Geneva, Switzerlan
Ya s u ma t su, K.K., S. Sawada, M. Moritaka, J. Misaki, T. Toda, W ada and K. Ishii, 1972. W hipping a n d
emuls ifying properties  of soybean products . Agricultural and Biological Chemis try, 36: 719.
Zayas , J.F., 1997. Functionality of proteins  in food. (p.81) New York: Springer.
Zeb, A. and T. Ahmad, 2004 The High Dose Irra diation Affect the Quality Parameters  of Edible Oils .
Pakis tan Journal of Biological Sciences , 7: 943-946.


Effect of Gamma Irradiation on the Physico-chemical Characterstics of Groundnut (Arachis Hypogaea)

http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=D158F1839F68F3A19950BB2A8571ADD7?doi=10.1.1.1070.3945&rep=rep1&type=pdf

Effect of Gamma Irradiation on the Physico-chemical Characterstics of Groundnut (Arachis Hypogaea)

Abstract

Similar works

Full text

Available Versions

CiteSeerX