African Journal of Biotechnology Vol. 7 (19), pp. 3502-3504, 6 October, 2008
Available online at http://www.academicjournals.org/AJB
ISSN 1684–5315 © 2008 Academic Journals

Short Communication

Amino acid profile of two non-conventional leafy
vegetables, Sesamum indicum and Balanites
aegyptiaca
D. Kubmarawa*, I. F. H. Andenyang and A. M. Magomya
Department of Chemistry, Federal University of Technology, P. M. B. 2076, Yola, Nigeria.
Accepted 31 July, 2008

The leaves of Sesamum indicum and Balanites aegyptiaca are popularly consumed in Adamawa Stateof Nigeria largely by the rural communities. They were analyzed to determine proximate nutrient
content, amino acid composition and antinutritional factors. Data obtained for proximate composition
showed protein content of 18.59 and 15.86% for S. indicum and B. Aegyptiaca, respectively. These
values are high compared to those for some common Nigerian vegetables. Leaves of both plants hadhigh percentages of crude fibre (27.58 and 30.75%). Carbohydrates, lipid, moisture and ash contents
were within the range expected for dry leafy vegetable. Seventeen (17) amino acids were found invarying proportions in the protein of both vegetables. The anti-nutritional factors analyzed; tannins,oxalates and phytates, in the vegetables were lower than the range of values reported for mostvegetables.
Key words: Sesamum indicum, Balanites aegyptiaca, amino acid, nutrients, antinutrients, vegetables.
INTRODUCTION
Sesamum indicum is an annual plant belonging to thePediliaceae family. It is one of the world’s most importantoil crops grown in developing countries by small holders(FAO, 1993). Its oil, seed and leaves have been ascribedseveral medicinal and other desirable properties andyoung shoots are used as vegetables in soups (Bokhariand Ahmed, 1999). S. indicum grows flamboyantly withgood seedling property. It is grown as leafy vegetable infamily home gardens and contributes to house hold foodsecurity. It also serves as a source of income to families(Rubahaiyo, 1994).
Balanites aegyptiaca, commonly known as desert date,is a small evergreen tree reaching a height of 6 – 12 m. It
belongs to the Zygophyllacea family and produces fruits,
which are edible. Fresh new shoots, which are always
growing during the dry season, are commonly used asanimal forage but in periods of food shortage, people cut
the newly growing succulent shoots with the leaves, cookand eat them. The plant is commonly found wild in Borno
and Adamawa States of Nigeria.

*Corresponding author. Email: dkubmarawa@yahoo.com

Green leafy vegetables constitute an indispensable
constituent of the human diet in Africa generally andWest Africa in particular (Oguntona, 1986). It has been
estimated that over 60 species of green leafy vegetables
are consumed in Nigeria alone (Okoli et al., 1985). In
Nigeria and other developing countries, as a result offood shortage and high cost of cultivated green leafy
vegetables, wild and semi-wild food resources are
frequently consumed as the dominant source of leafy
vegetables especially in the rural communities (Barminas
et al., 1998). These non-conventional leafy vegetableplay an important role in every day cooking especially inthe rural areas. In addition, the vegetables supply
calories and nutrient during dry season when there isshortage of cultivated green vegetable and other foodresources. Many of such plants have been identified butlack of data on their chemical composition has limited theprospect of their utilization (Baumer, 1995). S. indicumand B. aegyptiaca fall in the category of such plants. Bothare popular among certain communities in Adamawa
state of Nigeria. By learning more about their nutritional
and anti-nutritional composition, one can better assess
their importance in the well being of the communities that
consume them.
This work is designed to examine the leaves of S. indi-Kubmarawa et al.

Table 1. Proximate composition of the leaves of S. indicum andB. aegyptiaca (g/100 g, dry weight).

Parameter
Moisture
Ash content
Lipids (fats)
Crude fibre
Crude protein
Carbohydrate

S. indicum
7.83 ± 2.12
10.30 ± 1.08
1.66 ± 0.24
27.58 ± 0.50
18.59 ± 0.82
34.04 ± 0.43

B. aegyptiaca
13.11 ± 0.50
9.26 ± 0.47
2.90 ± 0.07
30.75 ± 1.83
15.86 ± 0.56
32.38 ± 0.10

Values are means ± SD for three (3) determinations.

cum and B. aegyptiaca for proximate nutrient content,amino acid composition, and anti-nutritional factors. The
report would provide necessary information on bothvegetables and provide basis for their wider utilization.
MATERIALS AND METHODS
Collection and treatment of samples
Leaves of S. indicum and B. aegyptiaca were sampled randomly
from farmlands in Yola, Adamawa State, Nigeria in the month of
September 2005. The leaves were plucked and air dried in a closed
room, that is, away from sunlight. They were then grounded intofine powder using pestle and mortar (stainless steel) and stored inscrew capped containers.

Proximate analysis
The samples were analyzed for proximate composition (moisture,crude fat, fibre, carbohydrate and protein). Moisture and lipid weredetermined by Cocks and Pede (1996) method. The method ofNielson (1994) was adopted for the determination of ash and crude
fibre. Determination of crude protein was by the micro-Kjedahl
procedure. The carbohydrate content was obtained by difference.
Amino acid analysis
The amino acid profile was determined using the method describedby Sparkman et al (1958). Each sample was dried to constantweight, defatted, hydrolyzed, evaporated and loaded into thetechno sequential multi-sample amino acid analyzer (TSM).
following the steps described below: 2 g of the dried sample wasweighed into extraction thimble and the fat extracted withchloroform : methanol (2:1) mixture using soxhlet extraction
apparatus (AOAC, 1990). Then, 1 g of the defatted sample wasweighed into glass ampoule. 7 ml of 6 N HCl were added andoxygen expelled by passing nitrogen into the ampoule. The glass
ampoule was sealed and placed in an oven preset at 1050C for 22h. The ampoule was allowed to cool before breaking open at the tipand the content filtered. The filterate was then evaporated todryness and the residue dissolved with 5 ml acetate buffer (pH 2.0)
and stored in plastic specimem bottles. 10 µl was dispensed into
the cartridge of the analyser which is designed to seperate andanalyse free, acidic, neutral and basic amino acids of thehydrolysate. The amount of each amino acid present in the sample
was calculated in g/100 g protein from the chromatogram produced.
Table 2.

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Table 2. Amino Acid composition of the leaves of S. indicumand B. aegyptiaca (g/100 g protein).

Amino acidS. indicum

B. aegyptiaca

LysineThreonine
Cysteine
ValineMethionine
IsoleucineLeucine
Tyrosine
Phenylalanine
Histidine
Arginine
Aspartic acid
SerineGlutamic acid
ProlineGlycine
Alanine

4.90
3.61
0.10
4.92
1.08
3.73
8.66
3.26
5.00
2.61
4.66
8.11
2.02
10.02
2.96
0.85
2.11

4.51
2.88
0.79
4.07
0.73
3.50
6.23
3.16
4.80
2.83
4.20
7.86
2.01
10.80
1.85
9.65
1.80

Determination of anti-nutrients
Tannin content was estimated using the vanillin-HCl method
modified by Price and Butler (1977). Oxalates were analyzed using
the method of Ukpabi and Ejidon (1999). The Reddy and Lovemethod (1999) was adopted for the estimation of phytates.

RESULTS AND DISCUSSION
The proximate composition of S. indicum and B.
aegyptiaca are given in Table 1. The results of the analysis showed high protein content for S. indicum (18.59%)
and B. aegyptiaca (15.86%). These values are higher
than those for some common vegetables such as
Amaranthus hybridus (4.6%) and Telferia occidentalis(4.3%) but lower than Cochorus olitoris (27.4%) asreported by Fafunso and Bassir (1977) and Ifon andBassir (1979). Crude fibre in the vegetables wererelatively high (27.58% and 30.75%) for S. Indicum andB. Aegyptiaca, respectively. This implies that in the diet,the two vegetables will perform the important role ofpromoting softer stools with increased frequency andregularity of elimination as is characteristic of fibre-richdiets (Okaka et al., 2000). Lipids, ash and carbohydratecontents of the samples were within the range expected
for dry leafy vegetables (Osagie and Offiong, 1998).
Seventeen amino acids were found in varying proportions in both vegetables. Glutamic acid had the highest
value for both vegetables, while the limiting amino acid in
both samples was cysteine. All the essential amino acids
were present in both vegetable.
A major factor limiting the wide use of many plants isthe ubiquitous occurrence in them a range of natural

3504

Afr. J. Biotechnol.

Table 3. Antinutritional content of S. indicum and B.
aegyptiaca (mg/100 g).

Antinutrient

S. indicum

B. aegyptiaca

Phytic acid

10.90 ± 0.68

2.97 ± 0.43

Tannins

4.80 ± 1.47

4.10 ± 0.14

Oxalates

56.5 ± 0.06

75.0 ± 0.08

compounds capable of eliciting deleterious effects in manand animals. These compounds known as antinutrientsare of different types and widely distributed in the animal
kingdom (Osagie and Offiong, 1998). The anti-nutritional
factors; tannins, oxalates and phytates were present invarying amounts in both vegetables (Table 3). Phytic acidhas been reported to reduce the bioavailability of traceelement and minerals (Apata and Ologhobo, 1989). The
phytate content of both S. indicum and B. aegyptiaca
were, however, below the range reported for most vegetables. Tannin content of S. indicum (4.8 mg/100 g) andB. aegyptiaca (4.10 mg/100 g) were low and therefore will
not cause the deleterious effects of tannins, which isreduction in digestibility of nutrients. Oxalates are considered anti-nutrients as well as toxins. They rendercalcium unavailable by binding the calcium ion to form
insoluble calcium oxalate complex. Oke (1969) has
shown that on a dry weight basis, some of the Nigerian
vegetables may be superior to milk as gross sources ofcalcium except that the calcium is not available due to thepresence of oxalic acid and is bound as insoluble calciumoxalate. High oxalate diet can increase the risk of renal
calcium absorption. Oxalate contents of S. indicum andB. aegyptiaca were, however, lower than those associated with renal problems (Marshal et al., 1967).
Conclusion
This study has revealed that the vegetables, S. indicumand B. Aegyptiaca, consumed in Adamawa State cancontribute useful amount of nutrients including aminoacids to human diet. Interestingly, the anti-nutritional
contents of both vegetables were low, much lower than isobtainable in most Nigerian vegetables. This implies that,the overall nutritional value of the vegetables will not beaffected. Indeed, these vegetables consumed largely by
the rural populace in Adamawa State are not inferior tothe conventional popular Nigerian vegetables. There isneed, however, to determine the vitamins and minerals
present in the vegetables. Understandably, nutrient loss
is of great concern during blanching and cooking ofvegetables, therefore there is need to study the effects ofcooking and processing procedures on nutrient availability of the vegetables. This will help to adequately
establish their importance in human nutrition and provide
basis for maximum utilization of the plants.

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