Vol.4, No.5B, 73-77 (2013) Agricultural Sciences
Physicochemical properties, vitamins, antioxidant
activities and amino acid composition of ginger
spiced maize snack ‘kokoro’ enriched with soy
flour (a Nigeria based snack)
Fasasi Olufunmilayo Sade*, Alokun Omot ayo Aderonke
Department of Food science and Technology, Federal University of Technology, Akure, Nigeria; *Corresponding Author:
Received 2013
Blends of white maize, ginger po wder (white and
yellow) and soy flour were prepared at the fol-
lowing ratio of white maize 97%: yellow ginger
3% (WM /YG); white maize 97%: white ginger 3%
(WM/WG); white maize 87%: soy bean 10%: yel-
low ginger 3% (WM/S/YG); white maize 87%: soy
bean 10%: white ginger 3% (WM/S/WG), white
maize 90%: soybean 10% (WM/S), white maize
100% (WM) control. As result revealed protein
content, energy value, ash contents of ginger
spiced ‘kokoro’ improved significantly with the
addition of ginger spice and or soy flour com-
pared with the control. The mineral composition
of ginger spiced ‘kokoro’, increased signifi-
cantly at p < 0.05 especially with WM/S. Addition
of ginger and or soy improves the vitamin A and
C content of ginger spiced ‘kokoro’, WM/S/YG
had the highest vitamin A. while WM/S/WG had
the highest Vitamin C content as compared with
the control (WM). Result revealed that WM/S/YG
displayed the highest DPPH radical scavenging
actives. Significant (p < 0.05) improvement was
observed in the amino acid content of the ginger
spiced ‘kokoro’. The addition of ginger powder
and or soy flour decreases the load at break (N),
compressed Extension at Break (mm), and the
energy at break (J) of th e ginger spic ed ‘kokoro’.
Keywords: Maize; Ginger Powder; Soy Flour;
Snacks are becoming popular most especially in the
urban cities due to the fact that most people now work
far away from their homes. The annual production of
maize in Nigeria is about 5.6 million tones [1]. It is pre-
pared and consumed in a multitude of ways which vary
from region to region or from one ethnic group to the
other. They are also used for the production of different
convenience snack foods which are eaten to prevent
hunger before the main meals or just (as relish) for the
fun of eating them. Maize are deficient in sulphur amino
acids such as lysine hence the need to compliment maize
with legumes such as groundnuts and soybeans which
are better sources of the sulphur amino acids [2];
Ameida-Dominguez et al,[3] reported an improved bal-
ance of amino acids in the products made from such
combination. Omueti and Morton [4] reported that snack
does not provide nutrients in adequate quantities needed
by the body, which is due to their composition or due to
the production process. Whatever might have been re-
sponsible for their poor nutritional content, it is neces-
sary to ensure that food consumed as main meal or snack
contain required nutrients in adequate amounts, this is
important because many people now work outside their
homes due to urbanization and are becoming more de-
pendent on snacks for the supply of part of their daily
nutritional requirements. It is therefore necessary to pro-
duce a highly acceptable snack with high nutritional
quality that could be useful in nutritional programmes to
combat malnutrition and nutrient deficiencies [5]. Ginger
(Zingiber officinale) is a spice believed to be indigenous
to South East Asia, from where it has spread to other
tropical regions of the world [6]. Other major producers
include India, Nigeria, Sierra Leone, Jamaica, China and
Haiti [7]. The extracts of ginger have multiple pharma-
cological effects, cardiotonic effects, gastro-intestinal
actions thermogenic, and antibiotic activities they are
also important as digestive stimulants [8]; Ginger is used
in food, beverages and confectionary [9]. Kokoro’ is a
popular local snack in South Western Nigeria made from
maize flour. It is widely accepted in Southwestern Nige-
Copyright © 2013 SciRes. Openly accessible at http://www.scirp.org/journal/as/
F. O. Sade, A. O. Aderonke / Agricultural Sciences 4 (2013) 73-77
ria; it is inexpensive compared to other snacks because of
its relatively low cost of production. It is widely accepted
among children and adults as a product that is consumed
on such a wide scale; it could be a convenient vehicle for
the desired nutritional and antioxidant properties. The
study aims at investigating the physicochemical proper-
ties, amino acid composition and antioxidant properties
of ‘kokoro’ substituted with soy flour and ginger spice.
2.1. Materials
Maize, ginger (white and yellow Zingiber officinale);
soybean (Glycine max); refined vegetable oil; onions and
salt used in this study were purchased, from a local mar-
ket in, Akure, Nigeria.
All chemical used were of analytical grades.
2.2. Methods
Production of Soybean flou r
Soybeans flour was produced using the method de-
scribed by [10], with little modification. Soy bean were
sorted cleaned manually. The clean seeds were soaked in
water for 2hrs and boiled in water at (100 ± 2)℃ for 20
mins. The blanched soybeans were dehulled manually and
drained. The decorticated seeds were oven (Model
DHG-9101.I SA) dried at (60 ± 5)℃ for 8 hrs. The
dried cotyledons were dry milled using an attrition mill.
Flour obtained was sieved using sieve of 150 µm.
Processing of ginger powder
Ginger roots used were cleaned, peeled, cut, wash and
dried at (60 ± 2) for 10 hrs in an oven (Model DHG-
9101.ISA). Dried ginger was milled and sieved using
150µm to obtain a powdery form.
Production of Ginger Spiced ‘Kokor’
A preliminary study on the traditional production of
‘kokoro’ was carried out in Imasayi Yewa South Local
government area of Ogun-State where ‘kokoro’ produc-
tion is their major source of income. The traditional
method of ‘kokoro’ production was used with a slight
modification. The maize grains were manually cleaned
and were cooked (boiled) till soft and dewatered. The
cooked grains were cooled over night and wet milled. 40
g of milled onions (the onions were peeled, cut and wet
milled) were added immediately after milling. 2 g of salt
was added to the dough (common salt was added to the
control ‘kokoro’ while rock salt was added to the re-
maining dough). Dough was gently mixed into a stainless
steel pot, depending on the ratios. Soybean flour and
ginger were added as appropriate the mixture was con-
tinuously mixed until stiff dough is formed. The mixed
dough was kneaded, rolled for 5 min on a chopping
board; cut out into pieces and rolled into ring shape on a
chopping board; the rings were deep fried in hot vegeta-
ble oil at (150 ± 2) for 10min. It was kept overnight to
cool and fried again the next day at (150 ± 2) for 3
min till a white crispy color was obtained. It was cooled
and packed into a sealed polyethylene bags and kept at 4
before use.
The formulations were prepared using the following
blend ratio.
Proximate composition of the ‘kokoro’ was deter-
mined as described by AOAC [11]. Carbohydrate was
calculated by difference. Energy was calculated using
Atwater factor. The Calcium, Sodium, Magnesium and
Potassium contents were determined by flame photome-
try [11]. The concentration of Iron was determined after
wet digestion with a mixture of perchloric and nitric acid
using Atomic Absorption Spectrophotometry (AAS, Model
SP9, pye Unicam, UK). Phosphorus was estimated col-
orimetrically by ammonium molybdate method. Vitamin
A (β – carotene) was determined using acetone – petro-
leum ether (40 - 60℃) in the ratio 1 : 3 as a solvent as
described by [11]. Ascorbic acid (Vitamin C) was deter-
mined by titration against 2, 6 – dichlorophenol indo-
phenols as described by [12]. Determination of the amino
acid profile consists of two steps: Hydrolysis of the pro-
tein to constituent’s amino acids and the quantitative
estimation of the amino acids in the hydrolysate,
using the Technicon Sequential Analyzer Union Carbide
Corp., New York, N.Y. (TSM). The DPPH radical scav-
enging activity of the samples was determined according
to the method of Mensor et al. [13]. The breaking strength
(load at break), hardness (energy at break) and toughness
(extension at break) of the ‘kokoro’ was measured using
Universal Testing Machine (model M500-50KN, Tes-
tometric, England) according to the method described by
2.3. Statistical Analysis
All determinations were performed in triplicate and
the results are expressed as means values ± standard de-
viations (SD). The data were subjected to statistical analysis
using statistical program package STATISTICA. The
one-way analysis of variance (ANOVA) followed by
Duncan multiple range test were employed and the dif-
ferences between individual means were deemed to be
significant at P < 0.05.
The proximate composition (dry matter basis) of gin-
ger spiced ‘kokoro’ is shown in Table 1 Moisture content
(%) of ginger spiced ‘kokoro’ varied significantly, values
fell within the recommended moisture content of snack
pellets 10 and 14% [15]. Low moisture content is desir-
able in such snacks, as high moisture content could result
in crispiness of the snack, and accelerate other biochemi-
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F. O. Sade, A. O. Aderonke / Agricultural Sciences 4 (2013) 73-77
Copyright © 2013 SciRes. http://www.scirp.org/journal/as/
cal changes such as oxidative rancidity. Addition of gin-
ger and or soy flour resulted in significant increase in-
crease in the crude fiber, crude fat and protein content of
‘kokoro’. The increase in the fat content might be attrib-
uted for the fact that soy flour is rich in oil. Values ob-
tained for the protein content were fairly comparable to
the recommended protein level of 18% - 20% [16]. Addi-
tion of soy resulted in significant increase in the calcu-
lated energy content of ‘kokoro’ this might be attributed
to the oil in the snack which is a good source of energy.
As indicated in Tab le 2 , Addition of soy and or ginger
powder resulted in significant increase in the Ca, Mg, P,
Na and K, of ‘kokoro’ The Na/K ratio in the body is im-
portant because it helps in controlling high blood pres-
sure Na/K ratio values compares favourably with the
recommended value of less than one [17]. Nieman et al.,
[18] considered a food source good if the Ca/P ratio is
above 1 and poor if the ratio is less than 0.5. The maize
snack ‘kokoro’ happen to be good food source (Ca/P ra-
tio ranged from 0.5 -1.5) for minerals used in bone for-
mation. The presence of soy flour and ginger increased
the vitamin C and A contents of ginger spiced ‘kokoro’ in
comparison with the control (Figures 1 and 2). The
Table 1. Proximate composition of ‘kokoro’ substituted with soy flour and ginger spice (% dry matter basis).
(%) ASH
WM 10.71 ± 0.01d 1.88 ± 0.00d 20.92 ± 0.01f1.04 ± 0.00f8.32 ± 0.00 f 57.13 ± 0.00a 1887 ± 0.00 d
WM/WG 12.19 ± 0.01b 1.74 ± 0.01e 27.01 ± 0.01d1.09e ± 0.00 10.05 ± 0.00e 47.92 ± 0.02c 1985 ± 0.33bc
WM/YG 11.04 ± 0.01c 2.14 ± 0.01b 23.05 ± 0.01e1.15 ± 0.01d10.96 ± 0.01d 51.65 ± 0.03b 1917 ± 0.33d
WM/S/WG 10.15 ± 0.01e 1.94 ± 0.01c 29.98 ± 0.01b1.23 ±0.01b 13.11 ± 0.03c 43.59 ± 0.04d 2000 ± 73.17bc
WM/S/YG 12.47 ± 0.01a 2.19 ± 0.00a 29.86 ± 0.01c1.25 ± 0.01a13.60 ± 0.00b 40.63 ± 0.02e 2027 ± 0.00 b
WM/S 9.25 ± 0.01f 1.36 ± 0.01f 31.72 ± 0.03a1.21 ± 0.00c15.91 ± 0.01a 40.54 ± 0.04e 2135 ± 0.88a
Values represent means of triplicates. Values in a column with same superscript are not significantly different at p 0.05. NOTE: WM = White Maize; WM/WG
= White Maize: White Ginger; WM/YG = White Maize: Yellow Ginger; WM/S/WG = White Maize: Soy bean: Yellow Ginger; WM/S/YG = White Maize: Soy
bean: Yellow Ginger; WM/S = White Maize: Soy bean.
Table 2. Mineral composition of ginger spiced ‘kokoro’.
Samples Ca
(mg/100 g) Mg
(mg/100 g) P
(mg/100 g) Na
(mg/100 g K
(mg/100 g) Na/K Ca/p
WM 352 191 272 293 380 0.8 1.3
WM/WG 410 205 277 298 605 0.5 1.5
WM/YG 438 297 318 345 412 0.8 1.4
WM/S/WG 309 299 625 1517 1882 0.8 0.5
WM/S/YG 492 394 811 1610 1904 0.8 0.6
WM/S 488 366 713 1500 1978 0.8 0.7
Values represent means of triplicates. KEYS: WM = White Maize; WM/WG = White Maize: White Ginger; WM/YG = White Maize: Yellow Ginger;
WM/S/WG = White Maize: Soy bean: Yellow Ginger; WM/S/YG = White Maize: Soy bean: Yellow Ginger; WM/S = White Maize: Soy bean.
Figure 1. Vitamin C content of Ginger spiced ‘kokoro’. Figure 2. Vitamin A content of Ginger spiced ‘kokoro’.
Openly accessible at
F. O. Sade, A. O. Aderonke / Agricultural Sciences 4 (2013) 73-77
presence of white ginger increases vitamin C signifi-
cantly while the presence of yellow ginger increases the
vitamin A content. Vitamin C provides a protective func-
tion against free radicals. Average daily intake level that
is sufficient to meet the nutritional requirement of ascor-
bic acid or recommended dietary allowances (RDA) for
adults (> 19 yr) are 90 mg/day for men and 75 mg/day
for women [19]. Ginger spiced ‘kokoro therefore could
not be referred to as a good source of vitamin C. The
presence of yellow ginger increases the vitamin A con-
tent of ginger spiced ‘kokoro. The obtained results on the
DPPH radical scavenging activities of ginger spiced
‘kokoro’ are shown in Figure 3. The extract of ginger
spiced ‘kokoro showed a significant effect in inhibiting
DPPH. Increase of 11% had been observed in DPPH
scavenging activities of WM/S/YG, when compared with
WM. The antioxidant activity of plant extracts containing
polyphenol components is due to their capacity to be
donors of hydrogen atoms or electrons and to capture the
free radicals.
DPPH analysis is one of the tests used to prove the
ability of the components of the ginger spiced ‘kokoro’
extract to act as donors of hydrogen atoms and to capture
free radicals.
The amino acid composition of ginger spiced ‘Kokoro
is shown on Table 3.
Leucine is the most predominant essential amino acid
in the ginger spiced ‘kokoro’. These observation are in
agreement with the observations made earlier by Aremu
et al., [20] and Olaofe, et al., [21], suggesting Leucine as
the most concentrated essential amino acid in Nigerian
plant foods. Glutamic is the most concentrated non –
essential amino acid. Total essential amino acid in the
ginger spiced ‘kokoro’ ranged from 18.40 to 29.57
g/100 g protein; the highest was observed in WM/S/YG.
This implies that yellow ginger (YG) has higher total
essential amino acid than the white ginger (WG). The
nutritive value of a protein depends primarily on the ca-
pacity to
Figure 3. DPPH radical scavenging activities of ginger spiced
satisfy the needs for nitrogen and essential amino acids
[21]. TSAA for the ginger spiced ‘kokoro’ is higher than
the 5.8 g/100 g crude protein recommended for infants
[22], which makes ginger spiced ‘kokoro’ an ideal snack
for infants.
The textural profile of ginger spiced ‘kokoro’ is shown
in Table 4. Texture is a very important quality character-
istic which makes a significant contribution to the overall
quality acceptance of food products.
Table 3. Amino acid composition of Ginger spiced ‘kokoro’.
Amino acid WM/S/WG
(g/100 g
(g/100 g
(g/100 g
Tyrosine 2.86 3.02 3.02
Methionine 0.68 0.89 1.12
Threonine 2.48 2.71 3.04
Valine 2.86 3.29 3.41
Phenylalanine 3.23 4.02 3.93
Isoleucine 2.06 2.95 2.89
Leucine 7.15 8.60 9.15
Lysine 3.13 3.16 3.24
Cystine 0.79 0.93 0.99
Total Ess. AA 25.24 29.57 18.40
Histidine 1.89 2.21 2.30
Arginne 3.54 3.88 3.97
Aspartic Acid 5.12 6.11 6.14
Serine 2.20 2.79 2.82
Glutamic Acid 6.59 7.50 8.18
Proline 2.85 3.36 3.36
Glycine 2.79 2.91 3.15
Alanine 3.00 3.19 3.38
Isoleucine 2.06 2.95 2.89
Total Non Ess. AA 30.04 34.9 36.19
Total (TEAA + TNEAA)55.28 64.47 54.59
TEAA/TNAA% 0.84 0.85 0.51
TEAA/TAA % 0.46 0.46 0.34
TSAA (Meth +Cys) 1.47 1.82 2.11
Ar EAA (Phe + Tyr) 6.09 7.04 6.95
Table 4. Textural profile of ginger spiced ‘kokoro’.
Samples Load at
Break (N)Compressed Extension
at Break (mm ) Energy at
break (J)
WM 8.11 5.12 0.04
WM/S/WG 2.60 3.0 0.01
WM/S/YG 5.09 2.8 0.01
WM/S 3.60 4.7 0.03
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F. O. Sade, A. O. Aderonke / Agricultural Sciences 4 (2013) 73-77
Copyright © 2013 SciRes. http://www.scirp.org/journal/as/
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