Amino Acid Composition of Kilishi - Nigerian (Beef Jerky) Meat
Emmanuel Ilesanmi Adeyeye*1, Olatunde Abass Oseni2,
Kayode Olugbenga Popoola1, Yusuff Ayinde Gbolagade3,
Abioye Rauf Olatoye1, Kolade Idowu1
1Department of Chemistry (Analytical Unit), Ekiti State University, PMB 5363,
Ado – Ekiti, Nigeria
2Department of Medical Biochemistry, College of Medicine, Ekiti State University, PMB 5363,
Ado – Ekiti, Nigeria
3Central Laboratory, Ekiti State University, PMB 5363, Ado – Ekiti, Nigeria
*Corresponding author: email@example.com, firstname.lastname@example.org
Keywords: Amino acid composition; Nigerian, Kilishi meat
Abstract. The article reports the amino acid composition of Nigerian beef jerky meat called Kilishi.
Kilishi is consumed dry, hence determination was on dry weight basis. Sample was purchased in
Ado-Ekiti, Nigeria. Amino acid values were highest for non-essential amino acid in Glu
(14.3 g100g-1) whereas from essential amino acid it was Lys (8.69 g100g-1). Other high value amino
acids were (in g100g-1): Asp (8.85), Leu (7.68), Arg (6.02), Ile (4.08), Trp (1.02), Cys (1.18) and His
(2.40). P-PER1,2,3 values were superior at values of 2.52 – 2.70. EAAI1 (soybean standard) was 1.23
and EAAI2 (egg standard) was 94.5 with corresponding BV of 91.3. Lys/Trp was very high at 8.55
and Met/Trp was 2.38. Values of TNEAA was 52.1 g100g-1 (57.7%) and TEAA was
38.2 g100g-1(42.3%). In the egg score comparison Ser (0.461) was the limiting amino acid (LAA)
with protein corrected digestibility value of 0.338; in provisional EAA scoring pattern, LAA was Val
(0.882) and corrected version was 0.742; in pre-school children requirement, LAA was Trp (0.927)
and corrected value of 0.780. Variation percentage values between the scores/corrected scores were
virtually 12.2% per parameter compared. Correlation values between each score standard/corrected
score values were significantly different at r=0.01 with values of 0.9997 – 0.99999. Estimates of amino
acid requirements at ages 10 – 12 years (mg kg-1 day-1) showed kilishi to be better than the standards
at 74.9% - 453%. Results showed that kiishi is protein-condensed.
Kilishi is a version of jerky meat that originated in Hausaland (in Nigeria). It is a derived form
of suya, made from deboned cow, sheep or goat meat. Each of the selected muscle is sliced into sheets
of one metre or less for easy drying. The dried sheets of meat are then collected and kept for the next
process . [Jerky is lean trimmed meat that has been cut into strips and dreid (dehydrated) to prevent
spoilage]. Normally, this drying includes the addition of salt to prevent bacteria growth before the
meat has finished the dehydrating process .
A paste made from peanuts, called labu, is diluted with enough water, spices, salt, ground
onions, and sometimes sweetners such as honey, to add sweetness. A more natural way to add
sweetness is by adding date palm. The dried “sheets’’ of meat are then immersed one by one in the
labu paste to coat them, and then left for hours before roasting to taste [3,4].
After roasting, the final moisture content ranged between 10 – 12%, which decreases during
storage at room temperature to 7%. When packaged in hemetically sealed low density plastic pack of
0.038mm thickness, kilishi remains appreciably stable at room temperature for a period of about one
Other ingredients or treatments to improve the quality of kilishi are: use of suya spice (suya
pepper); cloves of garlic; one teaspoon of cloves (kanafuru); piece of ginger; stock cube; dry cayenne
pepper seeds; the meat used for kilishi should be free from fat and should be gotten from the reddish
part of the beef. Each of these items give kilishi special characteristics such as aroma, e.t.c. .
Sustainable Food Production Submitted: 2019-12-11
ISSN: 2624-876X, Vol. 8, pp 1-16 Revised: 2020-04-24
doi:10.18052/www.scipress.com/SFP.8.1 Accepted: 2020-04-28
2020 SciPress Ltd, Switzerland Online: 2020-10-19
SciPress applies the CC-BY 4.0 license to works we publish: https://creativecommons.org/licenses/by/4.0/
The above gave some information on the preparation, food characteristics and ingredients that
improve the nutritional quality of kilishi. However, there is paucity of information on the amino acid
composition and the digestibility of kilishi. These are the major concern of this work and in addition
the nutritional importance of consuming kilishi will be discussed.
Materials and Methods
Collection of samples
Samples of packaged kilishi were purchased from a supermarket in Ado – Ekiti, Ekiti Sate,
Nigeria. The Kilishi samples were actually prepared for sale by Golden Datol Ent., Akure, Ondo
State, Nigeria. The kilishi sample was labelled to contain beef, onion, garlic, salt, honey, ginger,
maggi, groundnut, pepper.
The kilishi pack were further oven-dried, allowed to cool, blended and packaged in plastic
containers and kept in a cool place pending analysis.
Extraction and analysis
Extraction and instrumental analysis were carried out by following AOAC method  and
Danka et al. .
The dried pulverized sample was made to be free of water by ensuring constant weight for a
period of time in the laboratory. The sample of 10.0g was weighed into the 250ml conical flask
capacity. The sample was defatted by extracting the fat content of the sample with 30ml of petroleum
spirit three times with Soxhlet extractor that was equipped with thimble. The sample was hydrolyzed
three times for complete hydrolysis to be achieved for the totality of amino acids recovery.
The pulverized and defatted sample was soaked with 30ml of 1M potassium hydroxide
solution and was incubated for 48 hours at 1100C in hermetically closed borosilicate glass container.
After the alkaline hydrolysis, the hydrolysate was neutralized to get pH in the range of 2.5-5.0. The
solution was purified by cation-exchange solid-phase extraction. The amino acids in purified
solutions were derivatised with ethylchloroformate by the established mechanism:
+2HCl + CO2
R' = C2H5
Figure 1. Derivatization process of amino acid
The derivatising reagent was removed by scavenging with nitrogen. The derivatized amino
acid was made up to 1ml in a vial for gas chromatography analysis. The gas chromatographic
conditions for the amino acids analysis were as follows: GC: HP6890 powered with HP ChemStation
rev. AO9.01  software; injection temperature: split injection; split ratio: 20:1; carrier gas:
hydrogen; flow rate: 1.0ml min-1; inlet temperature: 2500C; column type: EZ; column dimensions:
10m x 0.2mm x 0.25µm; oven programme: initial @ 1100C, first ramp @ 270C min-1 to 3200C ;
second, constant for 5mins at 3200C; detector: PFPD; detector temperature: 3200C; hydrogen
pressure: 20psi; compressed air: 35 psi.
Some calculations were made from the analytical data results.
(i) Estimation of isoelectric point (pI): The estimation of isoelectric point (pI) for a mixture
of amino acids was carried out using the equation of the form :
2 SFP Volume 8
IPm = ∑ni = 1 Ii Pi Xi (1)
where IPm is the isoelectric point of the mixture of amino acids, IiPi is the isoelectric
point of the ith amino acid in the mixture and Xi is the mass or mole fraction of the ith
amino acid in the mixture.
(ii) Estimation of predicted protein efficiency ratio (P-PER): Computation of protein
efficiency ratio (C-PER or P-PER) was done using the equations suggested by Almeyer
et al. :
P-PER1 = -0.468 + 0.454 (Leu) - 0.105 (Tyr) (2)
P-PER2 = -0.684 + 0.456 (Leu) - 0.047 (Pro) (3)
P-PER3 = -1.816 + 0.435 x Met + 0.78 x Leu + 0.211
x His – 0.944 x Tyr (4)
(iii) Leucine/isoleucine ratio: The leucine/isoleucine ratio, their differences and their
percentage differences were calculated.
(iv) Determination of essential amino acid index (EAAI2): The method of EAAI calculation
was due to Oser  using the egg protein amino acids as the standard.
(v) Calculation of biological value (BV): Computation of biological value (BV) was
calculated following the equation of Oser :
Biological value = 1.09 (EAAI) – 11.73 (5)
(vi) Computation of Lys/Trp and Met/Trp: The ratios of Lys/Trp (L/T) and Met/Trp (M/T)
(vii) Computation of amino acid scores: The amino acid scores were computed using three
- Scores based on amino acid values compared with whole hen’s egg amino acid profile
- Scores based on essential amino acid scoring pattern .
- Scores based on essential amino acid suggested pattern of requirements for pre-school
(viii) Estimation of essential amino acid index (EAAI1): The essential amino acid index was
calculated by using the ratio of test protein to the reference protein for each eight essential
amino acids plus histidine in the equation 6 :
(ix) Estimates of amino acid requirements at different ages (mg kg-1day-1): These
estimates were based on the essential amino requirements in mg kg-1day-1 body weight of
10 - 12 years school boys . The proposed formula for this calculation could be any of
- Essential amino acid x 1000/100 x protein(g 100g-1) (7)
- Essential amino acid x 10 x appropriate corresponding protein (8)
(x) Other calculations: Other determinations such as total amino acid (TAA), total essential
amino acid (TEAA), total non-essential amino acid (TNEAA), total acidic amino acid
Essential amino =
etc. for all 8 essential
amino acids + His
Sustainable Food Production Vol. 8 3
(TAAA), total basic amino acid (TBAA), total essential aliphatic amino acid (TEAlAA),
e.t.c. and their percentages were made. Total sulphur amino acid (TSAA), percentage of
cystine in TSAA (% Cys in TSAA) were also calculated. The various amino acid groups
into classes I-VII  were also calculated.
Determination of Protein Digestibility
The in-vitro protein digestibility was determined by the modified method of Akeson and Stahmant
 and AOAC . The sample containing the exact amount of 100mg of protein was incubated with
1.5mg of pepsin in 15ml of 0.1M hydrochloric acid at a temperature of 38oC for 3 hours. The solution
was neutralized with 0.2M sodium hydroxide. Four mg (4 mg) of pancreas in 7.5ml phosphate buffer
of pH 8.0 was added with the addition of 1ml of toluene for the prevention of microbial growth and
the solution was incubated for another 24 hours at 38oC. The protein content in the solution after 24h
of digestion was taken as a measure of the digested product. Following the 24h incubation, the enzyme
was inactivated by the addition of 10ml of 10% trichloroacetic acid (TCA) to precipitate undigested
protein that was later filtered off. The volume of the filterate was made up to 100ml and centrifuged
at 5000 rpm for 30 minutes; the supernatant was collected for protein determination. Blank was
digested following the same procedure and employed 1g of each source of enzyme to make protein
measurement carried out effectively . The digestibility of the protein was calculated by the
ℎ x 100 (9)
Determination of Protein Digestibility-Corrected Amino Acid Score
To calculate for protein digestibility-corrected amino acid score for individual foods requires
some steps to be taken. These steps are enumerated as follows. Proximate composition must be
determined; protein can then be calculated by using a nitrogen-to-protein conversion factor of 6.25.
In amino acid profile, protein hydrolysate should be prepared and analysed for amino acid using
standard method. Amino acid scores would then be calculated (to give uncorrected amino acid
scores). Based on the determined protein digestibility, protein digestibility-corrected amino acid score
(PDCAAS) of the test food was then calculated by multiplying the amino acid score x true protein
digestibility (or each amino acid score might also be corrected using this similar approach as the case
may be). In this report, the score was expressed as a decimal, but it can be expressed in percentage
Data results in Tables 1, 5, 6 and 7 were subjected to statistical analyses of correlation
coefficient (rxy), regression coefficient (Rxy), coefficient of determination or variance (rxy2), the
coefficient of alienation (CA) and index of forecasting efficiency (IFE). Other calculations were grand
mean, standard deviation (SD) and coefficient of variation (CV%). The rxy value was converted to
critical Table value (rT) to see if significant differences existed among the various comparisons made
in the Tables enumerated above at r=0.01 .
Results and Discussion
Amino acids encountered in this work:
Lysine (Lys) [PubChem C6H14N202, CID: 5962]; Glutamic acid (Glu) [PubChem
C5H9NO4, CID: 33032]; Methionine (Met) [PubChem C5H11NO2S, CID: 6137]; Alanine (Ala)
[PubChem C3H7NO2, CID: 5950]; Arginine (Arg) [PubChem C6H14N4O2, CID: 6322]; Valine
(Val) [PubChem C5H11NO2, CID: 6287]; Leucine (Leu) [PubChem C6H13N02, CID: 6106];
Aspartic acid (Asp) [PubChem C4H7NO4, CID: 5960]; Threonine (Thr) [PubChem C4H9N03, CID:
6288]; Tryptophan (Trp) [PubChem C11H12N2O2, CID: 6305]; Isoleucine (Ile) [PubChem
C6H13NO2, CID: 791]; Phenylalanine (Phe) [PubChem C9H11NO2, CID: 6925665]; Histidine (His)
4 SFP Volume 8
[PubChem C6H9N3O2, CID: 6274]; Tyrosine (Tyr) [PubChem C9H11NO3, CID: 6057]; Cystine
(Cys) [PubChem C6H12N2O4S2, CID: 67678]; Serine (Ser) [PubChem C3H7NO3, CID: 5951];
Glycine (Gly) [PubChem C2H5NO2, CID: 750]; Proline (Pro) [PubChem C5H9NO2, CID: 145742].
PubChem is a database of chemical molecules and their activities against biological assays.
The system is maintained by the National Centre for Biotechnology Information (NCBI), a
component of the National Library of Medicine, which is part of the United States National Institute
of Health (NIH). Hence we can talk of PubChem Compound ID (CID).
The concentration of amino acids of Kilishi (dry weight) sample in g 100g-1 is shown in Table
1. In the amino acids (AAs) investigated, glutamic acid (Glu) was the most concentrated with a value
of 14.3 g 100g-1 protein; the next acidic amino acid (AAA), aspartic acid (Asp) was also high at
8.58 g 100g-1 (ranking as number three in AA concentration). The second most concentrated AA was
lysine (Lys) with a value of 8.69 g 100g-1, this is an essential amino acid (EAA). Other EAA of good
concentration were Val, Ile, Leu, Met, His and Trp whereas other nonessential amino acid (NEAA)
of good concentration were Gly, Ala, Arg and Cys. The Glu value in this report was lower than the
following literature values: heterosexual flesh of Neopetrolisthes maculatus (17.7 – 17.8 g 100g-1
protein) ; also the Asp level was lower than the flesh of the heterosexual N. maculatus with values
of 10.0 – 9.90g 100g-1 protein . The Glu and Asp levels in the present report were however higher
than those observed in the flesh of female West African fresh water crab (Sadananautes africanus
africanus) with Glu of 130.2 mg g-1 protein and Asp of 72.5 mg g-1 protein . Studies of Sinclair
et al. , Schweigert and Payne , Mahan and Shields  showed EAAs in g 100g-1: Lys in
beef (8.2), lamb (7.5) and pork (7.9), all lower than present report; present Leu value was 7.68 close
to their own values of beef (8.5), lamb (7.2) and pork (7.6); Ile was lower at 4.08 compared to their
values of beef (5.0), lamb (4.7) and pork (4.8). These EAA values were higher in the literature values
in [23, 24, 25] than the present values as shown: (present/literature in g 100g-1): Val, kilishi/beef
(4.41/5.6), kilishi/lamb (4.41/5.1), kilishi/pork (4.41/5.2); Thr, kilishi/beef (3.63/4.2), kilishi/lamb
(3.63/4.8), kilishi/pork (3.63/5.2); Met, kilishi/beef (2.42/2.2), kilishi/lamb (2.42/2.4), kilishi/pork
(2.42/2.6); Phe, kilishi/beef (3.91/4.1), kilishi/lamb (3.91/3.8), kilishi/pork (3.91/4.3); His,
kilishi/beef (2.40/2.8), kilishi/lamb (2.40/2.9), kilishi/pork (2.40/3.1); Trp, kilishi/beef (1.02/1.3),
kilishi/lamb (1.02/1.2), kilishi/pork (1.02/1.5). Reports of Beach et al.  showed the percentage
values of amino acids in beef, lamb and pork: Lys, beef (8.11), lamb (8.68), pork (8.65), all lower
than the present Lys (8.69) and His, beef (2.25), lamb (2.37), pork (2.16), all lower than the present
His (2.40). In general, Beach et al.  observed that muscle tissues of these different classes of
animals do not differ widely in their amino acid patterns which implies that the same amino acid
composition of muscle proteins is reported throughout the animal kingdom and indicates that, as far
as these amino acids are concerned, the protein of one muscle is as good as that of another in supplying
amino acids in the diet.
Values of the amino acids shown in Table 1 were subjected to a combined descriptive and
inferential statistics as shown in Table 2. The amino acid values were grouped into essential and non-
essential amino acids giving a set of nine members each. The mean values were close
(4.25 g 100g-1 EAA – 5.79 g 100g-1 NEAA) with corresponding standard deviation (SD) values of
2.48 – 3.81 and coefficient of variation (CV%) values of 58.4 – 65.9. Note that the total EAA value
was 38.2 g 100g-1 and the NEAA was 52.1 g 100g-1 protein. The mean, SD and CV% showed the
homogenous nature or otherwise of the EAA and NEAA of the kilishi sample. For the inferential
statistics, these values were low: correlation coefficient (rxy) (0.1549), variance (rxy2) (0.0240) and
regression coefficient (Rxy) (0.2381). The rxy was not significantly different since the critical value
of 0.798 at r=0.01 > rc of 0.1549. On the other hand the coefficient of alienation (CA) was high
at 0.9879 with correspondingly low index of forecasting efficiency (IFE) of 0.0121. The value of CA
showed that virtually no relationship existed between the kilishi EAA and NEAA since the error of
prediction of relationship was high at 98.79% whereas reduction of error of prediction of relationship
was just 1.21%.
Sustainable Food Production Vol. 8 5
In Table 3, we depicted the summary of the concentrations of essential, aromatic, non-
essential, neutral etc. of the amino acid levels in the sample in g 100g-1. The total AAs values of
90.3 g 100g-1 were lower than in the innards of heterosexuals of N. maculatus with values of
95.4 – 97.6 g 100g-1 ; value also lower than 96.6 – 97.1 g 100g-1 in the flesh of the heterosexual
N. maculatus  but higher than the total AAs in the flesh of S. africanus africanus (777.0 mg g-1
protein) . Columns in Table 3 included AAs class and other quality parameters. Total NEAA
(TNEAA) was 52.1 with corresponding percentage value of 57.7. Total EAA (TEAA) was 38.2 (with
His) and percentage value of 42.3 whereas values of TEAA without His was 35.8 and the
corresponding percentage value was 39.7.
The total aromatic amino acid (TArAA) was 10.4 g 100g-1 and the TEArAA was
7.32 g 100g-1 protein; this is within the range of ArAA suggested for ideal protein (68-118 mg g-1
protein) ; this makes kilishi to be a good source of ArAA and might also be qualified as a
supplement to foods of lower ArAA values. The present ArAA value of 10.4 g 100g-1 protein was
higher than in the flesh of N. maculatus where values of 7.72 – 9.67 g 100g-1 protein were reported
. The percentage ratio of TEAA to the TAA of the sample was 42.3; this is above 39% considered
adequate as ideal food for infants, 26% for children and 11% for adults . The TEAA/TAA in egg
is 50% . The total sulphur amino acid (TSAA) had a value of 3.59 g 100g-1 which is lower than
the TSAA recommended for infants (58 mg g-1 protein) .
The total SAA (TSAA) in the sample were made up of Met + Cys. Whereas the TSAA was
3.59 g 100g-1 protein, the percentage of Cys/TSAA value was 32.8 which is close to both innards
(26.7 – 33.0) and meat of N. maculatus at 31.9 – 33.1 [27, 13]. The present %Cys/TSAA (32.8) had
close relationships with other animal protein amino acids: 27.3 – 32.8% in S. africanus africanus
, 36.3% in Macrotermes bellicosus ; 25.6% in Zonocerus variegatus ; 35.5 in
Archachatina marginata marginata, 38.8% in A. archatina and 21.0% in Limicolaria sp. (the last
three are land snails consumed in Nigeria . The percentage of Cys in TSAA in the diet of rat chick
and pig is 50%  but the standard value is unknown to man . All the examples above came
from animal sources. It is noted however that vegetable protein (e.g. coconut endosperm) has a
percentage Cys/TSAA of 62.8% . Also reported was the high percentage of Cys/TSAA in
Anacardium occidentale with a value of 50.51% . From these literature values compared with the
present result, it is obvious that kilishi AAs behaved like typical animal in their %Cys/TSAA ratios.
The presence of cystine and cysteine in the diet reduces the needs for Met and since all the sulphur
in the diet is derived from these three AAs, the sulphur content is sometimes used as an approximate
assessment of the adequacy of protein . In the present result, the values for Met and Cys were
(g 100g-1 protein) 2.42 and 1.18 respectively.
The predicted protein efficiency ratio (P-PER) was calculated in three forms – P-PER 1, 2 and
3. The in-vivo P-PER is of the order of 2.2 . The P-PER values as calculated were:
P-PER1 = 2.70, P-PER2 = 2.62 and P-PER3 = 2.56 respectively. Although these three P-PER values
were each higher than the in-vivo value, all were lower than the following literature values:
N. maculatus meat where values of P-PER1 were 3.39 – 3.69 and P-PER2 were 3.82 – 4.14  and
also lower than the report for the innards of N. maculatus heterosexuals with values of P-PER1
(2.83 – 3.01) and P-PER2 (2.89 – 2.96) . According to Friedman’s  classification, the PER is
poor (< 1.5), moderate (1.5 – 2.0) and superior (> 2.0). On this classification, P-PERs 1, 2, 3 were all
in the group of superior category. Other literature P-PER values are: meat of female S. africanus
africanus, P-PER1 was 3.1 ; in Callinectes latimanus (a lagoon crab), P-PER1 was 1.21 and P-
PER2 was 1.39 . The present P-PER values indicated that kilishi meat might be a more
physiologically utilized protein source. In general, it has been discovered that the better the protein,
the lower the level in the diet that is required to produce the highest protein efficiency ratio. This
emphasizes a clear reflection of the importance of the proper nutritive balance of all amino acids to
produce optimum metabolic efficiency. More in Table 3, Leu/Ile ratio was 1.88, Leu – Ile (difference)
was 3.59 g 100g-1, %Leu – Ile/Leu was 46.8. In the meat of N. maculatus Leu/Ile ratio had values of
1.60 – 1.63 , in meat of S. africanus africanus, the ratio was 1.60  and the innards of N.
maculatus heterosexual the ratios were 1.54 – 1.91 with difference levels of 2.87 – 3.97 g 100g-1
6 SFP Volume 8
protein and % (Leu – Ile)/Leu values of 35.1 – 47.7 . From literature, the most ideal Leu/Ile is
2.36 . The value of 1.88 was low to 2.36, hence we might not experience concentration
antagonism in the sample when consumed as protein source in food. It has been suggested that an
amino acid imbalance from excess Leu might be a factor in the development of pellagra . A high
Leu imbalance in the diet impairs the metabolism of Trp and niacin, and is responsible for the niacin
deficiency in sorghum eaters . Experiments in dogs have shown that animals fed sorghum proteins
with less than 11g 100g-1 Leu did not suffer from nicotinic acid deficiency . The present Leu
value of 7.68 g 100g-1 protein was much less than 11 g 100g-1 protein and therefore considered safe
and could be beneficially exploited to prevent pellagra in endemic areas .
The essential amino acid index (EAAI) calculated were reported in two different forms of
EAAI1 and EAAI2. In the EAAI1, the value was 1.23. The EAAI1 under this mode has soybean as its
standard for comparison. The value of EAAI in defatted soybean flour is 1.26  and that for whole
hen’s egg is 1.55. In the amino acid composition of two fancy meats (liver and heart) of African giant
pouch rat (Cricetomys gambianus), the EAAI ranged from 1.20 – 1.31 . It should be noted that
the absence of Trp in EAAI calculation of this mode may bear no significance in the EAAI; for
example EAAI without Trp in soy flour remained 1.26 whilst it reduced to 1.54 in the whole hen’s
egg, i.e. a reduction of 0.01 or 0.645%. For the EAAI2, value was 94.5 with its corresponding
biological value (BV) of 91.3 depicting the quality of the kilishi protein. In comparison, some
literature values of EAAI and BV are as follows : milk, cow (whole, nonfat, evaporated or dry),
EAAI (88) and BV (84, predicted; 90, observed); human, EAAI (87) and BV (83); eggs, chicken
(whole, raw or dried, EAAI (100), BV (97, predicted; 96, observed); whites (raw or dried), EAAI
(95), BV (92, predicted; 93, observed); yolks (raw or dried, EAAI (93), BV (89, predicted); shellfish
(shrimp, including prawns, raw or canned), EAAI (67), BV (61, predicted); also 86.9 – 89.9 (EAAI)
and 83.0 – 86.3 (BV) in meat of N. maculatus  and 88.7 – 89.2 (EAAI) and 85.0 – 85.5 (BV) in
innards of N. maculatus . These literature results show the quality position of kilishi protein.
EAAI is useful as a rapid tool in the evaluation of food formulation for protein quality. The isoelectric
point, pI, was 5.63 showing the sample to be in the acidic medium of the pH range. The pI calculation
from amino acids would assist in the quick production of certain protein isolate of an organic product
without evaluating the protein solubilty before getting at the pI.
Table 3 also contained the Lys/Trp (L/T), Met/Trp (M/T) and Phe/Tyr ratios of the sample.
According to Albanese , in infants protein requirements, a growth pattern of amino acid
requirements was obtained by assigning value of unity to the Trp need. Similar calculation of the
amino acid content of mammalian tissue showed that there exists good agreement of growth needs
and tissue amino acid patterns. This agreement is said to be good for the L/T and M/T ratios of muscle
proteins which constitute approximately 75% of the infant body proteins. The present result had L/T
value of 8.55 and M/T value of 2.38. The L/T value was much more than those of innards of N.
maculatus as 3.00 – 5.01 and meat as 3.31 – 4.27 and also higher than M/T values as: innards,
1.78 – 3.50 and meat, 1.97 – 2.64 [21, 27].
Mammalian tissue patterns have the following values: L/T: muscle (6.3), viscera (5.3), plasma
proteins (6.2). M/T: muscle (2.5), viscera (2.0), plasma proteins (1.1) . The available evidence
indicates that the utilization of dietary proteins increases as their Lys and Trp approaches that of
muscle tissues. In the present study, the kilishi protein L/T value was 8.55 and it is 26.3% greater
than the muscle standard of 6.3 L/T, it is also much greater than 5.3 (viscera) and 6.2 (plasma)
proteins. Also the M/T value of the present work was 2.38 which is slightly lower than the muscle
standard M/T value of 2.5 but higher than 2.0 (viscera), 1.1 (plasma) proteins. The L/T and M/T
values were better than our observation for N. maculatus innards and meat [21, 27]. The mean
minimum Phe requirement estimate in the presence of an excess of Tyr is 9.1 mg kg-1 day-1. Hence
Tyr can spare 78% of the dietary Phe need. Also the optimal proportions of dietary Phe and Tyr have
been shown to be 60 : 40 respectively . The Phe/Tyr in this result was low as shown in Table 3
which did not meet the optimal proportion of dietary Phe and Tyr of 60: 40 respectively.
In Table 4 we have the amino acid groups divided into classes . The concentration trend
of the classes follows as shown in g 100g-1 protien: class I (27.3) > class IV (22.9) > class V (17.1) >
Sustainable Food Production Vol. 8 7
class VI (10.4) > class II (7.27) > class VII (4.23) > class III (3.59). In the innards of N. maculatus
the trend changed between classes VII and III as shown: class I > class IV > class V > class VI > class
II > class III > class VII ; this was also the trend in the meat of N. maculatus . Further
observation would show that the percentage were close to their individual values wih very slight
differences; examples were: value (percentage): class I, 27.3 (30.2); class II, 7.27 (8.04); class III,
3.59 (3.98); class IV, 22.9 (25.3); class V, 17.1 (18.9); class VI, 10.4 (11.5); class VII, 4.23 (4.69).
In Table 5, we presented the total amino acid scores based on whole hen’s egg amino acids
profile and the Protein Digestibility Corrected Amino Acid Score (PDCAAS). Under whole hen’s
egg score comparison, the following amino acids had scores of 1.00 or > 1.00: Lys, His, Gly, Pro,
Ala and Glu. Under PDCAAS comparison, values > 1.00 were recorded only in Lys, Gly and Glu;
this is 50% of such values observed in the egg score comparison. Ser was the limiting amino acid
(LAA) in both comparisons with values of 0.461 (on egg score) and 0.388 (on PDCAAS comparison).
Ser was also limiting with values of 0.511 (male) and 0.487 (female) in the innards of N. maculatus
and in meat of N. maculatus Ser values of 0.513 (male) and 0.516 (female), all on egg score
comparisons [21, 27]. To correct the present LAA scores to expected normal level in order to fulfil
the day’s needs for all the amino acids in kilishi sample, 100/46.1 and (or) 100/38.8; i.e. 2.17 and (or)
2.58 times as much kilishi protein would have to be consumed (eaten) when it serves as the sole
protein source in the diet as the case may be. The descriptive statistics in Table 5 showed that the
CV% ranged between 11.9 – 12.3. However, in this CV% values, out of 19 values reported, 15/19 or
78.9% had values of 12.2%; 2/19 or 10.5% had values of 12.3; 1/19 was for 12.1 and 11.9 in each
case giving a value of 5.26%. Generally speaking, one could reasonably conclude that egg score and
PDCAAS comparison had variations of 12.2%. In Table 6, we have EAA scores of kilishi based on
FAO/WHO  standards. Also there are the PDCAAS scores. For the FAO/WHO  scores, these
acids had scores > 1.00 : Lys, Met + Cys, Ile, Leu, Phe + Tyr, Trp and total EAA whereas in PDCAAS,
only Lys and total EAA had score values > 1.00. Val was the LAA in both comparison scores with
values of 0.882 and 0.742 respectively for provisional EAA scores and the PDCAAS. Correction
values would therefore be 100/88.2 or 1.13 x protein value and 100/74.2 or 1.35 x protein value for
full protein availability for body metabolism. In the CV%, 6/9 or 66.7% had values of 12.2%; 1/9 or
11.1% each for CV% 12.0, 12.1 and 12.3. In Table 7, we have depicted the EAA scores of kilishi
based on requirements or pre-school child (2 – 5 y). In the pre-school requirement score comparison
only Trp had score < 1.00 and hence LAA with a value of 0.927. Correction value here was 1.08 x
protein of kilishi. For PDCAAS, score values > 1.00 were in Lys, Met + Cys, Val, Ile, His and total
EAA. Also here Trp was the LAA with a value of 0.780, hence correction was 1.28 x kilishi protein
to get balanced protein source. Here, among the CV% values 6/10 (60.0%) were 12.2%; 3/10 (30.0%)
were with 12.3 and 1/10 or 10.0% was for 12.1%. Protein Digestibility Corrected Amino Acid Score
(PDCAAS) is a method of evaluating the protein quality, with a maximum possible score of 1.0. Most
animal meats like beef have a score of approximately 0.9, compared to values of 0.5 – 0.7 for most
plant foods .
The results of the scores from the egg/PDCAAS, provisional scoring pattern/PDCAAS and
pre-school child requirement/PDCAAS from Tables 5, 6, 7 were subjected to statistical analyses as
depicted in Table 8. In all the comparisons, all rxy values were high and positively significant. These
values were also high: rxy2, Rxy and IFE. Since all the IFE values were high at 0.9925 – 0.9962, it
meant that the quality criteria as depicted in the various scores from the standard score comparisons
and the PDCAAS values could be used to ascertain the kilishi quality at virtually similar levels.
In Table 9, we have estimates of amino acid requirements at ages 10 – 12 years in
mg kg-1 day-1 at the body weight of 30 kg. The protein of the kilishi sample had values greater than
the estimates in all the amino acids to the tune of between 74.9 – 453%. Among the four principal
limiting amino acids of Lys (first), Met + Cys (second), Thr (third) and Trp (fourth), the percentage
kilishi protein excess values were: Lys (211%), Met + Cys (185%), Thr (123%) and Trp (448%).
The various amino acids have different types of functions in the human body, phenylalanine,
a precursor for neurotransmitters which helps in the production of other amino acids and their
functioning. Valine helps in stimulating muscle growth, regeneration and it produces energy.
8 SFP Volume 8
Threonine is a principal component of structural proteins such as collagen and elastin which are
present in skin and connective tissues, helps in fat metabolism and immune function. Tryptophan is
a precursor to serotonin, a neurotransmitter that helps in appetite, sleep and mood regulation.
Methionine plays a major role in metabolism, detoxification, helps in tissue growth and in the
absorption of minerals such as zinc and selenium needed by the body. Leucine helps in regulating
blood sugar levels, enhances wound healing and stimulates growth hormones. Isoleucine helps in
muscle metabolism, immune function, haemoglobin production and energy regulation. Branched-
chain amino acids are Val, Leu and Ile. Lysine helps in protein synthesis, calcium absorption, immune
function, energy production, hormone production and in collagen production. Histidine, a
neurotransmitter helps maintaining the protective barrier called myelin sheath that surrounds the
nerve cells, helps in digestion, immune response, sleep – wake cycles and sexual functions .
Kilishi (Nigerian Beef Jerky) meat will serve as a good source of animal protein as well as
high quality amino acids. The crude protein value was 64.4g 100g-1. In amino acid quality parameters,
P-PER was in the superior group of value (> 2.0), both EAAI, BV and protein digestibility were high;
both Lys/Trp and Met/Trp were high. Scores at standard forms and PDCAAS were highly comparable
with slight variation of mostly 12.2%. Estimates of amino acid requirements at ages 10 – 12 years
(mg kg-1 day-1) in kilishi were all higher than the standards by a range of 74.9 – 453%. Based on the
above, kilishi will serve as a healthy snack with a lot of health benefits; it is protein-filled and retains
its nutritious value despite being dried.
Table 1. Amino acid profile (g 100g-1 protein) of Nigerian meat jerky (kilishi)
Amino acid CID† Kilishi
Aspartic acid (Asp)
Glutamic acid (Glu)
*Essential amino acid. Determination were done in duplicate and dry weight. †CID = Compound ID.
Sustainable Food Production Vol. 8 9
Table 2. Statistical analysis of the data from Table 1 pertaining to the amino acid profile of
essential and non-essential amino acid of kilishi
Total amino acid value
Standard deviation (SD)
Coefficient of variation (CV%)
Correlation coefficient (rxy)
Regression coefficient (Rxy)
Coefficient of alienation (CA)
Index of forecasting efficiency (IFE)
Results not significantly different at n – 2 and r= 0.01 (critical value = 0.798).
(NOTE: n – 2 = 9 – 2 = 7.)
Table 3. Composition in terms of different classes of amino acids in kilishi sample
(g 100g-1 protein)
Total amino acid (TAA)
Total non-essential acid (TNEAA)
Total essential amino acid (TEAA)
Total aliphatic amino acid (TAIAA) (CLASS I)
Total essential aliphatic amino acid (TEAIAA)
Total aromatic amino acid (TArAA) (CLASS VI)
Total essential aromatic amino acid (TEArAA)
Total acidic amino acid (TAAA) (CLASS IV)
Total basic amino acid (TBAA) (CLASS V)
Total neutral amino acid (TNAA)
Total hydroxyl amino acid (THAA) (CLASS II)
Cyclic amino acid (Pro) (CAA) (CLASS VII)
Total sulphur amino acids (TSAA) (CLASS III)
10 SFP Volume 8
% Cys in TSAA
% (Leu- Ile)/Leu
% (Leu- Ile)/total amino acid profile
P-PER1,i.e. -0.468+0.454 (Leu)-0.105 (Tyr)
P-PER2, i.e. -0.684+0.456 (Leu)- 0.047 (Pro)
, i.e. -1.816+0.435 x Met + 0.78 x Leu + 0.211 x His –
0.944 x Tyr
Calculated isoelectric point (pI)
Essential amino acid index: EAAI1
Biological value (BV)
Lys/Trp or L/T
Met/Trp or M/T
Table 4. Amino acid groups of kilishi
Value in g 100 g-1
I. [with aliphatic side chains (hydrogen and
carbon)= Gly, Ala, Val, Leu, Ile]
II. [with side chains containing hydroxylic
(OH) groups= Ser, Thr]
III. [with side chains containing sulphur
atoms = Cys, Met]
IV. [with side chains containing acidic
groups or their amides = Asp, Glu]
V. [with side chains containing basic groups
= Arg, Lys, His]
VI. [containing aromatic rings = His, Phe,
VII. [imino acids = Pro] 4.23 4.69
Sustainable Food Production Vol. 8 11
Table 5. Amino acid scores of kilishi based on whole hen’s egg amino acid
Table 6. Essential amino acid scores of kilishi based on FAO/WHO  standards
score Mean SD CV%
Met + Cys
Phe + Tyr
12 SFP Volume 8
Table 7. Essential amino acid scores of based on requirements of pre-school child (2-5years)
Met + Cys
Phe + Tyr
Table 8. Summary of the statistical analyses of the scores reported in Tables 5, 6 and 7
Egg scores versus
Egg score is significantly different at n-2 [n-2 = 19 – 2 = 17 (df)] and r= 0.01 (critical value = 0.575); provisional score is
significantly different at n-2 [n-2 = 9 – 2 = 7 (df)] and r= 0.01 (critical value = 0.798); pre-school child score is significantly
different at n-2 [n-2 = 10 – 2 = 8 (df)] and r= 0.01 (critical value = 0.765).
Sustainable Food Production Vol. 8 13
Table 9. Estimates of amino acid requirements at ages 10-12 years (mg kg-1 day-1)
30kg x R =
Ile 30 900 2628 -1728 -192
Leu 45 1350 4946 -3596 -266
Met+Cys 27 810 2312 -1502 -185
Trp 4 120 657 -537 -448
Total EAAs 261 7830 31215 -23385 -74.9
- T > S; T was calculated as: specific amino acid x 10 x appropriate corresponding protein value.
 E. C. Igwe, A. Nura, N. Abusalam, M. Dandago, J. E. Obiegbuna. Evaluation of production
techniques and quality assessment of kilishi in some parts of Kano, Kano state, Nigeria, Int. J.
Basic Sci. Tech. 1 (2015)35-38
 Using Kilishi - Nigerian meat jerky as a healthy snack for weight loss. Nigerian meat jerky as a
healthy snack for weight loss. Available: https:// www.africanweightloss.com>...
 Special Report, Nigeria’s meat of possibilities (video documentary) – Nigeria Today. 30 April,
 Nigeria, Kano – Kilishi is Everything to the People. Retrieved 7 July 2016.
 L. Umuoke, How to prepare Kilishi, InfoGuideNIGERIA.COM (Information Guide in Nigeria),
August 27, 2018.
 AOAC, Official Methods of Analysis, 18th ed., Association of Official Analytical Chemists,
Washington, DC, Method 982 – 30, 2006.
 P. O. Danka, D. T. Dobrina, V. I. Kalin, Simultaneous identification and determination of total
content of amino acids in food supplements – tablets by gas chromatography, Asian J. Pharm.
Clin. Res. 5(2) (2012) 57-68.
 O. Olaofe, E. T. Akintayo, Prediction of isoelectric point of legume and oil seed proteins from
their amino acid composition, The J. Technosci. 4 (2000) 49-53.
 R. H. Alsmeyer, A. E. Cunningham, M. L. Happich, Equations to predict PER from amino acid
analysis, Food Technol. 28 (1974) 24-38.
 B. L. Oser, An Integrated Essential Amino Acid Index for Predicting the Biological Value of
Proteins, in: A. A. Albanese (Ed.), Protein and Amino Acid Nutrition. Academic Press, New
York, 1959, pp. 281-295.
 A. A. Paul, D. A. T. Southgate, J. Russsel, First Supplement to McCance and Widdowson’s
The Composition of Foods: Amino acids, mg per 100g Food, fatty acids, g per 100g Food. HM
Stationary Off, London, 1978.
 FAO/WHO. Energy and protein requirements, Technical Report Series No 522, WHO, Geneva,
14 SFP Volume 8
 FAO/WHO/UNU, Energy and protein requirements, Technical Report Series No 724, WHO,
 F. H. Steinke, E. E. Prescher, D. T. Hopkins, Nutritional evaluation (PER) of isolated soybean
protein and combinations of food proteins, Journal of Food Science 45 (1980) 323-327.
 D. C. Nieman, D. E. Butterworth, C. N. Nieman, Nutrition. WC Brown Publishers, Dubuque,
 W. R. Akeson, M. Stahmann, A pepsin pancreatic index of protein quality evaluation, Journal
of Nutrition 83 (1964) 257 – 261.
 E. G. Abimorad, G. H. Squassoni, D. J. Carneiro, Apparent digestibility of protein, energy and
amino acids in some selected food ingridients for pacu Piaracious mesopotamicus, Aquacult.
Nutr. 14 (2008) 374 – 380.
 FAO/WHO, Protein quality evaluation, Report of Joint FAO/WHO Expert Consultation. Food
and Nutrition Paper 51, FAO, Rome, 1991.
 R. A. Oloyo, Fundamentals of research methodology and applied sciences, ROA Educational
Press, Ilaro, Nigeria, 2001.
 PubChem and the American Chemical Society, Reshaping Scholarly Communication,
University of Califonia, USA, 2005-05-31. Retrieved 2018-10-15.
 E. I. Adeyeye, Amino acid profiles of the flesh of the heterosexual pairs of Neopetrolisthes
maculatus, International Letters of Natural Sciences 61 (2017) 23-35.
 E. I. Adeyeye, Amino acid composition of whole body, flesh and exoskeleton of female
common West African fresh water crab Sudanautes africanus africanus, Pak J. Nutr. 7 (2008)
748 - 752.
 A. Sinclair, N. Mann, S. O’Connell, The Nutrient Composition of Australian Beef and Lamb,
RMIT, Melbourne, 1999.
 B. S. Schweigert, B. J. Payne, A Summary of the Nutrient Content of Meat, Bulletin No. 30,
American. Chicago: Meat Inst. Foundation, 1956.
 D. C. Mahan, R. G. Shields Jr., Essential and nonessential amino acid composition of pigs from
birth to 145 kilograms of body weight, and comparison to other studies, J. of Animal Science
76(2) (1998) 513 – 521.
 E. F. Beach, B. Munks, A. Robinson, The amino acid composition of animal tissue protein, J.
Biol. Chem. 148 (1943) 431 – 439.
 E. I. Adeyeye, Simultaneous identification and evaluation of amino acid profiles of the male
and female innards of Neopetrolisthes maculatus, International Letters of Natural Sciences 75
(2019) 13 – 26.
 FAO/WHO, Protein quality evaluation, Report of Joint FAO/WHO Consultation, Bethesda,
MD, 4-8 December, 1989, FAO/WHO, Rome, 1990.
 E. I. Adeyeye, The composition of the winged termites, Macrotermes bellicosus, Journal of
Chemical Society of Nigeria 30(2) (2005) 145-149.
 E. I. Adeyeye, Amino acid composition of variegated grasshopper, Zonocerus variegatus,
Tropical Science 45(4) (2005) 141-143.
 E. I. Adeyeye, E. O. Afolabi, Amino acid composition of three different types of land snails
consumed in Nigeria, Food Chemistry 85(4) (2004) 535 – 539.
 E. I. Adeyeye, The chemical composition of liquid and solid endosperm of ripe coconut.
Oriental Journal of Chemistry 20(3) (2004) 471-476.
Sustainable Food Production Vol. 8 15
 E. I. Adeyeye, S. S. Asaolu, A. O. Aluko, Amino acids composition of two masticatory nuts
(Cola acuminata and Garcinia kola) and snack nut (Anacardium occidentale), Int. J. Food
Science and Nutr. 58(4) (2007) 241 – 249.
 S. Bingham, Dictionary of Nutrition, Barrie and Jenkins, London, 1977.
 H. G. Muller, G. Tobin, Nutrition and Food Processing, Avi Publishing, Westport, CT, 1980.
 M. Friedman, Nutritional value of proteins from different food sources – A review, Journal of
Agriculture and Food Chemistry 44 (1996) 6 – 29.
 E. I. Adeyeye, M. A. Oyarekua, A. J. Adesina, Proximate, mineral, amino acid composition and
mineral safety index of Callinectes latimanus, International Journal of Development Research
4 (2014) 2641-2649.
 FAO, Sorghum and millets in human nutrition, FAO Food Nutrition Series No 27, FAO/UN,
 B. Belavady, S. G. Srikantia, C. Gopalan, The effect of oral administration of leuane on the
metabolism of tryptophan, Biochem. J. 87(1963) 652 – 655.
 B. Belavady, P. U. Rao, Leucine and Isoleucine Content of Jowar and its Pellagragenicity,
Indian Exp. Biol. 17(7) (1979) 659-661.
 Y. G. Deosthale, Nutrition dimension of high yielding and hybrid crop varieties: Locational and
varietal differences in nutritional value, in: FAO, FAO Food and Nutrition Series No 27,
Sorghum and Millets in Human Nutrition, FAO, p. 82.
 J. C. Cavins, D. F. Kwolek, G. E. Inglett, J. C. Cowen, Amino acid analysis of soybean meal:
interlaboratory study, Journal of Association of Official Analytical Chemists, 55 (1972) 686 –
 E. I. Adeyeye, M. O. Aremu, Amino acid composition of two fancy meats (Liver and Heart) of
African giant pouch rat (Cricetomys gambianus), Oriental Journal of Chemistry 27(4) (2011)
 A. A. Albanese, Protein and Amino Acid Requirements of Mammals, Academic Press, New
 H. H. Mitchell, A method for determining the biological value of protein, in: A.A. Albanese
(Ed.), Protein and Amino Acid Requirements of Mammals, Academic Press, New York, 1950,
pp. 1 – 32.
 P. B. Pencharz, J. W-C Hsu, R. O. Ball, Aromatic amino acid requirements in healthy human
subjects, The Journal of Nutrition (2007) 1 – 3.
 G. Schaafma, The protein digestibility-corrected amino acid score, J. Nutr. 130 (2000) 1865S –
 B. Walther, A. Schmid, R. Sieber, K. Wehmuller, Cheese in nutrition and health, Diary Science
and Technology 88(4 – 5) (2008) 389 – 405.
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