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The Phytochemical Composition and Some Biochemical Effects of Nigerian Tigernut (Cyperus esculentus L.) Tuber

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The phytochemical composition of the tigernut tuber and the effect of the aqueous extract on some biochemical parameters such as blood glucose, serum protein, albumin and cholesterol, white blood cells, red blood cells, haemoglobin, erythrocyte sedimentation rate and packed cell volume were determined in rats administered different concentrations of the extract. From the result of the phytochemical analysis, the presence of alkaloids, cyanogenic glycosides, resins, tannins, sterols and saponins were observed in the raw tuber, however only alkaloids, sterols and resins were observed in the roasted tuber. Analysis of the antinutrient composition yielded oxalates (0.25±0.65 g/100 g), phytate (1.97±0.81 mg/100 g), saponins (0.88±0.02/100 g), tannins (9.50±0.46 mg/100 g) and cyanogenic glycosides (1.80±0.69 mg/100 g). Roasting numerically decreased the levels of the anti-nutritive factors analyzed. At the end of the treatment period, the mean weights of the animals increased. The blood glucose level decreased significantly in concentration dependent manner (p<0.05) and serum albumin level increased significantly in a concentration dependent manner (p<0.05) in the groups administered the different concentrations of the extract. There was no significant effect (p>0.05) on serum cholesterol and protein and on total and differential white blood cell, red blood cell, haemoglobin, packed cell volume and erythrocyte sedimentation rate. The results therefore indicate the absence of undesirable effect in the use of the tigernut tuber even in the raw form at least at the administered concentration and for the duration of feeding. The findings are of nutritional, health and industrial relevance since the tuber is currently being used as food in many homes in Nigeria.
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Pakistan Journal of Nutrition 9 (7): 709-715, 2010
ISSN 1680-5194
© Asian Network for Scientific Information, 2010
Corresponding Author: Ekeanyanwu Raphael Chukwuma, Department of Chemical Sciences, Novena University, Ogume, Delta State,
Nigeria
709
The Phytochemical Composition and Some Biochemical Effects of
Nigerian Tigernut (Cyperus esculentus L.) Tuber
Ekeanyanwu Raphael Chukwuma , Njoku Obioma and Ononogbu Ikpendu Christopher
1 2 2
Department of Chemical Sciences, Novena University, Ogume, Delta State, Nigeria
1
Department of Biochemistry, University of Nigeria, Nsukka, Enugu State, Nigeria
2
Abstract: The phytochemical composition of the tigernut tuber and the effect of the aqueous extract on some
biochemical parameters such as blood glucose, serum protein, albumin and cholesterol, white blood cells,
red blood cells, haemoglobin, erythrocyte sedimentation rate and packed cell volume were determined in
rats administered different concentrations of the extract. From the result of the phytochemical analysis, the
presence of alkaloids, cyanogenic glycosides, resins, tannins, sterols and saponins were observed in the
raw tuber, however only alkaloids, sterols and resins were observed in the roasted tuber. Analysis of the
antinutrient composition yielded oxalates (0.25±0.65 g/100 g), phytate (1.97±0.81 mg/100 g), saponins
(0.88±0.02/100 g), tannins (9.50±0.46 mg/100 g) and cyanogenic glycosides (1.80±0.69 mg/100 g). Roasting
numerically decreased the levels of the anti-nutritive factors analyzed. At the end of the treatment period, the
mean weights of the animals increased. The blood glucose level decreased significantly in concentration
dependent manner (p<0.05) and serum albumin level increased significantly in a concentration dependent
manner (p<0.05) in the groups administered the different concentrations of the extract. There was no
significant effect (p>0.05) on serum cholesterol and protein and on total and differential white blood cell, red
blood cell, haemoglobin, packed cell volume and erythrocyte sedimentation rate. The results therefore
indicate the absence of undesirable effect in the use of the tigernut tuber even in the raw form at least at the
administered concentration and for the duration of feeding. The findings are of nutritional, health and
industrial relevance since the tuber is currently being used as food in many homes in Nigeria.
Key words: Cyperus esculentus, tigernut, phytochemicals, biochemical effects
INTRODUCTION
The worsening food crisis and the consequent wide
spread prevalence of malnutrition in developing and
underdeveloped countries have resulted in high mortality
and morbidity rates, especially among infants and
children in low income groups (Enujuigba and Akanbi,
2005). The reliance on starchy roots and tubers and
protein deficient cereals as main staples results in
consumption of non-nutritious foods. The insufficient
availability of nutrient rich diets and high cost of available
ones have prompted an intense research into
harnessing the potentials of the lesser known and
underutilized crops, which are potentially valuable for
human and animal foods to maintain a balance between
population and agricultural productivity, particularly the
tropical and subtropical areas of the world.
Cyperus esculentus (Tigernut) is an underutilized plant
of the family Cyperaceae, which produces rhizomes
from the base and tubers that are some what spherical
(Cortes et al., 2005). The plant is not really a nut but a
tuber first discovered some 4000 years ago (Lowe and
Whitewell, 2000). It has other names like yellow
nutsedge, chufa, flatsedge, rush nut, water grass, earth
almond, northern nut grass and nut grass (Shilenko et
al., 1979). Cyperus esculentus is known in Nigeria as
aya in Hausa, ofio in Yoruba and akihausa in Ibo.
Cyperus esculentus grows mainly in the middle belt and
northern regions of Nigeria (Okafor et al., 2003), where
three varieties (black, brown and yellow) are cultivated
(Umerie et al., 1997). Among these, only two varieties,
yellow and brown are readily available in the market. The
yellow variety is preferred to all other varieties because
of its inherent properties like its bigger size, attractive
colour and fleshier body (Belewu and Abodurin, 2006).
Cyperus esculentus can be eaten raw, roasted, dried,
baked or be made into a refreshing beverage called
kuunu (Oladele and Aina, 2007).
Cyperus esculentus was reported as healthy and helps
in preventing heart, thrombosis and activates blood
circulation. It helps in preventing cancer, due to high
content of soluble glucose. It was also found to assist in
reducing the risk of colon cancer (Adejuyitan et al.,
2009). The nut is rich in energy content (starch, fat,
sugars and protein), mineral (phosphorus, potassium)
Pak. J. Nutr., 9 (7): 709-715, 2010
710
and vitamins E and C (Belewu and Belewu, 2007).
Cyperus esculentus is suitable for diabetic persons and
also helps in loosing weight (Borges et al., 2008).
Food contains various compositions of nutrients and
antinutrients and could have important or deleterious
effects in the body when consumed. The composition of
the nutrients and antinutrients, usually leads to side
effects found in most plants which may lead to toxicity,
hyperlipidaemia, excessive weight gain, hyperglycaemia,
carotenemia, constipation, kidney stones, body odour,
bad breath, allergies, diarrhoea, frequent urination and
acne (Anonymous, 2009). In most of these side effects,
the biochemical and haematological parameters are
usually altered. For a food to be considered safe for
human and animal health, its effect on these
parameters need to be investigated to understand the
nutritional potentials and safety of such foods with a view
to determining their acceptability.
The aim of the present study is to determine the
phytochemical composition of the tuber and to ascertain
if the tuber could have beneficial effect on biochemical
parameters such as blood glucose, serum albumin,
protein, cholesterol, red blood cell, haemoglobin,
erythrocyte sedimentation rate, packed cell volume, and
total and differential white blood cell of the rats as our
model for the research.
MATERIALS AND METHODS
Collection and preparation of tigernut tuber flour and
the aqueous extract: Fresh tigernut tuber was
purchased from a local market in Katsina, Katsina state,
Nigeria. The tuber was identified and authenticated by Mr
A. Ozougwu of Botany department, university of Nigeria,
Nsukka, Enugu state. The tigernut tubers were cleaned,
sorted and washed. The fresh tubers were dried in an
oven (GallenKamp, England) at 37 C for one hour,
o
milled separately using a laboratory electric mill (Retsch,
5657, GmbH, Germany) to pass through a 40-mesh
sieve, packaged in glass jars and stored at 4C in a
o
refrigerator until analysis. A Quantity, 400 g of the fresh
milled tubers was extracted by shaking it with 3 litres of
n-hexane for one hour, three times to remove the oil. The
defatted milled tubers were dried in a desiccator under
vacuum. The water extract was obtained by stirring the
dry defatted milled tubers with seven (7) litres of distilled
water at room temperature (27±1 C) for twelve hours.
o
The suspension was centrifuged at 3000 rpm for 10 min
and the supernatant was filtered through white muslin
cloth and then whatman filter paper No.1 under vacuum.
The extract was concentrated using water bath at an
optimum temperature of 65 C to avoid the denaturation
o
of the bioactive compounds. The weight of the dry extract
was determined. The different concentrations (500,
1000, 1500 and 2000 mg/kg) of the extract were
prepared.
Table 1: The phytochemical composition of the tigernut tuber
Phytochemical Raw Roasted
Alkaloids +++ +
Glycosides - -
Cyanogenic glycosides + -
Resins +++ +++
Flavonoids - -
Cardiac glycosides - -
Tannins + -
Sterols +++ +++
Saponins + -
+++ = Present in very high concentration, ++ = Present in
moderately high concentration, + = Present in trace
concentration, - = Not detected
Experimental animals: Adult male Wistar albino rats
were purchased from the faculty of biological sciences
animal house, University of Nigeria, Nsukka, Enugu
state, Nigeria. The animals were about 12 weeks with
average weight of 112.37±11.7 g. The animals were kept
under standard conditions for 7 days with free access to
water and food before starting the experiment. Albino
mice, 20.50±4.27 g weights were used for the acute
toxicity tests. The animals were housed in standard
cages with food and water ad libitum at room
temperature and provided with pelletized feed.
Experimental design: An acute toxicity study of the
aqueous extract of tigernut was done by the method of
Lorke (1983). Twenty five (25) male Wistar albino rats of
12 weeks were divided into five groups of five rats each
of average weight were randomly assigned to five (5)
cages labelled I, II, III, IV and V respectively and kept at
room temperature (25 C). All the rats were allowed free
o
access to water and feed ad libitum for a week to
acclimatize them to laboratory conditions. After this
period, the control animals (group I) were administered
0.2 ml of normal saline (0.9% NaCl) while groups II, III,
IV and V were administered different concentrations of
the extract. The extracts were administered for 30 days
to the animals using the oral route by means of
polythene cannula. The weights of the animals were
taken before commencement of the feeding experiment
and then later every six days interval. At the end of the 30
days, blood samples from each rat were collected
through the orbital technique for analysis of
haematological parameters like total and differential
white blood cells, red blood cell, haemoglobin, packed
cell volume, erythrocyte sedimentation rate and
biochemical parameters like blood glucose, serum
protein, albumin and cholesterol.
Phytochemical analysis: The phytochemical test for the
presence and absence of saponins, alkaloids,
flavonoids, cyanogenic glycosides, tannins, glycosides,
and sterols were carried out according to the method
described by Harbone (1984).
Pak. J. Nutr., 9 (7): 709-715, 2010
711
Antinutrient analysis: Percentage compositions of 1984) as most of these phytochemicals are thermally
some antinutrients like oxalates, phytates, cyanogenic unstable.
glycosides, saponins and tannins were determined by Analysis of the antinutrients composition of the raw
the method described by AOAC (1990). All tubers of C. esculentus showed that it contained
determinations were done in triplicate determination. 0.60±0.32 g/100 g oxalates, 2.40±0.40 mg/100 g
Biochemical studies: Serum cholesterol was g/100 g tannins and 1.08±0.69 mg/100 g cyanogenic
determined by the method of Meiatini et al. (1978), glycosides. The roasted C. esculentus tuber contained
serum total protein by the method of Wooten (1964), 0.55±0.36 g/100 g oxalates, 1.06±0.24 mg/100 g phytate,
blood glucose by the glucose oxidase method of Marks 0.67±0.40 mg/100 g saponins, 7.10±0.35 g/100 g
and Dawson (1965), serum albumin by the method of tannins and 0.86±0.44 mg/100 g cyanogenic glycosides.
Doumas et al. (1971). The levels of antinutrients analyzed were very low
Haematological studies: The haemoglobin (Ejigui et al., 2005). The presence of phytates in
concentration was estimated using the cyanome- biological systems may chelate divalent metals like
thaemoglobin photometric method. The packed cell calcium, magnesium, or block the absorption of
volume was estimated using the micro-haematocrit essential minerals in the intestinal tract (Dan, 2005)
centrifuge. The red blood cell and differential white blood thus decreasing their bioavailability (Oberleas, 1973).
cell was estimated using the improved Neubauer Phytates chelate with mineral elements thereby having
haemocytometer. Erythrocyte sedimentation rate was significant effects on the utilization of the minerals. They
determined using the Westergren method (1957). also react with basic residues of protein. Tannins and to
RESULTS AND DISCUSSION
The result of phytochemical screening shows that a
higher content of alkaloids, sterols and resins than
cyanogenic glycosides, saponins and tannins were
detected in the raw Tigernut tuber. However, in the
roasted Tigernut tuber, only alkaloids sterols and resins
were detected and no other phytochemical assayed was
detected. Alkaloids, saponins and tannins are known to
have antimicrobial activity, as well as other physiological
activities (Sofowora, 1993; Evans, 2005). Alkaloids are
known for their toxicity, but not all alkaloids are toxic.
They inhibit certain mammalian enzymic activities such
as those of phophodiesterase, prolonging the action of
cAMP. They also affect glucagons and thyroid stimulating
hormones, while some forms have been reported to be
carcinogenic (Okaka et al., 1992). Some have been used
either as an analgesic, antispasmodic, bactericidal
agents (Frantisek, 1991). Saponins have been reported
to be useful in reducing inflammation of upper
respiratory passage and also chiefly as foaming and
emulsifying agents and detergents (Frantisek, 1991).
Tannins have astringent properties that hasten the
healing of wounds and prevention of decay. Tannin
compounds have antimicrobial activities and are
responsible for preventing and treating urinary tract
infections and other bacterial infections. The result of the
determination of phytochemical test indicated that the
tuber possess some biologically active compounds
which could serve as potential source of vegetable
drugs in herbal medicine. These phytochemicals exhibit
diverse pharmacological and biochemical actions when
ingested by animals (Amadi et al., 2006). They are
usually present at low concentration in edible fruits, nuts,
tubers and vegetables. Roasting reduced the amount of
these phytochemicals in plant products (Piorrock et al.,
phytates, 0.88±0.02 mg/100 g saponins, 9.62±0.29
compared to those reported for nuts like the peanuts
some extent oxalates, binds to proteins thereby making
them difficult to digest in the body. Oxalates can remove
calcium in the form of calcium oxalate (Savage, 1993) in
the blood and thus may result to kidney damage.
Saponin reduces the uptake of certain nutrients
including glucose and cholesterol at the gut through
intra-lumenal physicochemical interaction (Price et al.,
1987). They also exhibit structure dependent biological
activity (Savage, 1993). The potential toxicity of a food
produced from a cyanogenic plant depends on the
likelihood that its consumption will produce a
concentration of Hydrogen Cyanide (HCN) that is toxic to
exposed humans. Cyanide causes an increase in blood
glucose and lactic acid levels and a decrease in the
ATP/ADP ratio indicating a shift from aerobic to
anaerobic metabolism. Cyanide also activates
glycogenolysis and shunts glucose to the pentose
phosphate pathway decreasing the rate of glycolysis and
inhibiting tricarboxylic acid cycle (Akintonwa and
Tunwashe, 1992). Odumodu (1992) and Okafor et al.
(2003) had earlier reported low contents of these
antinutrients in tigernut tuber flour compared with other
local fruits, nuts, tubers and vegetables. Roasting
numerically reduced the antinutrient composition of
tigernut tuber flour.
Acute toxicity test are generally the first test conducted in
any toxicity study. They provide data on the relative toxicity
likely to arise from a single or brief exposure to any
substance. Different plant extracts have been known to
possess different levels of toxicity which majorly
depends on the levels of antinutrients inherent in the
plants (Sofowora, 1993). Preliminary investigations on
the acute toxicity of the tuber extract of C. esculentus in
mice showed that the aqueous extract of C. esculentus
(tigernut) tuber was not toxic to mice at the administered
concentrations.
Pak. J. Nutr., 9 (7): 709-715, 2010
712
Table 2: The antinutrient composition of the tigernut tuber
Components
------------------------------------------------------------------------------------------------------------------------------------------------------------
Oxalates Phytate Saponin Tannins Cyanogenic glycosides
Sample (g/100 g) (mg/100 g) (g/100 g) (mg/100 g) (mg/100 g)
Raw 0.60±0.32 2.40±0.40 0.88±0.02 9.62±0.29 1.08±0.69
Roasted 0.55±0.36 1.06±0.24 0.67±0.40 7.10±0.35 0.86±0.44
Values are mean±standard deviation of triplicate determination
Table 3: The biochemical parameters of the animals at the end of experimental period
Groups
------------------------------------------------------------------------------------------------------------------------------------------
Group II Group III Group IV Group V
Parameters Group I NS 500 mg/kg 1000 mg/kg 1500 mg/kg 2000 mg/kg
Blood glucose (g/dl) 71.5±4.04 60.25±3.40* 56.75±2.50* 54.00±3.46* 48.50±4.66*
Serum protein (g/dl) 6.92±0.27 7.43±0.63 7.39±0.45 7.16±0.61 7.19±0.35
Serum albumin (g/dl) 3.35±0.48 3.14±0.72 4.08±0.29* 4.18±0.31* 3.93±0.30*
Serum cholesterol (mg/dl) 88.10±15.12 86.49±17.65 91.35±3.24 75.94±18.89 79.91±8.79
Values are mean±standard deviation of quintuplicate determination, *Means significant different (p<0.05) compared to the control.
N = 5, NS = Normal Saline
The result of the effect of administration of the various haematological parameters such as red blood cells,
concentrations (500, 1000, 1500 and 2000 mg/kg) of C. total and differential white blood cells, haemoglobin,
esculentus tuber extract on biochemical parameters packed cell volume and erythrocyte sedimentation rate
such as blood glucose, serum protein, albumin and is presented in Table 4. The result show that there was
cholesterol are presented in Table 3. The result showed no significant effect (p>0.05) on these haematological
that there was significant increase (p<0.05) in serum parameters. The results obtained for all treatment
albumin and a significant decrease (p<0.05) in blood groups indicate nutritional adequacy of the tuber extract
glucose, but there was no significant effect (p>0.05) on and the rat diet since they did not indicate malabsorption
serum protein and cholesterol. Since total serum or under nutrition (Church et al., 1984). These
proteins and albumin are generally influenced by total observations were related to the composition of the
protein intake (Onifade and Tewe, 1993), the results tuber extract and health status of the animals since none
obtained indicate nutritional adequacy of the dietary and of the animals died as a result of any diseases.
the extract proteins. Abnormal serum albumin usually Hackbath et al. (1983) had earlier recorded a strong
indicates an alteration of normal systemic protein influence of food components on haematological traits,
utilization (Apata, 1990). Awosanya et al. (1999) have packed cell volume and haemoglobin concentration
demonstrated the dependence of blood protein on the being very strong indicators of nutritional status of
quality and quantity of protein source. The reported low animals. It is well known that various antinutritional
level of phytate in the tuber could also have led to the substances and xenobiotics can cause haemolysis,
increased absorption of protein from the rat diet. Phytate nutrients malabsorption and abnormal haemopoesis
acts as a chelator, forming proteins and mineral which could arise from liver damage (Chubb, 1982),
bioavailability (Davies and Gathlin, 1991). Since glucose antinutrient analysis of the tigernut tuber shows that it
level was significantly (p<0.05) lowered and cholesterol has low concentration of these antinutrients. The result
levels were not affected abnormally, possibilities of of the total and differential white blood cell count indicate
anorexia, diabetes, liver dysfunction and mal-absorption that the animals were healthy because decrease in
of fat, which are the symptoms of abnormal glucose and number of white blood cells is an indication of allergic
cholesterol levels in blood (Bush, 1991) are ruled out. conditions, anaphylactic shock and certain parasitism
The glucose lowering potentials of the extract may be while elevated value indicate to the existence of a recent
ascribed to modifications in glucose uptake in the infection, usually with bacteria (Ahamefule et al., 2008).
intestine. It is well known that soluble fibres generally The mean body weight change in rats after every six
increase transit time through the gut, slow emptying of days following administration of 500, 1000, 1500 and
the stomach and slow glucose absorption 2000 mg/kg body weight extract of C. esculentus tuber
(Swaminathan, 2002). Cyperus esculentus tubers have extract are presented in Table 5. A general increase in
high dietary fibre content (Umerie and Enebeli, 1997), so physical activities, food and water intake were observed
they may play a major role in lowering blood glucose for all the animals during the feeding experiment. There
level. This observation supports an earlier hypothesis was initial increase in weight which was sustained. The
that the tuber may be important for diabetics and those increased weight could be due to increased feed and
seeking to reduce weight (Kordyias, 1990). water intake observed all through the experimental
The result of the effect of administration of the various period. The increase in weight of the animals suggests
concentrations (500, 1000, 1500 and 2000 mg/kg) of C. that they increasingly accumulated calories from the
esculentus (tigernut) aqueous tuber extract on normal rat diet and from the nutrient rich extracts.
Pak. J. Nutr., 9 (7): 709-715, 2010
713
Table 4: The red blood cell count, total and differential white blood cell count haemoglobin concentration, erythrocyte sedimentation
rate and packed cell volume of the animals at the end of experimental period
Group II Group III Group IV Group V
Haematological indices Group I NS 500 mg/kg 1000 mg/kg 1500 mg/kg 2000 mg/kg
RBC (x10 /µL) 8.50±0.19 8.74±0.58 8.63±0.67 8.54±1.55 8.67±0.15
6
Hb (g/dl) 17.25±1.28 16.94±1.29 16.99±0.95 17.71±1.00 17.91±0.63
PCV (%) 44.37±2.56 46.00±1.08 45.63±4.23 45.00±0.00 44.13±1.32
ESR (mmHr) 0.76±0.12 0.73±0.07 0.82±0.10 0.70±0.55 0.69±0.07
tWBC (x10 /µL) 13.96±2.64 13.51±1.82 13.57±2.72 16.61±2.72 14.53±1.33
3
Neutr (x10 /µL) 2.78±0.82 2.52±0.46 1.59±0.44 2.77±1.00 3.18±1.24
3
Lymph (x10 /µL) 10.69±1.88 10.73±1.50 11.62±2.61 13.38±2.62 11.03±1.42
3
Eosin (x10 /µL) 0.06±0.07 0.07±0.08 0.11±0.13 0.09±0.10 0.00±0.00
3
Mono (x10 /µL) 0.39±0.20 0.24±0.15 0.24±0.18 0.33±0.13 0.18±0.67
3
Baso (x10 /µL) 0.03±0.06 0.03±0.07 0.00±0.00 0.40±0.80 0.12±0.15
3
Values are mean±standard deviation of quintuplicate determination, *Means significant different (p<0.05) compared to the control.
N = 5, NS = Normal Saline. RBC = Red Blood Cell, Hb = Haemoglobin, PCV = Packed Cell Volume, ESR = Erythrocyte Sedimentation
Rate, tWBC = total White Blood Cell, Neutr = Neutrophil, Lymph = Lymphocyte, Eosin = Eosinophil, Mono = Monocytes, Baso = Basophils
Table 5: The mean body weight of rat administered aqueous tuber extract of tigernut
Group II Group III Group IV Group V
Periods Group I NS 500 mg/kg 1000 mg/kg 1500 mg/kg 2000 mg/kg
0 day 113.25±15.09 113.50±6.62 114.74±12.20 111.24±9.62 110.47±5.83
6 day 138.05±8.00 115.20±9.97 139.00±16.02 121.50±17.65 134.40±13.00
th
12 day 147.30±11.47 130.32±9.35 142.94±15.35 125.38±17.26 139.34±12.42
th
18 day 157.07±8.60 141.90±8.20 149.40±14.57 133.90±17.92 152.14±14.02
th
24 day 160.15±9.47 143.80±9.30 158.10±15.06 141.02±18.45 159.14±15.40
th
30 day 174.95±7.61 149.92±10.45 166.48±15.87 148.36±19.06 171.28±11.53
th
Values are mean±standard deviation of quintuplicate. N = 5, NS = Normal Saline
Although the animals used in this study were fed with Ahamefule, F.O., B.E. Obua, I.A. Ukweni, M.A. Oguike and
normal rat diet, the tigernut tuber extract might have
allowed proper absorption of the nutrients which have
allowed proper utilization of the nutrients. Low level of
active/toxic principles may have stimulated appetite and
increased feed utilization resulting in increased weight
gain. The tuber of C. esculentus is used in making a
refreshing beverage called kuunu in Nigeria which is
consumed mostly in the Northern region of Nigeria
(Belewa and Abodurin, 2008). There have not been any
reported cases of toxicity in humans.
The present study confirms the tigernut tuber contains
important nutrients and some essential macro and
micro nutrient necessary for good human and animal
health. Roasting the tuber as a processing step reduced
the antinutrients composition. But unlike several other
underutilized crops, it does not produce any undesirable
effects even when consumed raw. The findings indicate
that the tigernut tuber which is popularly eaten raw is rich
in important food properties when compared with other
crops has no negative effect, at least in rats and
considering the economic situation in Nigeria and the
near zero economic value of this tuber, its cultivation and
consumption should be encouraged.
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... In addition, there are a variety of active components in Cyperus, such as volatile oil, organic acids, alkaloids, phenols, terpenoids, anthraquinone, steroids, etc., which have antibacterial, antioxidant and antitumor activities. It was reported that the consumption of Cyperus could help prevent heart disease and thrombosis, improve blood circulation and lower the risk of colon cancer [7]. At the same time, a variety of active components in Cyperus have strong allelopathic effects, which have a great impact on intercropping, interplanting and crop rotation. ...
... Resins +++ [7,26] Cyanogenic glycosides + [7,26] Alkaloids +++ [7] Glycosides 0 ...
... Resins +++ [7,26] Cyanogenic glycosides + [7,26] Alkaloids +++ [7] Glycosides 0 ...
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Cyperus (Cyperus esculentus L.) is an edible perennial grass-like plant, which propagates exclusively with underground tubers. Its tubers are rich in starch (20–30%), fat (25–35%), sugar (10–20%), protein (10–15%) and dietary fiber (8–9%). In addition, the tubers also contain alkaloids, organic acids, vitamins (C and E), steroids, terpenoids and other active components. The contents of oleic acid and linoleic acid in Cyperus oil are very high, which have important medicinal value and health-promoting properties. Most of the extracts from the tubers, stems and leaves of Cyperus have allelopathic potential and antibacterial, antioxidant and insecticidal activities. In recent years, the planting area of Cyperus has increased significantly all over the world, especially in China and some other countries. This paper presents the current status of Cyperus and the recent trend in research in this area. Published reports on its nutritional contents, active ingredients, medicinal efficacy, antibacterial activity and allelopathic potential were also reviewed.
... Tiger nut can accumulate a great amount of nutrients in its underground tubers, including 25-40% starch, 20-30% oil, 15-20% sugars, and 5-10% protein, and high levels of dietary fibers (8-10%), vitamin C and E (0.08-0.14 g·kg 1), and minerals, such as calcium, phosphorus, and potassium [1,2,6,10,11]. The tubers are also rich in several bioactive substances such as phytosterols, alkaloids, saponins, tannins, flavonoids, and terpenoids [12,13]. Abundance of nutrients and bioactive compounds in the tubers signifies tiger nut as a valuable crop offering nutritional and health benefits both as human food and animal feed [2,6,13,14]. ...
... The tubers are also rich in several bioactive substances such as phytosterols, alkaloids, saponins, tannins, flavonoids, and terpenoids [12,13]. Abundance of nutrients and bioactive compounds in the tubers signifies tiger nut as a valuable crop offering nutritional and health benefits both as human food and animal feed [2,6,13,14]. It was reported that consumption of tiger nut is beneficial to patients with diabetes, cardiovascular disease, and obesity, as it can help boost blood circulation, lessen cardiovascular diseases and thrombosis, prevent stroke and inflammation of the respiratory passages, and reduce the risk of colon cancer [2,[13][14][15]. ...
... Abundance of nutrients and bioactive compounds in the tubers signifies tiger nut as a valuable crop offering nutritional and health benefits both as human food and animal feed [2,6,13,14]. It was reported that consumption of tiger nut is beneficial to patients with diabetes, cardiovascular disease, and obesity, as it can help boost blood circulation, lessen cardiovascular diseases and thrombosis, prevent stroke and inflammation of the respiratory passages, and reduce the risk of colon cancer [2,[13][14][15]. In ancient Egypt, China, and India, tiger nut tubers were also consumed as a liver tonic for healing of stomach pain, mouth and gum ulcers, and as an aphrodisiac for improvement of the human reproductive system [6]. ...
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Tiger nut (Cyperus esculentus L.) has recently attracted increasing interest from scientific and technological communities because of its potential for serving as additional source of food, oil, and feed. The present study reports morphology and biochemical characterization of 42 tiger nut accessions collected from China and other counties performed in the 2020 and 2021 growing seasons at Nongan, Jilin Province. Assessment of variability of 14 agronomic traits including plant height, maturation, leaf width, tilling number, color, size, and shape: 100-tuber weight showed a wide range of phenotypic variation. The color, size, and shape and maturation of the tubers, as well as the leaf width, were the most distinct characteristics describing variation among the accessions. Compositional analyses of major nutritional components of the tubers reveals that this crop could be a source of high-value proteins, fatty acids, and carbohydrates. Specifically, tiger nut tubers contained high levels of starch, oil, and sugars, and significant amounts of fiber, Ca, P, and Na. Furthermore, the tubers appeared to be a good source of proteins as they contain 16 amino acids, including the essential ones. Amino acid profiles were dominated by aspartic acid followed by glutamic acid, leucine, alanine, and arginine. Overall, these results demonstrated that tiger nut is well adapted to the temperature and light conditions in the north temperate zone of China, even with a shorter growth season. The tiger nut accessions collected here exhibited wide variations for agronomical and biochemical traits, suggesting potential for potential for breeding improvement by maximizing the fresh tuber and grass yield based on the optimal selection of genetic characteristics in climate and soil conditions of northern China.
... Food contains various compositions of antinutrients and nutrients and could have important or deleterious effects in the body when consumed. Tigernuts tuber oil contains about 18% saturated fatty acids (palmitic acid and stearic acid) and about 82% unsaturated fatty acids (oleic acid: omega 9, and linoleic acid: omega 6) (Bosch et al. 2005;Dubois et al. 2007;Arafat et al. 2009;Chinma et al. 2009;Chukwuma et al. 2010;Adejuyitan et al. 2011). This olive oil-like composition shows that tigernut tuber oil is a potential substitute for it (Dubois et al. 2007;Adejuyitan 2011). ...
... tigernuts milk) were rated similar in almost all quality attributes, indicating the possibility of adding tigernuts milk to cow's milk in nutrient production and inexpensive yogurts (Sanful 2009). C. exculentus is a highly valued crop species which is widely used for food purposes (Chukwuma et al. 2010;Adejuyitan 2011). Owing to its high nutritional benefit, and local availability, the promotion of this species can substantially contribute to reduce malnutrition caused by lack of micronutrients in Africa and reach out the Sustainable Development Goals related to poverty, zero hunger and well-being. ...
... Food contains various compositions of antinutrients and nutrients and could have important or deleterious effects in the body when consumed. Tigernuts tuber oil contains about 18% saturated fatty acids (palmitic acid and stearic acid) and about 82% unsaturated fatty acids (oleic acid: omega 9, and linoleic acid: omega 6) (Bosch et al. 2005;Dubois et al. 2007;Arafat et al. 2009;Chinma et al. 2009;Chukwuma et al. 2010;Adejuyitan et al. 2011). This olive oil-like composition shows that tigernut tuber oil is a potential substitute for it (Dubois et al. 2007;Adejuyitan 2011). ...
... tigernuts milk) were rated similar in almost all quality attributes, indicating the possibility of adding tigernuts milk to cow's milk in nutrient production and inexpensive yogurts (Sanful 2009). C. exculentus is a highly valued crop species which is widely used for food purposes (Chukwuma et al. 2010;Adejuyitan 2011). Owing to its high nutritional benefit, and local availability, the promotion of this species can substantially contribute to reduce malnutrition caused by lack of micronutrients in Africa and reach out the Sustainable Development Goals related to poverty, zero hunger and well-being. ...
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Food security relies mainly on a few major crop species such as wheat, maize and rice, cassava and yam. Many of the cultivated plant species such as Tigernut (Cyperus exculentus) are still considered invasive plants and are neglected and underutilized. However, they may play a crucial role in food security, nutrition, and income generation among poor rural people. In the perspective to valorization of the species, this systematic review aimed at identifying the biology, production constraints and uses of tiger-nut for future research directions. Extensive searches were carried out and studies were screened and extracted using established systematic review methods. A total of 175 papers from Africa, America, Asia, and Europe met the inclusion criteria. Thematic synthesis was used to synthesis data and findings are presented under three framework aspects. Approximately 52% of the studies were undertaken in Europe while 21.71% were undertaken in Africa. Most of the papers reviewed for the study were published between [2010 and 2015]. The results highlighted the critical research gaps in ecology, plant demography, genetic diversity using SSR makers, genomics and evolutionary biology. Further, production constraints and solution approaches for the conservation and promotion of the species were the other gaps identified in the reviewed studies. Production constraints were specifically related to the insufficient mineral fertilizers, difficult in harvesting and post-harvest losses. Tiger-nut is used in more fields such as food, medicinal, cosmetic, biofuel and fishing and fish breeding. Such investigations would help in decision-making and elaboration of breeding strategies, and advancing steps towards sustainable use and the valorization of the species.
... Tiger nut (Cyperus esculentus Lativum) is an edible perennial sedge plant and is a lesser known root vegetable that produces sweet nut like tubers (Chukwuma, Obiama, and Christopher, 2010). This tuber is rich in energy content such as starch, fat, sugar, and protein. ...
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Tiger nuts are essential nuts and locally grown food source for fighting malnutrition in places like Africa. The nut is of high quantity of starch, fiber content and rich in minerals and vitamins, especially vitamins C and E. Besides, there are many important amino acids coupled with some B-complex vitamins. Tiger nut is known to control some health-related problems. However, there is inadequate information on its production under cottage or mobile gardening system. Hence, this study evaluated the yield of tiger nut using inorganic and organic fertilizers using polythene bags. An open space of building's corridor was used for the experiment between February and May 2020, at School of Vocational Education Building complex of Michael Otedola College of Primary Education Noforija-Epe, Lagos State. Experimental treatments applied are: No Fertilizer Application (NFA-0), (NPK; 3g, 5g), and Poultry Manure (PM; 15g and 30g) per 5kg soil, respectively. The experiment was laid in Complete Randomized Design (CRD), and the treatments were replicated thrice. Data on growth parameters; plant height (PH cm) Number of leaves (NL), Tillers per Plant (TP) were collected bi-weekly. The yield parameters observed are: Fresh Nutrient weight (FNw g/kg), biomass weight leaves (Bw g/5kg) and number of nuts. The plant height (PH), Plant Tiller (PT) and Number of Leaves (NL) values does not show a major significant yield under NFA while polythene bags with the application of different levels of organic and inorganic fertilizer shows a major significant yield in terms of number of nut and tiger nut weight. It can be concluded that the application of either organic or chemical fertilizers (Poultry Manure) at any of the levels between 15g to 30g for poultry and 3g to 5g NPK per 5kg polythene bag are more appropriate for tiger nut production at any open space at home. In conclusion, it is recommended that tiger nut can be produced for small household consumption under the potting conditions at home.
... The yellow variety also yields more milk, contains lower fat and higher protein and less anti-nutritional factors especially polyphenols (Okafor, 2003). Tiger nut has been reported to be a health food since its consumption can help prevent heart disease, thrombosis, activate blood circulation (Chukwuma, et al., 2010) and assist in reducing the risk of colon cancer (Adejuyitan et al., 2009). The tiger nut tuber is rich in energy content (such as starch, fat, sugar, and protein), minerals (mainly phosphorus and potassium), and vitamins E and C (Belewu and Belewu, 2007) thus making this tuber also suitable for diabetics and for those who wants to lose weight (Borges et al., 2008). ...
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Innovativenes is critical to the success of any business venture. The current study examined the innovative practices adopted by some informal businesses across three sectors in the Nigerian economy: manufacturing, agriculture and services. Primary data were obtained from business owners and managers in the informal business sector in Nigeria. Simple random sampling technique was used to select 778 respondents in three (3) out of six (6) geopolitical zones in Nigeria. Data collection were done with the aid of Google form. The overall aim of the survey was to provide information on the innovation activities of enterprises in the informal business sector. The retrieved data were analyzed using frequency counts and percentage distribution. Findings revealed that majority (76.5%) of the respondents attested that their customers were satisfied with current products, and were willing to pay for and interested in new products. This was closely followed by respondents (66.5%) who introduced environment-friendly products or services. About 60.8% of the respondents changed/upgraded technology (tools & equipment), looked for and used new sources for supply of raw materials and tools that were cheaper and/or better than old sources of supply. The study indicated that frequent changes in policies and government as well as civil unrest and crises are some of the factors hindering innovation activities in informal businesses. Cost of acquiring modern technologies and funding was ranked highest among economic factors that hindered innovation.
... Among these, only two varieties of tigernut are readily available in the market, which is the yellow and brown tigernut. Tigernut is very high in dietary fiber content (Joy-Toran & Farre-Rovira, 2003), which could be effective in treatment and prevention of many diseases including colon cancer (Adejuyitan, Otunola, Akande, Bolarinwa, & Oladokun, 2009), coronary heart disease (Chukwuma, Obioma, & Ononogbu, 2010), obesity, diabetes, gastrointestinal disorders (Anderson et al., 2009) and losing weight (Borges, Goncalves, Sgeoeiro, Correia, & Silva, 2008). ...
... 7 Tiger nut has been reported to have some medicinal effects, such as activation of blood circulation, and prevention of heart disease and thrombosis. 8 Other health benefits that have been attributed to tiger nut include reduction in the risk of colon cancer 7 , relief of indigestion due to its fibre content, benefit to diabetics, reduction in cholesterol, and stimulant effects 5 . ...
Article
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Food insecurity and undernourishment constitute a major challenge in Africa and the world at large. To meet key nutritional targets and tackle the menace of undernourishment, we need to exploit available but underutilised food crops. A common underutilised food crop with the potential to improve daily nutrition is tiger nut. This potential is evidenced in the number of essential amino acids detected, which constitute 74.425% of the entire amino acids detected, in addition to important minerals and vitamins. The nutritional composition of the yellow variety of tiger nut (Cyperus esculentus) was determined using the standard methods of high-performance liquid chromatography and UV-spectroscopy. Ten amino acids were identified and quantified, including six essential amino acids, of which valine had the highest concentration (67.59 μg/100 g), followed by leucine (3.019 μg/100 g), phenylalanine (1.767 μg/100 g), lysine (0.946 μg/100 g), histidine (1.048 μg/100 g) and tryptophan (0.055 μg/100 g). The other amino acids were proline (24.124 μg/100 g), cysteine (1.269 μg/100 g), glycine (0.024 μg/100 g), and glutamine (0.022 μg/100 g). Monosaccharides detected were ribose (41.76%), glucose (21.52%), sedoheptulose (17.94%), fructose (4.566%), rhamnose (1.78%) and mannose (1.58%), whilst disaccharides detected were sucrose (87.66%) and maltose (11.39%). Mineral concentrations were K 144.80 ± 1.10 mg/100 g, Ca 94.39 ± 0.02 mg/100 g, Na 83.92 ± 0.04 mg/100 g, Fe 19.36 ± 0.54 mg/100 g, Mg 17.63±0.13 mg/100 g, Cu 13.28±0.05 mg/100 g and Zn 5.18±0.01 mg/100 g Vitamins A, B2, C and E were detected and quantified as 53.93±1.03, 7.61±1.20, 31.70±1.25 and 128.75±0.74 μg/100 g, respectively. The chemical and nutritional properties of the yellow variety of tiger nut suggest that it is rich in essential amino acids, minerals, and some vitamins. Hence, it should be recommended to persons with nutritional deficiencies as it is cheap and available all year round.
... Hlízky šáchoru jedlého obsahují sacharidy (cca 44 %), mastné kyseliny (cca 25 %), bílkoviny (5 %), vlákninu (9 %), minerály (draslík, fosfor, vápník) a vitaminy E a C. Ze sekundárních metabolitů jsou zastoupeny flavonoidy, steroly, alkaloidy, saponiny a taniny. Obsah alkaloidů se snižuje pražením (13,6,7,14). Olej lisovaný z hlízek šáchoru jedlého se skládá převážně z mastných kyselin, v největším množství je zastoupena kyselina olejová (67-73 %), v menším pak linolová, palmitová a stearová. ...
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Sedges (Cyperus L.) are annual or perennial herbs of the Cyperaceae family. The genus includes about 600 species, including edible and medicinal species. Cyperus esculentus is an edible and medicinal plant, widely used for its numerous health-promoting effects, including alleviating the symptoms associated with neurological disorders. Cyperus rotundus is also widely used in traditional medicine as a nerve tonic and sedative. Several bioactive substances (for example phenolic acids, phenylpropanoids, terpenes and especially flavonoids) have been found in the rhizome extracts of these plants. These can act as modulators of immune cell function, against inflammation and oxidative stress, but also have significant neuroprotective effects, such as neurogenesis and neuronal regeneration, which lead to improved learning and memory performance.
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Natural fibres have gained huge attention of researchers in the field of composite manufacturing due to its low cost, biodegradability, availability and high performance. However, due to its high hydroxyl content of cellulose, natural fibre is susceptible to water absorption which invariably adversely affects properties of the composite. Researchers have proved that nano-materials such as nanoclay mixed with the polymer composites can overcome the problem. This study investigates tensile strength and microstructural property of tigernut fibres reinforced polymer composites tailored to automotive application. Tigernut fibres mixed with nanoclay of size 50≤µm, were used to reinforce epoxy in three levels of loading 2, 4, 6 % respectively. The composite was prepared by shear mixing of polymer and the reinforcements, followed by lamination and curing of the composite. The tensile strength and microstructural property of the composites produced were examined. The results show that tensile strength increases as the percentage weight fraction of the reinforcement increases. The microstructures show good interfacial adhesion between reinforcement and polymer matrix. Tigernut fibre show a sustainable material useful for automotive applications.
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Twenty four weaner rabbits of 6-8 weeks of age and averaging 550 g in weight were divided into four groups of six (6) rabbits per group and used in a 60 - day feeding trial for blood chemistry and haematological studies. The rabbits were fed raw or processed pigeon pea seed based diets in a Completely Randomized Design. Diet A contained raw (control), Diet B boiled, Diet C toasted and Diet D soaked pigeon pea seed meal (PSM) incorporated at 20% level in weaner rations. The haematological parameters investigated were haemoglobin (Hb), packed cell volume (PCV), white blood cell (WBC), neutrophil (N), lymphocyte (L) and eosinophil (E), while the biochemical components were urea, serum creatinine, bilirubin (total and conjugated), total protein, globulin, serum glutamic transaminase (SGPT) and serum glutamic oxalo acetic transaminase (SGOT). Results showed that white blood cells, lymphocytes, globulin and PCV values were influenced (P0.05) for all groups. Not affected (P>0.05) by diets were blood urea, creatinine, bilirubin, total protein, SGOT and SGPT concentrations. Most haematological and biochemical values obtained were out of normal range for rabbits. Raw or processed pigeon pea did not support remarkable changes in haematological and biochemical profile for weaner rabbits at 20% dietary level of inclusion.
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Milk of tiger nut (A), coconut (B) and soybean (C) were evaluated for their nutritional quality potentials and for possible inclusion in the preparation of various confectionary products. The milk were analyzed for the total solids, pH, protein, fat, titrable acidity, calcium and phosphorus contents. The results revealed a crude protein content of 8.07, 7.87 and 8.90% for the milk of tiger-nut, coconut and soybean respectively. The fat content was highest in coconut milk and tiger-nut while soymilk had the least. The dry matter was highest for coconut milk while soymilk and tiger-nut milk had similar (P > 0.05) percentage. The calcium content was 8.75% (A), 3.01% (B) and 9.25% (C). The phosphorus was greatest for C followed closely by A and the least for B. The total energy (k.cal 100-1g) was estimated as 388.30 (A), 332 (B) and 100.52 (C). The study also revealed highest oleic acid (68.83%) in tiger-nut while lauric acid and capric acids were highest in coconut milk compared with other sources. It was concluded that all the milk samples are potentially good source of dietary protein and energy supplement for human consumption.
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Yellow variety of tiger nut used was obtained from Sabo market, in Ogbomoso, Nigeria The nuts were cleaned, sorted, washed, and were soaked in water and left to ferment for 24, 48 and 72 h respectively. The nuts were drained, dried in an oven and ground into flour. The flour samples were passed through a 45 m mesh size sieve. The flour was analyzed for proximate composition and some functional properties. There were changes in some constituents of the flour with fermentation time. There was an increase in protein content (7.73 -9.23%) and reduction in fat content, likewise with the ash, and starch content. There was also an increase in the sugar content over the fermentation time (7.31 -9.69%). For the functional properties, 0.56 -0.62 g/ml were recorded for loose bulk density, within the fermentation time of 24 – 72 h. For packed bulk density 0.83 -0.91 g/ml were recorded, 123 – 141 g/100 g for water absorption, 67.6 -71.3 g/ml for oil absorption capacity within the fermentation time of 24 -72 h. Changes in the pasting characteristics of the flour samples were also noticed.
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This work was done to ascertain the feasibility of obtaining caramel from malted tubers of Cyperus esculentus. The tubers of C. esculentus were partially germinated for 10 days and sun-dried for 24 h. The sun-dried samples were then kilned at 70°C for 24 h and at 120°C for 5 h for further caramelization. The kilned samples were finely crushed, infused with deionized water at 60°C and the malt extract heated up to 127°C, to give a brown-black syrupy substance, caramel, with specific gravity 38.97±0.77°Bé. Reducing sugars as d-glucose in the unmalted tubers before and additional sugars after hydrolysis for 30 min were 24.75±4.54 and 64.80±2.28 mg/g of sample, and in the green malt 123.13±4.28 and 82.07±4.13 mg/g of sample, respectively.
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A 4-yr field study was conducted to evaluate yellow nutsedge suppression in 'Tifway' bermudagrass. Herbicide programs included preemergence (PRE) applications of metolachlor (3.4 kg ai/ha) and postemergence (POST) applications of imazaquin (0.28 kg ai/ha) plus MSMA (2.2 kg ai/ha) or halosulfuron (0.07 kg ai/ha) plus MSMA (2.2 kg/ha). Herbicides were applied to the same plots each year. Yellow nutsedge shoot suppression and tuber numbers were determined each year. Suppression of yellow nutsedge shoots increased over the 4-yr period from < 74% in 1993 to > 83% by 1996 with two annual applications of imazaquin plus MSMA or halosulfuron plus MSMA. PRE metolachlor applications did not suppress shoot production in any year, nor did they enhance suppression from POST treatments. Sequential applications of halosulfuron plus MSMA and imazaquin plus MSMA increased shoot suppression by 17 to 24% at 3 mo after initial treatment (MAIT) compared to single applications. All treatments reduced tuber numbers (> 60%) after 3 years compared to untreated plots.
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The paper reports the proximate evaluation of dry Cyperus esculentus tubers and the characterization of the oil fraction. The proximate composition was 3.63 ± 0.28, 2.48 ± 0.33, 12.88 ± 0.91, 2.68 ± 0.08, 29.67 ± 0.47 and 52.29 ± 1.46% for moisture, ash, crude fibre, crude protein, oil and carbohydrate, respectively. The quality of the oil extracted by Soxhlet was assessed in terms of acid value, iodine value, saponification value, free fatty acid content, specific gravity, melting point, solidification point and heat of combination. These implicated the oil as a lauric acid-grade oil which was non-acidic, stable, non-drying and of very low unsaturation. The value of the heat of combustion came within range for edible oils and a subzero solidification point qualified it for use in oils and oil products required to remain uniformly liquid at refrigeration temperatures.