The moisture content of the five legume flour samples (Breadfruit, Groundnut, Soybean, Bambara-groundnut and Cowpea). Analyzed was found to be 10.87, 7.66, 7.85, 10.36, 10.44 respectively with breadfruit having the highest value. The samples showed significant difference at (P<0.05). The groundnut flour having lower moisture content can be stored for a longer period than the other legume.
High water moisture content in
flours, predispose them to bacterial and fungal attack. As a result of the
value of the moisture content of soybean flour not being so high, it can also
be stored for a long period of time. The values for groundnut and soybean flour
fell within range (5-8%) given by Yagodin (1984) for legume.
PROTEIN
The protein content in the legume
was 17.45, 25.35, 39.86, 16.64 and 23.36 for breadfruit, groundnut, soybean,
bambara-groundnut and cowpea respectively with soybean having the highest
value.
At P<0.05, there is significant
difference between the legume samples.
This range of values falls within
the range given by Tobin and Carpenter (1978) which is 15-30%. The protein
content of the legume was than those reported by Martin- Cabrejas et al. (1994). Soybean are rich source
of protein. Dietary protein are needed for the synthesis of new cell, repair of
worn out tissues, enzymes, hormones, antibiotics and other substance required
for healthy functioning development of the body and its protection (cheese
Brough, 1987) and for the treatment of protein energy malnutrition (Omoruiyi et al; 1994).
ASH
The ash content of the samples
breadfruit (1.45) groundnut (4.87) soybean (3.56). Bambara groundnut (2.95) and
cowpea (3.78) was observed, to be a little higher compared to results of the
above workers it is however in agreement with the observations of Esenwah and
Ikere Bomeh (2008) and Omafuvbe et al.
(2004) who report higher values. The bio-chemical analysis of seeds of the
legume showed that the ash contents ranged from 1.45 to 4.87g /100g which were
found to be low as compared to those reported by Udayasekhara (1995) but comparable
to those reported by Fasoyiro et al. (2006). Ash content of groundnut and
cowpea was as high as 4.87% and 3.78%, respectively and that of other legumes
ranged between 1% and 3.80%, there were significant difference at P<.0.05.
this range of values obtained falls within the range fiven by Ologhobo and
Fetuga (1988) and Yeshajahu (1991) as 4.1 – 4.77 and 2.8 – 4% respectively.
With these ranges of values, it means that small amount of inorganic compounds
are present in the legume samples.
STARCH AND REDUCING SUGARS
The starch and reducing sugars
contents obtained in this study was low while the dry matter was higher than
those reported. These differences could be attributed to environmental factors,
as well as the cultivars of the different legume seeds and the experimental
procedure used. Reducing sugar levels has been reported to decrease with processing (Omafuvbe, 2004). The
reducing sugar is higher in groundnut and the starch content is higher in
breadfruit seeds. This variation is attributed to the high energy content of
the legume (breadfruit and groundnut).
FIBER
The fibre content of the legume samples analyzed was
found to be 2.44, 3.84, 3.87, 4.93 and 4.02 for breadfruit, groundnut, soybean,
bamabara groundnut and cowpea respectively, with Bambara groundnut having the
highest value. The legume samples
showed significant difference at p<0.05. The fibre content in relation to
the diet is adequate, exerting a major influence on the metabolism of the
gastrointestinal tract (GIT) and constituents its deficiency linked to
appendicitis, biventricular disease and hemorroids (Gibney, 1989). Fibric also
sows down the release of glucose into the blood and decrease intercolonic
pressure, hence, reduces the risk of colon cancer (Gibney, 1989). This range of
values obtained falls below the range reported by Gibney (1989) which is
13-19%.
FAT
The fat content obtained from the analysis of the
regume samples was 7.65, 47.57, 20.42, 5.57 and 2.35 for breadfruit, groundnut,
soybean, Bambara-groundnut and cowpea, respectively with the groundnut flour sample having the highest value,
cowpeas have been shown to be low in fat content (Davidson et al., 1975). At p<0.05, there was significant different
between the legume flour samples, fat provide strong energy and transports fat
soluble vitamins like vitamin A, D, E and K (Ologhobo, 1988).
The range of value for cowpea flour,
obtained falls within the range of 2.01-2.88% reported by Ologhobo and Fetuga
(188). The value for the other legume flour samples are higher than these ranges.
Table 2: Dietary fiber in some legume
seeds.
|
Legumes
|
SDF
|
IDF
|
TDF
|
IDF/SDF
RATIO
|
|
Breadfruit
|
1.66d
|
40.66d
|
42.02c
|
24.32bc
|
|
Groundnut
|
1.87c
|
39.
87e
|
41.73e
|
21.
32a
|
|
Soybean
|
2.06a
|
40.23c
|
42.28a
|
19.53b
|
|
Bambara
groundnut
|
1.95b
|
69.98d
|
41.93d
|
35.89bc
|
|
Cowpea.
|
2.04a
|
40.16d
|
42.20b
|
19.69bc
|
The result on the dietary fibre content of the five
(5) grain legumes are presented in table 2. It is evident that the total detry
fibre (TDF) content of legume seeds varied form 41.73 to 42.28%. soybean was
the richest source of fibre, followed by cowpea, bread fruit, Bambara groundnut,
and groundnut. Soybean seeds also contained the highest amount of soluble fibre
(2.06) among the other legumes. The legumes were not good sources of soluble
fibre as they do not contained about 5%
SDF commonly found in legume seeds. The TDF content of cowpea as found in this
study do not agrees to that and Swanson
(1989) who reported that cowpea contained 14 to 19% TDF, However, Sharma (1986)
found 17 to 23.4% TDF in cowpea.
The water insoluble to soluble fibre
ratios (Table 1) indicates that all the legumes contained higher proportion of
insoluble fibre than the soluble fibre. This ratio was higher in both Bambara
groundnut and breadfruit, indicated that the fibre of these legumes was mainly
composed of cellulose, constituents of insoluble fibre. The soluble fibre
(pectin and few other non-starch polysccharides). Being viscous gels liner
along the walls of the intestine and thus reduces glucose and cholesterol
absorption into the blood stream (Anderson et
al., 1984 and Toppy et al, 1986).
This helps in dipping low blood sugar and cholesterol levels which is most
beneficial for diabetic and heart patents (Kritchevsky 1986). Since legumes are
better source of soluble fibre than cereals (Hughes and Swanson, 1989). They
are particularly recommended in the diets of both diabectic and heart patient.
Dietary guidelines recommend a
minimum daily intake of DF of 25g (equivalent to 12.5g DF per 1000 calories consumed).
(Martett et al, 2002, USDA, 2000);
which is considerably higher than the estimate instates in western countries
(sungsocho and Dreher, 2001). Public health organization (ADA, 1997).
Recommended that adult should take 25 to 35g dietary fibre per day with adequate
fluid intake. Therefore there is a need to increase fibre intake, which has
prompted the consumption dietary supplements or fibre-enriched food products. Dietary
fibre components like pectins, gum, cellulose and others have been used as
functional ingredients by the food industry, with an extensive market of food
by-products as dietary fibre sources.
Some of the health benefits
associate with a high fibre diet may came the vitamin, minerals or
non-nutritive photochemical present in high fibre foods rather than from the
fibre itself. Some health effects associated with fibre might also be due to
the substitution of high fibre foods for less healthful foods, to the
relatively low fat and calorie levels in most high-firbre diets, or to the
correction between high-fibre diets and other healthful life style choices
(such as regular exercise). In addition comparisons made between population
groups (such as the observations made by Dr. Burkitt) may not be directly
applicable to individuals (Just because societies that eat high-fibre diets
have a low frequency of constipation, for example, it does not necessarily
follow than an increase in fibre intake would relieve constipation in a
specific western individual ). The best accepted beneficial effect of dietary
fibre is relief of constipation (Marlett, 1992). Physicians frequently
recommend a trial of high-fibre diet as a
first step in the treatment of constipation. I adults (Ada, 1993; Gray,
1995) and as treatment for irritable bowel syndrome (A functional gastrointestinal
disorder that may involve constipation and/or diarrhea) (Bennett and Cerda,
1996).
Dietary fibre, in conjunction with
other therapies, is also used to treat chronic constipation in childhood
(Mcclung, 1995, Hillemeier, 1995).