| dc.description.abstract | The chemical composition of four types of beans
(E.. Vulgaris) Viz: (·1\'Jetz'iioja,Cana dian \lander, j·iexican142
and Rose coco; cow peas (y. Unguiculata) and pigeon peas
(f.. Cajan) was studied by chemical analysis for amino
acids, proximate composition, minerals, gross energy,
trypsin inhibitor and phytohemagglutinin activities. The
amino acid contents of the legumes were compared with that
of FAO/WHO (1973) according to the essential amino acid
Index and chemical score methods. All the legume seeds
studied were deficient in the sulphur containing amino acids
except pigeon pea It/hcih was defi cient in val ine. Tryptophan
was not analysed for.
In the extracts of raw Rose coco, iljvJezi 1,10ja,r'iexican
142, Canadian Wonder beans, pigeon pea and cow pea, activities
of hemagglutinins whi ch was shown to be a protein material
precipitable by saturation with ammonium sulphate (NH4)2S04
were detected at levels of 17066.7, 952.6~ 213.30, 114.0,
9.8, and 2.5 HA/ml respectively. This material was completely
destroyed at l2loC for 30 minutes. Trypsin inhibitor
activities were also ~etected in the extracts of raw Rose
coco, Mexican 142, Canadian Wonder, Mwezi Moja beans Cow
peas and Pigeon peas at levels of 45.1,34.6,24.8,24.3,21.7,
12.8 TUI/ml respectively. However, it was partially destroyed
at l2loC for 30 minutes and the percentage destruction of the
TIA in Mexican 142, Mwezi Moja, Rose coco, Cow pea and Pigeon
pea were 76%, 71, 65, 55, 54, and l~ respe~tlvely.
Pigeon peas and Cow peas were relatively non-toxic
in the raw state and were little affected by heat treatment.
,Addition of tryptophan to autoclaved pigeon peas did not
significantly improve the PER. However, supplementing cow
peas with methionine improved its nutritional value and PER
from 0.4 to 2.4 which was as good (P > 0.01) as casein.
Pigeon peas and cow peas also caused panceatic hypertrophy
when fed to rats. The various cow pea meals when fed to
pigs were not significantly improved by heat and methionine
supplementation.
Histopathological alterations caused by the various
legume diets on some organs of the rats were also monitored.
Generally, the PIIA and TIA induced severe congestion,
haemorhage and coagulative necrosis of the liver. The kidney
was characterized with pyknotic nuclei in the epithelium and
in the pancreas, there was marked pancreatic acinar atrophy.
These experiments showed that raw beans when fed as
the sole source of protein are toxic to rats. The deleterious
effects of raw beans were partially destroyed by heating.
The supplementation of autoclaved beans with DL-methionine
improved performance suggesting this amino acid to be limiting.
Raw and cooked pigeon peas failed to support good growth of
rats even after tryptophan deficiency was corrected. The
nutritional value of cow peas, when properly processed and
supplemented with methionine, is much higher than the
nutritional value of beans and pigeon peas and is almost as
good as that of casein.
The nutritive values of the legumes were determined
with weanling male rats using growth rate. protein efficiency
ratio, feed efficiency and apparent protein digestibility
methods in the diets containing 10% protein supplied wholly
by the appropri ate 1egume. Three different diets were gi ven
to rats; raw legumes soaked and autoclaved legume and
soaked, autoclaved legumes supplemented with the first
limiting amino acid. The control groups had a standard diet
with casein as the protein source. Only cow pea supplemented
with maize to supply 16% protein level was fed to growing
pigs from average weight of 23 kg to 45 kg live weight.
They were fed raw and autoclaved cow peas with or without
0.1 % methionine supplementation. The control group had a
comnerci a1 sow and weaner-di et.
The diets prepared with ground raw b~ans were highly
toxic when fed to rats and caused rapid loss of weight, weakness,
shivering, prostration, anorexia, marked abdominal
distention, fierceness, growth inhibition, debilitation,
emaciation, diarrhea and death within 4-10 days. Autoc1aving
the beans destroyed the injurious effect although there was
still severe growth depression. Addition of 0.3 % O-L
methionine to Mexican 142; Mwezi Moja, Canadian Wonder and
Rose coco beans significantly enhanced the growth performance
of rats and increased the PER from 0 to 1.6, 1.4, 1.3 and
1.2 respectively. They were all inferior (P < 0.01) to
the casein diet which produced a PER of 2.5 when fed to rats | en |
