الفهرس 
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Abstract
A. Chemical Composition of Mature Cowpea Seeds
The results obtained for chemical analysis for the seeds of two cowpea varieties could be summarized as follows :
1. The protein content in Pusa phalguni (29.25 % ) was higher than that found in Black-eyed pea (2).49 %), while the latter contained a lower level of crude fiber ().50 %) t~an the former (4.54 %).
2. The amount of carbohydrates and undetermined materials was higher (64.14 %) in Black-eyed pea than that estiimated (58.77 %) for Fusa phalguni. Only a slight difference was observed in ash content.
B. Amino Acid Composition of Mature Cowpea Seeds :
The total amino acid analysis of the two varieties of cowpea seeds as follow
1. With the exception of cystine, lysine, phenylalanine, aspartic acid, histidine and serine, considerable difference were observed among the different amino acids in the two varieties.
2. The essential amino acid profile indicated that the seeds of Fusa phalguni contained relatively higher proportions of leucine + isoleucine, methionine and tyrosine than those found in the other variety.
). Among, the non-essential amino acids, the amounts of alanine and arginine were higher, while those of gluutamic acid, and glycine were lower in the Fusa phalguni seeds than in Blac-eyed pea seeds.
4. Deficiencies of sulphur-containing amino acids were reflected in their respective scores of 54.3 and 33.4 for Fusa phalguni and Black-eyed pea.
5. The second limiting amino acid was valine (chemical score,64.6) and lysine (chemical score, 77.5 ) in Fusa phalguni and Black-eyed pea.
1. The quantitative detennination of both total and indiviidual free amino acids in each variety indicated that the Black-eyed pea variety was richer in total essential amino acids except(leucine+isoleucine+threonine) and non-essential amino acids except(alanine,aspartic acid, glycine,and serine)than the Pusa phalguni variety.
2. The total free aromatic amino acids were predominant and accounted for 32.9 and 29 % of the total free amino acids in Black-eyed pea and Pusa phalguni varieties respectively.
1. The salt soluble proteins (globulins) were the major protein component in both varieties but Pusa phalguni seeds contained a higher level of globulins(74.74 %) than that found in Black-eyed pea (72.79 %). The latter variety was characterized by the presence of more albumin (18.81 %) and less gliadin (4.65 %) than the former which contained 14.27 % and 7.69 % albumins and gliadins respectively.
2. Glutelins were found to account for 3.3 and 3.75 % of the total ext~actable proteins of Pusa phalguni and Black-eyed pea respectively.
1. The solubility curves of cowpea total albumins of pH values ranging from 2.12 indicated that the solubility of these proteins at alkaline and acidic pH values
E. Effect of pH on Solubility of Cowpea Albumins and Gloobulins :
was greater than that observed at neutral pH and that there were points of minimum solubility at pH 3.7 and 3.9 for total albumins of Black-eyed pea and Pusa phallguni respectively.
2. The minimum solubility of the globulins, was at pH 4.0 for Black-eyed pea and at pH 4.1 for Pusa phalguni.
Changes in Cowpea Seeds at Various Stages of Maturit~ :
F. Change in Chemical Composition
Results of chemical analysis of the whole seeds at various stages of development on a dry matter basis indiicated that :
1. The crude protein of the seeds of Black-eyed pea decreased during the early stuges of seed development followed by slight decline during the period between the 21st day
and 28th day after anthesis. In Fusa phalguni seeds,
the crude protein content increased temporatily during
the very early staSe of development to reach its maximum level by the 141£ day after anthesis, then decreased gradually to its minimum level by the 28th day after anthesis.
2. The carbohydrate and undetermined material at different stages of development showed on opposite trend to that
for crude protein. The results on fresh weight basis, however, present a different picture.
J. Agradual increase in the fiber content was observed during the seed development, followed by a sharp inncrease when the seed reached full maturity.
4. The change in the ash content in the seeds of the two varieties followed the same trend, showing an increase during the early stage of development, followed by
a decrease in the next st&ge.
G- Change in Free Amino Acid Content :
At various stages of seed development, sixteen free amino acids were detected in different amounts in both varieties. The results of amino acid analysis are presennted on a dry matter basis and fresh weight basis :
1. A sharp decline in the total free amino acids was obserrved during the early stages of seed development between the 71£ and 21th day after anthesis in both varieties, followed by slight decrease between the 21 th and 28th day from anthesis in Black-eyed pea seeds.
2. Lysine and leucine + isoleucine were the most abundant essential amino acids in Black-eyed pea and Pusa phalguni respectively.
3. Amounts of aspartic acid and serine were increasing temporarily from their initial values in Black-eyed pea seeds. Histidine, arginine, glycine and alanine were declining between the 7th and 21th day after anthesis.
H- Change in Total Amino Acid Content During Seed Developpment :
The results of amino acid analysis for the cowpea seeds collected at various stages of seed development as followed :
1. A slight decrease in total essential and non-essential amino acid was observed during the early stage of Blackkeyed pea seed development, followed by a sharp decline between the 14th and 21~ day after anthesis and a
small increase as the seed neared full maturity.
2. In Pusa phalguni seed an initial rise during the early stage was evident. The values then declined as developpment progressed up to the 28 th day after anthesis but
a small rise was noticed when the seed reached full ripening.
3. The changes in proline and serine levels followed the same trend in Black-eyed pea, but this was not the case in Pusa phalguni.
4. The results of amino acid analysis calculated on a fresh weight basis, present a different picture. The
acids remained without any large changes during the period between 7th and 21st day of development followed by increases during the last stages of maturity.
5. In Pusa, phalguni seeds, valine (chemical score, 57.4) was the first limiting amino acid and threonine(chemical score 91.5 ) was the second limiting amino acid in sampples collected on the 7th day after anthesis. These two amino acids were limiting in seeds collected on the 141£ day. The chemical scores for the sulphur-containing amino acids were 91.4, 81.7 and 62.6 % in the samples
of 14 th, 21 st and 28 th day after anthesis.
2. The molecular weight was determined to be 153000,100000, 56000 and 18000 for components A, B, C, and D respectiively.
3. The spectrophotometric analyses were used for characterrizing the albumin components.
~. The amino acid composition indicated the presence of higher levels of histidine, proline, and some of the essential amino acids, in albumin component (A) than that usually found in the albumin components.
J- Fractionation and Characterization of Cowpea Seeds Globulins :
1. Fractionation of the total globulins on Sephacryl S-200 column produced two major and one minor compoonents.
2. The molecular weight of the major globulin components were estimated to be greater than 250000 and 178000 for the globulin component (a) and (b) respectively and the latter component was the predominant globulin.
), The two major globulin components were free from contaamination of other proteins as shown by polyacrylamide gel electrophoresis.