Amino acid composition (AA) and SDS-PAGE Electrophoresis of Flour & Protein Isolates from Two Varieties (DAS & BS) of Nigeria Cultivated Solojo Cowpea [Vigna unguiculata (L.) WALP] (Published)
The amino acid configuration of the protein determines the nutritional value of the protein. Table 1-9 showed the amino acid composition of germinated DAS and BS flour and isolate. The value of the essential amino acid for the flours and isolate was generally highest for Leucine; this was followed by lysine and then phenylalanine. Sprouting was observed to cause increment in the AA quantity of the samples. The lysine content of germinated DAS flour increased from 6.85 to 7.91 g/100 g after 72 h of germination, while that of BS went from 6.97 to 8.20 g/100 g. The Isolates of the two varieties also increased with germination, the isolate of DAS g/100g obtained a value of 6.8 and 6.7 g/100 g respectively for the flour and protein isolate of their cowpea variety. The sulphur containing amino acids too also increased with germination, methionine of germinated DAS flour increased marginally from 0.65 to 0.86 g/100 g, BS flour from 0.65 to 0.91 g/100 g. The isolate of DAS from 1.15 to 1.37 g/100 g and BS isolate from 1.25 to 1.56 g/100 g. The approximate amount of proline, an EAA, was also observed to be apparently increased in germinated peanut cotyledons and sprouts. This goes to show that germination truly improved the AA content of the legumes. The non- essential amino acid had the glutamic acid having the greatest value, followed by aspartic acid, then arginine, while the rest followed at various levels. The non-essential amino acids were also improved by germination. It was also observed that improvement in the AA content of different fractions of the protein isolate from the two (2) varieties of solojo cowpea increased with germination. All the samples had their amino acid quantity reaching and surpassing the FAO/WHO requirement for both children and adult especially after germination except for methionine which is slightly short of the standard after germination furnishing the value of lysine in the range of 5.98-6.05 and isoleucine value in the range of 4.01-4.18. In germination, protein disintegration takes place because the plant makes use of the stored protein as point of supply of nitrogen and carbon for bio –molecule synthesis. Here, lower molecular weight polypeptides were not evident this may likely be due to the higher molecular weight proteins which might have broken down during germination into short chain peptides and amino acid which were not detected by electrophoresis analysis. SDS-PAGE electrophogram confirmed that high molecular weight bands almost disappear after germination of lupin,
Citation: Adeyoju O.A., Adebowale K.O., Olu-Owolabi B.I.,Chibudike H.O., and Chibudike C.E. (2022) Amino acid composition (AA) and SDS-PAGE Electrophoresis of Flour & Protein Isolates from Two Varieties (DAS & BS) of Nigeria Cultivated Solojo Cowpea [Vigna unguiculata (L.) WALP], European Journal of Food Science and Technology, Vol.10, No.4, pp.24-38
Keywords: BS, DAS, Functional, Nutritional, Solojo Cowpea, Under-utilised legumes, Vigna unguiculata, protein isolate