The study of the nutritive value of Cowpea (Vigna ungiculata L.) legume seed is needed, as this legume is a food source in many developing countries. Whole Cowpea Flour (WCF), Dehulled Defatted Cowpea Flour (DDCF), and Cowpea Protein Isolates (CPI) prepared using Isoelectric method (CPII) and using Micellization method (CPIM) are studied. In proximate analysis, the protein content of WCF, DDCF, CPIA and CPIB was found to be 22.3, 26.7, 750 and 76.0 g/100 g, respectively. Net protein value (NPV) was 17.62 for DDCF. Chemical score was 0.66% for DDCF and 112%, 104% for CPII and CPIM, respectively. The first limiting amino acid was cystine for DDCF and threonine for CPII and CPIM. Methionine was found to be the most concentrated essential amino acid in both CPII and CPIM; values were 27.22 and 30.60 g/16 g N, respectively, while lysine was the most abundant essential amino acid in DDCF (4.28 g/16 g N). Essential amino acids of CPIi and CPIM were 22.99 and 15.78 g/16 g N respectively, higher than FAO/WHO reference.

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This study describes the constituents and properties of bitter lupine (BL) (Lupinus termis) and sweet lupine (SL) (Lupinus albus) seed oils in addition to oligosaccharides content in seed flour; each can be beneficial for consumers. There was a significant difference in saponnification number and ester value of both oils. The peroxide value was found (1.80 ± 0.20 meq/kg in BL seed oil compared to 1.89 ± 0.29 meq/kg in SL seed oil. Fatty acids (FA) composition showed that total unsaturated FAs were higher, (88.33 %) in BL seed oil than (87.25 %) in SL seed oil; both values markedly higher than saturated FA content. The major FA in both samples is oleic FA, (50.23 %) in BL and 45.00 % in SL. Essential FAs were found higher (39.80 %) in SL; compared to (36.11) in BL. Total phenols were significantly higher in BL seed oil (58.99 mg/kg); than.SL seed oil (50.95 mg/kg). The oil classes: triglycerides, free FA steroids and alcohols were found higher in SL seed oil; while hydrocarbons, mono-glycerides, di-glycerides and phospholipids were higher in BL seed oil. Total oligosaccharides were found significantly higher (9.74 ± 0.20 g/100 g) in BL flour compared to 8.99 ± 0.10 g/100 g in SL flour; with stachyose in concentrations of 3.9 ± 0.10 g/100 g and 3.88 ± 0.03 g/100 g; respectively.

Anti-nutritional studies on cowpea (Vigna ungiculata L.) seeds as whole cowpea flour (WCF), dehulled cowpea flour (DCF), dehulled defatted cowpea flour (DDCF) and protein isolates obtained from DDCF by isoelectric (CPIA) and micellization (CPIB) precipitation. The protein content of WCF and DDCF were 22.3% and 26.75% respectively, while CPIA and CPIB showed 75% and 76% respectively. The abundant minerals in WCF and DCF were calcium (32.38-33.61 mg/100 g); potassium (29.25-24.99 mg/100 g); and sodium (1.76-1.00 mg/100 g). The least abundant minerals were iron (0.004-0.013 mg/100 g); copper (0.04-0.25 mg/100 g); manganese (0.18-0.30 mg/100 g) and zinc (0.26-1.22 mg/100 g); respectively. Trypsin inhibitor activity for WCF, CPIA and CPIB was found 16,640 TIU/g, 4293 TIU/g and 4290 TIU/g respectively. Condensed tannins in RCF and DDCF were found 0.003% and 0.004% respectively while phytic acid content 0.8% and 1.17% respectively, no phytic acid and tannins were observed in protein isolates. Cowpea flour was also similar to other edible grain legumes in content of anti-nutritional factors; appropriate processing methods improved cowpea nutritive value and significantly reduced the levels of antinutritional factors.

Citation: Khalid II, Elhardallou SB (2015) The Effect of pH on Foaming Properties of Cowpea (Vigna ungiculata L.walp) Flour and Protein Isolates. J Nutr Food Sci 5: 385. AbstractThe effect of pH on foaming properties on cowpea (Vigna ungiculata) seeds as whole cowpea flour (WCF), dehulled cowpea flour (DCF), dehulled defatted cowpea flour (DDCF) and cowpea protein isolates (CPI) obtained from DDCF by isoelectric (CPIA) and micellization (CPIB) precipitation was studied. The protein % was found to be 22.3% in (WCF) and 26% in (DDCF) flour, while 75 and 76% for CPIA and CPIB respectively. The foaming capacity (FC) and foam stability (FS) were greatly affected by pH values. FC of DDCF and CPIB showed minimum level at pH 2.0 while CPIA at pH 4.0. However, the FS of DDCF was highest at pH 5.0 while CPIA and CPIB were less stable. CPIB have poor FS compared to CPIA at all pH ranges (2-12). Maximum FS was observed at pH 9.0 for DDCF which remain stable up to standing period of 2 hr. CPIA form foam with highest initial volume and maximum FS was observed at pH 9.0. FC of all products was found to be higher at alkaline region of pH compared to acidic side. Defattening markedly increase the FC in the flours.