Effect of Boiling, Pressure Cooking and Germination on the Nutrient and Antinutrients Content of Cowpea (Vigna unguiculata)

The study was conducted to investigate the effect of boiling, pressure cooking and germination on the proximate, nutrients, amino acids and anti - nutrients content of cowpea (Vignaunguiculata). The results showed that the germinated cowpeas (GMC) had the highest value of crude protein (22.89%), crude fat (3.81%) and crude fiber (2.10%) followed by raw cowpeas (RWC) and pressure cooked cowpeas (PCC) while boiled cowpeas (BDC) h ad the least. There was comparable value of ash content in all the samples except for BDC with the least. Boiling had significantly higher moisture content than others. The carbohydrate value ranged from 57.21 to 58.13% for GMC and BDC respectively and 59. 69 to 59.74% for RWC and PCC respectively. Comparable calorific value of GMC and BDC was significantly higher than that of PCC and RWC. The decreasing order of anti - nutrient factors in treated cowpeas is: GMC > RWC > PCC > BDC. This result inferred that bo iling is an adequate processing for drastic reduction of the anti - nutrient factors (phytate, tannin, Trypsin inhibitor and total phenol) in cowpeas. Germination increased the amount of Methionine, lysine and tryptophan by 10.94%, 18.89% and 20.90% respecti vely, while the pressure cooking and boiling caused mild losses of Methionine, lysine and tryptophan. Similarly, germination had increased the amount of macro elements (0.0036mg/kg for Na , 0.024mg/kg for K, 0.021mg/kg for Ca, 0.037mg/kg for P and 0.022mg/ kg for Mg) while boiling and pressure cooking decreased the amount of these macro elements compared with the raw sample. Heat treatments (boiling and pressure cooking) recorded decreased level of micro elements (Fe, Zn, Cu, Mn) while germination had increa sed the micro elements by 4.66%, 3.78%, 13.85% and 6.38% for Fe, Zn, Cu and Mn respectively. Therefore, it could be concluded that the heat treatments (boiling and pressure cooking) had significantly reduced the anti - nutrient factors in cowpeas but germina tion (sprouting) had excellent nutritional qualities.