OPTIMISATION OF STEEPING AND GERMINATION TIMES ON THE ANTIOXIDANT POTENTIALS OF PIGEON PEA (CAJANUS CAJAN)

In an attempt to maximize the antioxidant potentials of pigeon peas, the effect of steeping and germination times on the antioxidant content and radical scavenging activities of pigeon pea was investigated using response surface methodology. Using the central composite rotatable design (CCRD), pigeon pea seeds were soaked in water (2-28 h) and germinated (9-111 h). Thirteen samples were generated and analyzed for phenols, flavonoids, reducing power, 1, 1, Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power (FRAP). Results revealed that the quadratic effects of both steeping and fermentation times were significant for predicting the phenols, flavonoids, reducing power, and FRAP while only the steeping time had a significant quadratic effect on DPPH. Significant correlation coefficients (r) were found to exist between the antioxidants and most of the antioxidant activities. The optimum steeping and germination times obtained were 15 and 96 hours respectively; predicted values for phenols, flavonoids, reducing power, and FRAP were 50.09 mg/100g, 26.56mg/100 g, 0.75 µg/ml, and 69.30 µmol/g respectively.