Effect of Soaking and Germination on the Functional Properties of Kpaakpa (Hildegardia Barteri) Seed Flour Using Response Surface Methodology

Abstract

Aim: The effects of soaking and germination on the functional properties of the kpaakpa  (H.barteri) seed flour was evaluated. Introduction: Kpaakpa (Hildegardia barteri) plant is a tropical leguminous plant in the family of steruliacea which is grown mostly in semi arid forest with other plants especially in Ivory Coast and Nigeria. The seeds are consumed in West Africa as raw or roasted nuts and have a flavour resembling peanut. Method: The seeds were soaked for 12, 24 and 36 hours and allowed to germinate for 2, 4 and 6 days respectively. The germinated seeds were dried milled into flour and analyzed for functional properties. Results were statistically analyzed and fitted into second order polynomial equation. A face centered response surface method was employed to optimize the process parameters that gave the targeted optimum responses. Results:The functional properties of the flours; bulk density, water absorption capacity and oil absorption capacity, foam capacity and swelling index were in the range of 0.50-0.60, 1.6-2.30 g/ml, 1.68-2.82 g/ml, 4.0-12 %, 1.2-11.respectively.The Water Absorption Capacity and Oil Absorption Capacity of the flour were enhanced by soaking and germination while foam capacity and bulk density decreased. Response optimization showed that soaking time of 12.6646 h with 3.7530 days of germination were derived as the closest process parameters that could give the targeted value of 0.58 for bulk density. Conclusion: Soaking and germination imparted positively to the functionality of the flours with respect to Water absorption capacity and Oil absorption capacity of the flour.