2.2 Sample preparation
2.2.1 Preparation of native acha flour
Acha flour was prepared following Ayo et al. (2007) method. Dust and chaff were taken out by winnowing the grains. Residual dust and stones were washed away through sedimentation using large bowls. The cleaned and de-stoned grains were subjected to drying in a cabinet dryer at 45 °C. After drying, the grains underwent milling using an attrition milling machine, and the resulting flour was sieved to achieve a particle size passing through a 50 µm mesh. An airtight container was used to package the acha flour.
2.2.2 Preparation of fermented acha flour
Fermented acha flour was prepared as described by Onweluzo and Nwabugwu (2009). Acha grains were soaked in distilled water and left to ferment for 3 days. Following fermentation, the soaked water was drained, and the seeds were dried in a cabinet dryer for 24 h at 40 °C. Subsequently, the dried grains underwent milling using an attrition milling machine, and the resulting flour was sifted to achieve a particle size passing through a 500 µm mesh.
2.2.3 Preparation of acha cookies
About 100% acha -based cookies was prepared and baked as described by Okpala et al. (2011). The formulation comprised of 200 g of acha flour (native flour, fermented four, malted flour) 2 g of salt, 2 g of baking powder, 62 g of egg, 80 g of margarine, 50 g of sugar, 15.6 g of milk and 10 ml of vanilla flavor. Margarine and sugar were blended to uniformity with an electric mixer operating at a medium speed for 5 min. Eggs and milk were incorporated into the mixture and mixed for duration of 30 min. Additional ingredients, including flour, salt, vanilla flavor, and baking powder, were thoroughly blended to make the dough. The dough was kneaded to achieve a consistent thickness of 0.5 cm, and then circular cuts with a diameter of 5 cm were made. The dough was placed in the oven and baked at 150 °C for 30 min, followed by a cooling.
2.3 Functional properties
The water and oil absorption capacities was determined using the method described by Adeyinka et al., (2016). The method explained by Adeleke and Odedeji (2010) was used to determine bulk density. Swelling capacity was determined using the method described by Sobowaleet al . (2021a).
2.4 Pasting Properties
The Rapid Visco Analyzer (RVA) (Techmaster parten N103802 Australia) was used to determine the pasting properties, as reported by Li et al. (2011). After weighing about 3.5 g of the samples into an empty, dry canister, 25 ml of distilled water was poured into it. The solution was well mixed, and the canister was properly placed into the RVA as specified. The slurry was heated to a temperature of 50 and 90oC for 2 min. At a heating rate of 11.25 °C/min, the pasting profile, including final viscosity, peak viscosity, setback, breakdown, pasting temperature, and peak time, was obtained using thermocline for windows software connected to a computer.