Quality dynamics of maize 'tuwo' (non-fermented maize-based dumpling) as influenced by steaming of maize grits at different resident time.

This study was aimed at investigating the influence of starch pregelatinisation of maize flour, through grit steaming, on the quality characteristics of maize tuwo (non-fermented food dumpling). Maize grits were variously steamed, batchwise, for a period of 15, 30, 45 and 60 min respectively from which flour was obtained. The damaged starch value (13.4-16.2 %) of the pregelatinised maize flour increased with an increase in the steaming duration while that from 0-min steaming period was 12.2 %. The water absorption capacity (3.2-3.7 g/g) and oil absorption capacity (2.1-2.5 g/g) of the pregelatinised maize flour increased with an increase in the steaming duration while those from 0-min steaming period were 2.1 g/g and 2.0 g/g respectively. The pasting variables were found to decrease with an increase in the steaming duration include the peak viscosity (80.5-106.1 RVU), breakdown viscosity (17.9-23.1 RVU), final viscosity (102.4-136.8 RVU), setback-I (41.9-56.6 RVU) and setback-II (21.9-35.5 RVU) while those from 0-min steaming period were 108.3, 36.9, 147.4, 76.0 and 39.1 RVU respectively. The colour characteristics of maize flours and tuwo showed that the L*-value of the flours (85.2-88.7) and tuwo (65.1-67.2) decreased with an increase in the steaming duration while those from 0-min steaming period were 90.0 and 67.7 respectively. The rheological properties of maize tuwo showed that the strain at peak, taken as the cohesiveness index of the food product, ranged between 18.0 and 21.7 % while that from 0-min steaming period was 15.4 %. The softness index of the food product also ranged between 17.5 mm and 17.9 mm while that from 0-min steaming period was 17.4 mm. The sensory quality rating of maize tuwo prepared from the pregelatinised flour showed that the food product obtained from the 30-min steaming duration was rated the highest in terms of texture (mouldability), taste and overall acceptability.