Evaluation of suitability of commercially available maize grains for 'tuwo' production in Nigeria

Abstract

This study evaluated the physical characteristics of grains from five different maize varieties [that is, TZL Comp.3C2, TZL Comp.4C2, DMR-ESR-W, DMR-LSR-W and a market sample (Shagari variety)]. In addition, physicochemical properties of their flours, textural and sensory characteristics of tuwo (a maize-based non-fermented food dumpling) prepared from such flours were also evaluated. There were significant (p < 0.05) differences in the amylose content, kernel weight, length, width and depth of the maize varieties and their values ranged from 18.3 - 22.7%, 223.7 - 284.2 g/1000 kernels, 9.1 - 11.9, 8.1 - 9.5 and 3.6 - 4.8 mm respectively. The damaged starch value of flours ranged from 11.3-13.9% while the pasting temperature, peak viscosity, breakdown viscosity, final viscosity, setback-1 and setback-2 ranged from 73.8-76.3°C, 108.1-150.1 RVU, 18.4 - 36.9 RVU, 147.4 - 212.3 RVU, 39.2 - 93.7 RVU and 20.8 - 68.8 RVU respectively; with significant differences at p<0.05. The lightness indexes (L*-values) of maize flour and tuwo ranged from 88.6 - 90.0 and 66.3 - 68.0, respectively while the colour intensity (chroma) of maize flour and tuwo also ranged from 14.7-15.3 and 8.8 - 9.4, respectively; with significant differences at p<0.05. There were significant (p<0.05) differences in the cohesiveness indexes (13.6 - 15.4%) and softness indexes (16.5 - 17.4 mm) of the food dumpling obtained from the maize varieties. Maize tuwo prepared from DMR-LSR-W was rated highest in terms of all the sensory factors [that is, colour, texture (hand-mouldability), aroma, taste and overall acceptability. Both positive and negative correlations existed among some properties of kernel, flour and tuwo from different maize varieties. Key words: Food dumpling, maize tuwo, commercial maize, suitability.