Chiemela Enyinnaya Chinma

Effect of germination on the physicochemical and antioxidant characteristics of rice flour from three rice varieties from Nigeria.

This study determined the effect of germination (48 h) on the physicochemical and antioxidant characteristics of rice flour from three rice varieties from Nigeria. Local rice varieties (Jamila, Jeep and Kwandala) were evaluated and compared to an improved variety (MR 219). Physicochemical and antioxidant properties of flours were determined using standard methods. Protein, magnesium, phosphorus, potassium and antioxidant properties of rice flours increased after germination while phytic acid and total starch contents decreased. Foaming capacity and stability of rice flours increased after germination. Germination resulted to changes in pasting and thermal characteristics of rice flours. Germinated rice flours had better physicochemical and antioxidant properties with reduced phytic acid and starch contents compared to MR 219, which can be utilized as functional ingredients in the preparation of rice-based products.

Effects of fermentation time on the functional and pasting properties of defatted Moringa oleifera seed flour

Abstract Effects of fermentation time on the functional and pasting properties of defatted Moringa oleifera seed flour was examined. Moringa seeds were fermented naturally at 0, 12, 24, 48 and 72 h; oven dried at 60°C for 12 h; milled into five different flour samples for each fermentation time and defatted. The functional and pasting properties of the samples were determined. The result shows significant increase in the water absorption capacity, oil absorption capacity, foaming capacity and emulsifying capacity with increase in fermentation time. However, there was a significant decrease in bulk density (0.53–0.32 g/cm3) and dispersibility (36.00–20.50%) with an increase in fermentation time. There were significant increase in peak viscosity, trough, breakdown, final viscosity, and set back with increasing fermentation time. The swelling power and solubility of fermented Moringa seed flour was significantly affected.

Proximate composition, functional, and pasting properties of wheat and groundnut protein concentrate flour blends

Abstract This study investigated the effect of groundnut protein concentrate inclusion on the quality of wheat flour. Wheat and groundnut concentrate flours were blended (%, w/w) at ratios 100:0, 95:5, 90:10, 85:15, and 80:20, with 100% wheat flour serving as the control sample. Subsequently, proximate composition, functional, and pasting properties of blends were determined using established methods. Protein content of the concentrate was 72.80%. Significant (p < .05) increase in protein content of the flour blends was recorded with increasing concentration of groundnut protein concentrate and decreasing concentration of wheat flour. Highest protein content of 28.87% was recorded in blend with 20% groundnut protein concentrate. Fat, ash, and crude fiber contents ranged from 1.93% to 8.84%, 0.70% to 1.13%, and 0.84% to 1.23%, respectively. Carbohydrate decreased significantly (p < .05) with increasing concentration of groundnut protein concentrate. Bulk density and swelling capacity of the flour blends reduced significantly (p < .05) with increasing level of groundnut protein concentrate flour while solubility index, water absorption, emulsion, and foaming capacities increased. Peak time, peak, trough, breakdown, final, and setback viscosities of the flour blends reduced with groundnut protein concentrate inclusion while the pasting temperature reduced. Overall, wheat/groundnut protein concentrate flour blends showed good functional and pasting properties.

Sensory Properties of Extruded Blends of ‘Acha’ and Soybean Flour – A Response Surface Analysis

Blends of ‘acha’ and soybean flours with moisture contents of between 15 and 35% were extruded in a single screw extruder. A response surface design (central composite nearly orthogonal) was used in the investigation with four independent variables comprising of feed moisture content (FMC), feed composition (FC), screw speed (SS) and barrel temperature (TP) combined at 5 levels. The extruded products were subjected to sensory evaluation using a 20-man panelist. The results of the study showed that maximum aroma and colour rating of extrudate blends were observed at high SS with FC playing the determinant factor. Increased feed composition and barrel temperature resulted in decreased texture rating of extrudates. Extrudates of 37.5: 62.5% (soybean: acha) had the highest sensory rating compared to other blend ratios evaluated. This indicated that acceptable extruded blends of ‘acha’ and soybean products could be obtained at 37.5% soybean addition. This is was higher than the 30% already reported in literature for cereal/legume mixes.

Staling of cakes processed from wheat-tigernut ( Cyperus esculentus ) flour blends

Staling of cakes processed from wheat-tigernut flour blends and stored under ambient (29±1 o C) and refrigerated (4±1 o C) conditions was studied. Cake samples were packaged in 5mm thick polyethylene bag and stored under ambient and refrigerated conditions for seven days and six weeks respectively. Staling of cake resulted in increases in chemical properties such as moisture content, water soluble starch, retrogradation and peroxide value resulting in decreases in the sensory properties such as crumb texture and off-flavour development in the cakes. Staling of the cakes was significant under ambient storage conditions after five days and six weeks at refrigerated conditions respectively. Keywords: Wheat-tigernut cake, retrogradation, water soluble starch, peroxide value