Engineering Parameters Responses during Extrusion Processing of Noodles Analogue from Water Yam, Yellow Maize, and African Yam Bean Flour Mixture

This study investigated the effect of extrusion process on engineering properties of noodles analogue from water yam, yellow maize, and African yam bean. Flour blend from water yam, yellow maize, and African yam bean were produced using the standard method of dry milling and was used to extrude noodles analogue using a brabender single screw laboratory extruder (Duisburg DCE 330 model) fitted with 3.0mmdie nozzle diameter. A central composite rotatable design (CCRD) with three variables, namely barrel temperature, feed moisture content and screw speed and five level coded – a, -1, 0, +1,, +a, was used for the study and data was generated at (p<0.05). Results of result of the engineering properties of noodles analogue showed that toque ranged from 22.4 to 60.50Nm/s, mass flow rate ranged from 33.90 to 109g/min-1, specific mechanical energy ranged from 100.19 to 385.97kj/kg, and the residence time ranged from 22 to 55s in this study. The CCRD was effective in explaining the effect of the process conditions on noodles analogue as influenced by barrel temperature, feed moisture content, and screw speed of the extruder. The data obtained from the study could be used for control of product characteristics.It was generally observed that the changing of feed moisture content, barrel temperature, and screw speed influenced an acceptable torque, mass flow rate, and residence time during the extruder operation. The noodles analogue produced at this cheap machine operating conditions could be projected for commercial production.

Functional Properties of Noodles Analogue from Water Yam, Yellow Maize, and African Yam Bean Mixtures – A Response Surface Methodology

Response surface methodology was used to investigate the effect of extrusion process on proximate composition of noodles analogue from water yam, yellow maize, and African yam bean flour mixture. Flour blend from water yam, yellow maize, and African yam bean were produced and was used to extrude noodles analogue using a Brabender single screw laboratory extruder (Duisburg DCE 330 model) fitted with 3.0 mm die nozzle diameter. A central composite rotatable design (CCRD) with three variables, namely barrel temperature, feed moisture content and screw speed and five level coded – a, -1, 0, +1, +a, was used and data analyzed by regression analysis. Results showed that bulk density ranged from 0.41 to 0.09 g/cm water solubility index ranged from 4.41 to 6.36%; water absorption capacity ranged from 2.05 to 5.66% and expansion ratio ranged from 1.62 to 3.81respectively. The coefficients of determinations (R2) were high and ranged from 0.9039 to 0.9887 at 5% level. The response surface plots suggested that the models developed had a good fit and the CCRD was effective in explaining the effect of the process conditions on noodles analogue as influenced by barrel temperature, feed moisture content, and screw speed of the extruder. The data obtained from the study could be used for control of product characteristics. The study indicated that improved noodles analogue from available and cheap roots, cereal and legumes such as water yam, yellow maize, and African yam bean can be produced for possible projection for the commercial production of noodles analogue.

Nutritional Composition of Flour Blends from Water Yam, Yellow Maize and African Yam Bean

Adequate and proper understanding of the nutritional composition of different flour materials is important in their use in the production of baked food materials. The proximate composition of water yam-yellow maize and African yam bean flour mixtures was therefore evaluated in this study. Standard procedure for dry-milling unit operation was used in the flour processing. Flour samples were blended in different ratios to form the following composite samples: AFK which comprised of 30% water yam (WY):40% yellow maize (YM):30% African yam bean (AYB); BGL which comprised of 40WY:30%YM:30%AYB CHM comprising of 50%WY:20%YM:30%AYB; DIN comprising of 60%YM:10%YM:30%AYB and control treatment comprising of 100%WY. Crude protein content ranged from 4 to 22.50%; fat content ranged from 1.80%; ash content ranged from 7.00%; moisture content ranged from 6.00 to 10.00% carbohydrate content ranged from 50.43 to 80.90% and energy content ranged from 331.50 to 356.35%ked. Addition of yellow maize and African yam bean statistically (p<0.05) increased the protein, fat, fibre, ash, moisture and energy content of flour blend but statistically (P<0.5) reduced the carbohydrate content. Flour sample DIN found to be adequate for both children and adult consumption of the flour when compared to the Codex Alimentarius Commission [1].

Pasting Properties of Flour Blends from Water Yam, Yellow Maize and African Yam Bean Seeds

Pasting properties of flour blends from water yam, yellow maize and African yam bean were investigated in this study. Peak viscosity ranged from 133.50 to 166.25RVU, Trough viscosity ranged from 85.08 to 135.20RVU, break down viscosity ranged from 28.17 to 50.58RVU, final viscosity ranged from 5.05 to 5.49 min and pasting temperature ranged from 80.25 84.15oC. Addition of yellow maize and African yam bean affected (p<0.05) the peak viscosity, trough viscosity, break down viscosity, final viscosity, and setback viscosity in different trends. However, peak time and peak temperature of the flour sample were not statically (p<0.05) affected by the blend ratio in this study. Amongst the flour samples investigated in this study, flour sample DIN (60%WY:10%YM:30%AYB) showed promise for value added products such as noodles among other flour products. They flour sample adjusted to be the best sample could be used as a good replacement for wheat flour and when achieved, it will reduce the cost of importation.