To develop instant high protein porridge, various ratios of sorghum and cowpeas were extruded at 130 and 165 degrees C and a water content of 200 g/kg using a thin-screw extruder. An increased proportion of cowpeas resulted in an increase in protein content, nitrogen solubility index (NSI), yellow colour, water absorption (WAI) and solubility (WSI) indexes and in a decrease in total starch (TS), enzyme-susceptible starch (ESS), expansion ratio (ER), and porridge firmness. The higher extrusion temperature gave lower NSI, TS and WAI, ESS, ER and WSI increased with severity of heat treatment. The composite of 50% sorghum and 50% cowpeas extruded at 130 degrees C was the most similar to a commercial instant maize-soya composite porridge in terms of composition and functional properties. A serving of 100g would contribute 28% of the recommended dietary allowance (RDA) for protein. This represents a 110% increase in the protein RDA compared to sorghum only.
Reference:
Pelembe, LAM, Erasmus, C and Taylor, JRN. 2002. Development of a protein-rich composite sorghum-cowpea instant porridge by extrusion cooking process. Lebensmittel - Wissenschaft und Technologie, vol. 35(2), pp 120-127
Pelembe, L., Erasmus, C., & Taylor, J. (2002). Development of a protein-rich composite sorghum-cowpea instant porridge by extrusion cooking process. http://hdl.handle.net/10204/2039
Pelembe, LAM, C Erasmus, and JRN Taylor "Development of a protein-rich composite sorghum-cowpea instant porridge by extrusion cooking process." (2002) http://hdl.handle.net/10204/2039
Pelembe L, Erasmus C, Taylor J. Development of a protein-rich composite sorghum-cowpea instant porridge by extrusion cooking process. 2002; http://hdl.handle.net/10204/2039.