Application of response surface methodology for studying the product characteristics of extruded rice-cowpea-groundnut...

Application of response surface methodology for studying the product characteristics of extruded rice-cowpea-groundnut...

Samuel Sefa-Dedeh, Emmanuel Ohene Afoakwa

Response surface methodology (with central composite rotatable design for k0/3) was used to investigate the product properties of extruded riceÁ/cowpeaÁ/groundnut blends in a single screw extruder. The combined effect of cowpea (0Á/20%), groundnut (0Á/10%), and feed moisture (14Á/48%) levels were used for formulation of the products. The product moisture, expansion ratio, bulk density and total colour change were studied using standard analytical methods. Well-expanded riceÁ/legume blend extrudates of less bulk density and lower moisture content were produced at low feed moisture. Increasing legume addition affected the various shades of colour in the product. Models developed for the indices gave R2 values ranging from 52.8%(for the b-value) to 86.5%(for bulk density). The models developed suggested that the optimal process variables for the production of a puffed snack with an enhanced nutrition and spongy structure from a riceÁ/cowpeaÁ/groundnut blend are low feed moisture of 14Á/20% and maximum additions of 20% cowpea and 10% groundnut. A lack-of-fit test showed no significance, indicating that the models adequately fitted the data.

2004

https://scholar.google.com/citations?view_op=view_citation&hl=en&user=EZuX1N8AAAAJ&cstart=200&pagesize=100&citation_for_view=EZuX1N8AAAAJ:irE4lMk4wWMC

English