African Journal of
Food Science

  • Abbreviation: Afr. J. Food Sci.
  • Language: English
  • ISSN: 1996-0794
  • DOI: 10.5897/AJFS
  • Start Year: 2007
  • Published Articles: 763

Full Length Research Paper

Evaluation of Impact of some extrusion process variables on chemical, functional and sensory properties of complimentary food from blends of finger millet, soybean and carrot

Boru Asefa
  • Boru Asefa
  • Department of Food Technology and Process Engineering, College of Engineering and Technology, Wollega University, Ethiopia.
  • Google Scholar
Eneyew Tadese Melaku
  • Eneyew Tadese Melaku
  • Addis Ababa Science and Technology University, Ethiopia.
  • Google Scholar


  •  Received: 27 April 2017
  •  Accepted: 24 July 2017
  •  Published: 30 September 2017

Abstract

Complimentary food is other food in addition to breast milk. The objective of this work was to evaluate the impact of extrusion cooking screw speed (300, 350 and 400 rpm) and barrel temperature (150, 160, and 170°C) variation on chemical, functional and sensory values of complimentary food made of finger millet in soy bean ratio of 80, 85 and 90% and carrot juice. The incorporation of carrot juice was realized through inbuilt piston type pump to the extruder barrel to maintain the dough moisture at 18% throughout the extrusion process. Proximate compositions were analysed following AOAC procedures. Crude protein was 12.295, 11.623 and 9.984%, oil was 4.927, 3.278 and 3.25%, and carbohydrate was 69.53, 72.14 and 72.98% for the blend ratios of 80, 85 and 90%, respectively, and they were significantly (P<0.01) different with blend ratio variation. Beta-carotene content of the extrudates did not significantly change with extrusion process parameters. The functional properties (water solubility and water absorption indexes) were significantly influenced by barrel temperature and blend ratio (P<0.05). The sensory evaluation of the selected extrudate was performed in seven hedonic scale on quality attributes of aroma, taste, mouth feel, color and overall acceptability. The gruel extruded from 85% finger millet and 15% soybean flour blend, extruded at 150ºC barrel temperature and 350 rpm screw speed was selected with superior organoleptic quality.

Key words: Complimentary food, carrot, finger millet, soybean, extrusion cooking, functional properties.