TITLE:
Development of a Protein-Rich Ready-to-Eat Extruded Snack from a Composite Blend of Rice, Sorghum and Soybean Flour
AUTHORS:
Mary Omwamba, Symon M. Mahungu
KEYWORDS:
Rice, Sorghum, Soybean, Extrusion, Response Surface Methodology, Snacks
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.5 No.14,
August
6,
2014
ABSTRACT: Extrusion cooking
is an ideal method for the manufacture ready-to-eat snacks. The benefits include
increased protein and starch digestibility in protein-enriched cereal snack
products. Extrusion cooking needs to be controlled if product quality is to be
maintained. Extrusion cooking was carried out at barrel temperature of 110°C - 150°C,
screw speed of 350 - 450 rpm, and feed moisture of 12% - 14% to investigate the
effect of extrusion conditions on physical properties (expansion ratio and bulk
density) of a rice, sorghum and soy flour blend. From response surface
analysis, expansion ratio and bulk density were found to be significantly (P
0.05) effect. Expansion ratio and bulk density
ranged from 2.0 to 2.6 and 0.79 to 0.95 g/ml respectively. One hundred grams of
the extruded product would supply 45% of the recommended daily allowance for
protein in children aged up to 12 years. The mineral content in 100 g
extrudates was found to be 52 mg calcium, 3.01 mg iron and 1.23 mg zinc. The
retention of amino acids in the extruded products was 88% - 95% with lysine—a
limiting amino acid in cereals having a loss of 9.1% after extrusion. Extrusion
conditions can be optimized to produce ready-to-eat snack products with high
expansion ratio, low bulk density and a good nutritional profile to meet the
growing consumer needs for nutritious ready-to-eat snack products.