Abstract
Sorghum-based flakes were produced alone and with 10 and 50% blends of different wheat flour (75% extraction rate). Sensory, chemical, nutritional, and microbiological evaluation of the flakes were investigated. Panellists (n = 20) rated the sensory characteristics and found no significant difference in overall acceptability between sorghum- and wheat-supplemented sorghum flakes. Wheat supplementation increased protein and total sugar contents but decreased fat, ash, and crude fibre. Mineral composition of the flakes generally showed an abundance in sodium, potassium, magnesium, phosphorus and iron but shortages in calcium and copper. However, the 50% wheat replacement resulted in higher iron but lower phosphorus and zinc contents. The 50% blend increased lysine, histidine, arginine, proline, and glutamic acid but decreased leucine and alanine. In general, Saudi No. 4 wheat flour-supplemented flakes had the best amino acid profile. Chemical scores for all samples were higher than those of most similar commercial breakfast cereals. However, lysine and methionine + cystine were still the limiting amino acids.
Total microbial counts, moulds and yeast counts, total coliforms, and spore-formers were very low or absent in all flakes.