Chemical, Functional and Sensory Properties of Extruded Breakfast Strips Produced from a Blend of Orange-fleshed Sweet Potato, Soybean and Plantain Flour

Abstract

Breakfast strips were produced from different blends of orange-fleshed sweet potato (Ipomea batatas), plantain (Musa paradisiaca) and soybean (Glycine max) flours with substitution ratios of 100:0:0, 90:10:0, 90:0:10, 80:10:10, 70:15:15, 60:20:20 and 50:25:25 and labelled as samples A, B, C, D, E, F and G, respectively. The blends were evaluated for functional properties, total carotene, vitamins (B2 and B6) and sensory properties of the breakfast strips with a commercial breakfast food (Flakes) as control (sample H) . For the functional properties, the water absorption capacity decreased while the oil absorption increased with an increase in substitution levels of the soybean flour. The bulk density, solubility, swelling power and swelling volume were higher in sample A. The least gelation capacity maintained a constant rate of 4% across the blends. The moisture content of the strips ranged from 7.25-9.40%. The Ash contents were below 3% for all the blends. The protein contents increased with an increase in substitution with soybean flour while sample A - breakfast strips from 100% orange-fleshed sweet potato flour showed the highest value for fats (5.62%). The fibre content ranged from 0.69 to 5.14% and carbohydrate content reduced with an increased substitution with soybean flour (72.25-78.70%). The energy value ranged from 351.90-384.80 Kcal/100 g which was within the limit recommended for breakfast foods. Total carotene content increased with increased substitution with orange-fleshed sweet potato (15.18-33.56 mg/kg) which is significantly higher than the control at 0.75 mg/kg. The result of the sensory evaluation showed that the overall acceptability of the samples produced compared favourably with the control. Sample A and B showed a vitamin B2 of 4.70 and 4.00 mg/kg, respectively. However, the values decreased with increase in the addition of soybean while vitamin B6 increased with increase in soybean.