Production and Evaluation of Breakfast Cereals from Rice, African Yam-bean and Orange-fleshed Sweet Potato

Abstract

Aims: The aim was to produce of ready-to-eat breakfast cereals from blends of local rice (Oryza sativa), malted African yam-bean and orange- fleshed sweet potato [Ipomoea batatas (L) Lam.] (umusco/3 variety) flours as well as to evaluate the nutritional properties, microbiological quality and sensory attribute of the formulated breakfast cereals. Study Design: The experimental design that was used is Completely Randomized Design. Place and Duration of Study: The study took place at the Department of Food Science and Technology, University of Nigeria, Nsukka between December 2016 and September 2017. Methodology: The study investigated the application of local rice, malted African yam bean and orange-fleshed sweet potato flour to develop ready-to-eat breakfast cereals rich in proteins and pro-vitamin A. The local rice and malted African yam bean flours were blended in the ratio of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 to produce ready-to eat breakfast cereals which was subjected to sensory evaluation to isolate the best blend (90:10). From the preliminary study, composite flour was formulated by mixing rice flour and African yam bean flour from the best blend in different percentages. Samples of ready-to-eat breakfast cereals were formulated by mixing composite flour (rice and African yam bean best flour blend) with graded levels of orange fleshed sweet potato and 100% rice flour was used as the control sample. The breakfast cereal products were subjected to proximate, pro-vitamin A, microbiological and sensory analysis using standard methods. Results: The protein, ash, fiber and moisture contents of the blends (rice/African yam bean best blend +orange-fleshed sweet potato flours) were significantly (p<0.05) higher than the control but their carbohydrate content were lower than the control. The protein content, fat, ash, crude fiber, moisture, and carbohydrate contents ranged from 6.82(100% rice flour) to 11.21%(90% rice/African yam bean best blend+ 10% orange-fleshed sweet potato flour), 0.20(50% rice/African yam bean best blend+ 50% orange-fleshed sweet potato flour) to 1.21%(90% rice/African yam bean best blend+ 10% orange-fleshed sweet potato flour), 4.03(100% rice flour) to 15.81% (50% rice/African yam bean best blend+ 50% orange-fleshed sweet potato flour), 1.31(100% rice flour) to 2.80% (50% rice/African yam bean best blend+ 50% orange-fleshed sweet potato flour), 6.61(100% rice flour) to 10.92% (50% rice/African yam bean best blend+ 50% orange-fleshed sweet potato flour) and 63.07(50% rice/African yam bean best blend+ 50% orange-fleshed sweet potato flour) to 80.22% (100% rice flour) respectively. The pro-vitamin content of the samples ranged from 0.13 (100% rice flour) to 2.55 mg/100 g (50% rice/African yam bean best blend+ 50% orange-fleshed sweet potato flour). There was an increase in the pro-vitamin A content as the ratio of orange-fleshed sweet potato increased in the blend. The total viable count ranged from 3.0 × 103 to 6.7 × 103cfu/g while mould was not detected in any of the samples. The microbial content of the samples were satisfactory and not high when assessed using the guideline for microbiological quality of cereal products. The sensory evaluation conducted showed that among the six ready-to-eat breakfast cereals, 100% adani rice breakfast cereals, samples RAYBF1+OPF1 and RAYBF5+OPF5 were highly accepted. Conclusion: The study has shown that acceptable ready-to-eat breakfast cereals could be produced from blends of Adani rice, malted African yam bean and orange flesh sweet potato flour. Among the different breakfast cereals, 100% adani rice and sample RAYBF1+OPF1 (90 % best blend + 10% orange flesh sweet potato flour) were highly accepted.