Nutritional Characteristics of Rice (Oryza sativa L.) Composite Flours Obtained by Food Fortification

Abstract

High prevalence of protein-energy malnutrition among the vulnerable population, especially children has prompted research on fortification of common staple cereal foods such as rice. However, rice has inferior nutritional value compared to other popular cereals, such as maize, therefore limiting its full utilization. Its storage protein, glutelins, is not easily digested by monogastric animals; therefore, food to food fortification of rice flours provides protein nutritional compensation as well as improvement of other nutrients. This study was carried out to determine the proximate and mineral (Fe, Zn, Mg, Ca, P) composition of rice composite flours. Methodology: The blending ratios (rice: maize: sorghum: pumpkin: carrots: baobab: amaranth) used in the study were 70:0:0:7.5:7.5:5:10 (AT1), 45.5:24.5:0:7.5:7.5:5:10 (AT2), 35:35:0:7.5:7.5:5:10 (AT3), 23.3:23.3:23.3:7.5:7.5:5:10 (AT4) and 100% rice flour (AT5). Proximate analyses were performed according to Association of Official Analytical Chemist (AOAC) methods. Atomic absorption spectroscopy was used to determine the minerals. Data analysis was done using Analysis of Variance (ANOVA). Mean comparisons for treatments were done using Bonferroni tests and significance level was set at P≤0.05. Findings: Moisture content of the composite flours ranged from 10.87 to12.55% and was significantly different (p<0.05). Ash content was not significantly different (p<0.05) and ranged between 1.08 and 1.85%. The fat content ranged between 5.38 and 10.67%; with AT4 having the highest and AT5 having the least fat content. The carbohydrate content was significantly (p<0.05) different among the flour; ranging between 66.65 and 73.51%. Crude fibre ranged between 1.42 and -2.20%, whereas the protein content ranged from 6.88 to 7.73%. Iron content ranged between 0.06 and 0.08 mg/100g zinc ranged from 0.19 to 0.56 mg/100g. The phosphorus content ranged from 0.07 to 0.18 mg/100g with no significant (p<0.05) difference. The calcium content was significantly (p<0.05) different among the flours and ranged from 1.41 to 1.91 mg/100g. Conclusion: The results show that the flour composites have the potential to improve nutritional status of consumers. Thus, consumption of AT1, AT4 and AT5 composite flours with a protein content of 7.3%, 7.7% and 7.4% maybe recommended for children aged 6 - 59 months in order to prevent protein-energy malnutrition.