NUTRITIONAL QUALITIES AND STORAGE STABILITY OF READY-TO-USE-THERAPEUTIC-FOOD (RUTF) FROM MAIZE SESAME AND SOYABEANS

Abstract

The study aimed at evaluating the nutritional (proximate, mineral, vitamins, amino acid, and protein quality through rat assay) anti-nutritional properties, antioxidant potential, to determine the acceptability and storage stability of ready-to-use therapeutic foods (RUTF) formulated from maize, sesame and soyabeans. Formulation of three composite flour blends was carried out using Optimal Design Model of Response Surface Methodology. The variables are maize flour (31-55%), sesame seeds flour (25-45%) and defatted soyabeans flour (8-24%); the responses were for proximate composition. The three blends: Runs 1, 6 and 8 with maize, sesame, defatted soyabean flours in ratio 45:47:8, 31:45:24 and 55:25:20 respectively were selected from optimization result to produce three samples of ready- to-use-therapeutic food RUTF1, RUTF6 and RUTF8. The result of the proximate analysis showed that the energy value (536.33-552.94 kcal/100g), the protein content (11.35-14.82%), fat content (49.05-50.94% and the moisture content (1.56-2.21% of the RUTFs samples are all in conformity with standard recommendations for an ideal RUTF. The mineral component was found to vary significantly (p≤0.05) with increasing defatted soya flour and sesame paste in flour blends. The mineral composition of the samples showed that potassium (ranging from 1025.02 to 1138.00 mg/100g), was the predominant mineral followed by calcium (ranging from 328.1 to 476.41 mg/100g), phosphorus (ranging 304.10 from 450.09 mg/100g) and sodium (ranging from 270.1 to 289.5 mg/100g). Other elements found were in comparatively low concentrations. Result of the antioxidant properties of the RUTF samples revealed that RUTF1 displayed the highest DPPH radical scavenging activities of 51.96% which is similar to that of the control. The values of the antinutrients (phytate 0.0519 to 0.838mg/100g, trypsin inhibitor 0.025 to0.315mg/100g and oxalate 1.213 to1.869 mg/100g) were at a safe level. For the vitamin composition RUTF1 showed a comparative highest amount similar to the control. It was observed that the percentage of total essential amino acids (TEAAs) of the formulated samples ranged from 37.77% in RUTF1 to 43.04% in RUTF6 and the values were very close to the control sample (44.16%). The sensory result showed that the formulated samples compare favorably with the imported RUTF sample (control) in flavor, color, aroma and general acceptability, with samples RUTF1 rated next to the control, which had the highest rating. TBA, FFA and total viable count of bacterial, mold increased gradually during storage. Throughout the storage period, coliforms were not seen in the samples, an indication that they are safe for human consumption. The nutritional qualities of the RUTFs were assessed biologically using animal feeding experiment to determine the growth rate, feed intake, protein quality parameters and haematological properties. The protein efficiency ratio (2.34-2.37), biological value (89.13-89.60), true digestibility (86.65-86.91) and net protein utilization (71.53-72.89) of the diets indicated good growth promoting quality of the proteins. The PCV, Hb, and RBC of the rats fed with basal diets were lower than those fed with casein, commercial sample and the locally formulated RUTFs. The white blood cells (WBC) and red blood cells (RBC) of the rats fed/ the formulated diets fell within the normal ranges. RUTF6 exhibited a better growth performance compared to the commercial RUTF and Casein samples. However, sample RUTF1 had the highest overall rating considering all analysis carried out in this study therefore it has the potentials to replace the imported RUTF as therapeutic diet to ameliorate the problem of Protein Energy Malnutrition.