To improve the child nutrition, complementary foods were formulated using the following components:Lactococcus lactis sp. (Lc. lactis sp.) strain, 20% red kidney bean (Phaseolus vulgaris L.), 60% mung bean (Vigna radiate), 10% irish potato (Solanum tuberosum), and 10% ripe fresh papaya (Carica papaya) fruits. The formulation compounds were mixed and then inoculated by different concentrations of the bacterial strain 0 CFU mL -1 (control diet); 1×10 6 CFU mL -1 (Diet 1) and 2×10 6 CFU mL -1 (Diet 2). The effects of bacteria concentrations on pH, final viable cell counts, titratable acidity, Water Holding Capacity (WHC), antioxidant activity, viscosity and proximate composition were investigated. Results showed that diet 2 had the lower pH (4.50), highest final viable cell counts (3.9 × 10 9 CFU mL -1). Bacteria culture increased the WHC and viscosity of diets. The free radical scavenging activity was significantly (p<0.01) higher in diet 2 (57.33 ± 0.66%) when compared to the control diet (31.37 ± 0.25%). Crude protein, fat, total energy and mineral contents increased with starter cultures. The results of this study showed that Lc. lactis sp. strain improved the nutritional value of fermented foods 1 and 2. Diet 2 showed the best results in term of nutritional values, mineral contents and may be recommended as complementary food for children.