Effect of Storage Conditions (Relative Humidity, Packaging Materials and Time) on the Chemical Properties of Maize-soy Flour Blend

Aims: The aim of this study was to examine the effect of storage conditions on the of maize-soy flour blend.

Study Design: Preliminary studies were conducted using ratio blends of 70:30, 75:25, 80:20, 85:15, 90:10, 95:5 and 100:0 of maize flour to soy flour. This was to ascertain the best blend formulation for the study. The sensory attributes showed that the ratio 85:15 of maize-soy flour blend was preferred. It was packaged in low density polyethylene (LDPE), high density polyethylene (HDPE) and stored at 30.5 ± 3°C with relative humidity of 57% and 82% for 4 months. Analysis of proximate composition, pH, total titratable acidity (TTA), thiobarbuturic acid (TBA) was carried out on the samples at a monthly interval respectively.

Results: Packaging significantly (p > 0.05) affected the chemical qualities of “soy-fermented maize” flour during storage. Moisture content, titratable acidity (TTA) and thiobarbuturic acid (TBA) increased with the storage period (9.46% - 23.5%, 0.12% - 0.21%, and 0.06 - 0.12 respectively) while all other chemical qualities of the soy-fermented maize flour decreased significantly (p > 0.05) (pH: 5.18 - 3.45, protein: 15.21% - 12.18% fat: 7.45% - 5.36%, fibre: 3.27% - 1.65%, ash: 1.12% - 0.89% and carbohydrate: 62.97% - 56.87%.

Conclusion: The samples packaged in HDPE were more acceptable than those in other packaging materials due to its considerable maintenance of the flour’s quality during and after storage.