Effect of Piliostigma thonningii fruit pulp addition on nutritional, functional, and sensorial properties of maize flour blends

Abstract

Piliostigma thonningii (monkey bread fruit) is an underutilised indigenous fruit of southern Africa. P. thonningii pulp flour of concentrations 15%, 25%, 35%, 50%, 65%, and 80% (w/w) was blended with maize flour (MF). Nutritional, functional, and sensory properties of maize flour and flour blends (MBF+MF) were determined using standard methods. Results showed a significant increase in least gelation concentration (6–10%), emulsion activity (44.8–55.3%), emulsion stability (40.2–52.1%), swelling capacity (2.12–5.23 g/ml), swelling index (0.5–1.98), oil absorption capacity (1.12–3.1 ml/g), water absorption capacity (191.2–270%) and decrease in bulk density (0.73–0.4 g/ml) and least gelatinization temperature (63.6–52.1°C) with increase in the addition of MBF at different percentage weights. Protein content increased from 10.2% to 14.8%, crude fibre increased from 3.5% to 4.8%, ash increased from 2.1% to 3.0%, and carbohydrates decreased from 74.0% to 66.3%. Iron and calcium content increased from 2.11 to 3.11 mg/100 g and 8.12 to 9.12 mg/100 g, respectively. The food gel prepared with 25% MBF/75% MF was most preferred with respect to colour, texture, flavour and overall acceptability. The flour has the potential to supply over 30% and 80% of the recommended dietary allowance for iron and carbohydrates in children's diets.

Keywords

• piliostigma thonningii
• flour blend
• swelling capacity
• oil absorption capacity
• least gelatinisation temperature
• least gelation concentration
• sensory quality