Production of extrudate pasta from optimal sorghum–peanut flour blend and influence of composite flours on some quality characteristics and sorption isotherms

Utilisation of composite flour projects the possibility of improving nutritional quality, and consequently, the awareness of quality stability may increase large-scale commercialisation of different food products. Quality characteristics of sorghum–peanut flour blend and its extruded product (pasta) were investigated in this study. A model of moisture sorption isotherms for sorghum–peanut flour blends using concentrated H₂SO₄ was developed. The sorghum–peanut flour blends were substituted in the ratio of 100:0, 90:10, 80:20, 70:30, 60:40, 50:50. The experimental data obtained were compared with neuro-fuzzy and Guggenheim–Anderson–de Boer (GAB) models for food sorption isotherm. The results showed that all the quality characteristics of the flour investigated significantly (p < 0.05) influenced each other due to the level of substitution of peanut flour. The extruded sample with 90% sorghum and 10% peanut flour was the most preferred and accepted by the sensory panellists. The adsorption and desorption isotherm curves followed a sigmoidal shape and the equilibrium moisture content increased with an increase in water activity. The neuro-fuzzy model predicted optimally and was observed to be better in describing sorption isotherm of sorghum–peanut flour blends than the widely known and acceptable GAB model.