Optimization of spray drying process parameters for production of groundnut milk powder

Abstract

In India, groundnut is mainly used for oil extraction or consumed in roasted form prompting a need for diversification to further increase its value and utility. In the present study, spray drying of groundnut milk was carried out using three variables of spray dryer i.e., inlet air temperature (180–220 °C), atomization air pressure (2–3 bar), feed pump speed (24–36 rpm) using Box-Behnken design of Response Surface methodology. The moisture content of powder decreased with an increase in inlet air temperature and atomization air pressure. The bulk density increased with increase in atomization air pressure. Maximum dispersibility (98.48%) was observed at an atomization air pressure of 2.57 bar. The insolubility index of the powder increased and lightness value (L*) decreased with an increase in inlet air temperature. The optimized conditions for spray drying of groundnut milk were inlet air temperature: 186 °C, atomizing air pressure: 2.5 bar and feed pump speed: 27 rpm.