A study of yield characteristics during mechanical oil extraction of preheated and ground soybeans

Abstract

Soybeans were extracted for oil by compressing a ground sample at various operating pressures, pressing durations and product bulk temperatures. The oil yield from the various operations was measured and e xpressed as a percentage of the original mass of crushed seeds. It was found t hat the oil yields increased linearly with increase in pressure as the compression p ressure was increased from 40 to 80 kgf/m and that oil yield also increased linearly with i ncrease in t he d uration of pressing wi thin t he range 2 It was also f ound beneficial to dry the seeds to a moisture content slightly below t he am bient moisture content of 9.3% (d.b.) although reducing moisture to a value lower that 5% (d.b.) r esulted in a reduction in oi l yield. A si ngle e mpirical model fo r estimating the oil yield f or v aried condi tions of pressure, duration of pressing and the bulk temperature of oil bearing material was developed which could estimated the yield wi th g ood accu racy within t he experimental range.