Mechanical oil expression from extruded soybean samples

Soybean is generally recognized as a source of edible and industrial oil, a nd the deoiled meal is seen as a source of protein in animal feed. In recen t years, however, more interest has been directed toward using soy meal as a protein source for human consumption. Extrusion-expelling of soybean prov ides an opportunity in this direction. The main focus of this study was to maximize the oil recovery from extruded soybean processed using three diffe rent kinds of extruders and processing conditions. These extruded samples w ere later pressed uniaxially in a specifically designed test-cell and the o il recovery was recorded over rime. The effects of process variables, inclu ding applied pressure, pressing temperature and sample height, were investi gated. Results indicated that over 90% of the available oil could be recove red from pressing of extruded soy samples. The information generated is lik ely to be useful in interpreting the effect of process variables and extrud ing equipment for pretreatment of soybean for subsequent mechanical oil exp ression.