Oil quality from hydraulic pressed soybeans

Summary

HYDRAULIC pressed soybean oil quality is affected a great deal by the moisture of the beans at the time of milling. At moistures above 12 to 13% the oil quality deteriorates sharply. A great improvement in the oil from wet or even moisture damaged soybeans can be made by drying the beans in below 12% before milling. Even badly deteriorated (sample grade) beans have been vastly improved.

Blending of wet and dry soybeans to an average moisture below 12% does not seem to yield as good quality oil as drying wet beans to a corresponding moisture.

Normal variations in other soybean characteristics determining bean grade have lesser effects on soybean oil quality. Some data on the effect of bean damage, splits, off-color varieties, and foreign material are included in this paper.

Hydraulic oil mills operating on soybeans will be able to make large improvements in oil quality by drying whole wet beans at the mill and by removing foreign material from the beans.