A solid bed adsorptive process for separating a seed oil into two substantially pure triglyceride fractions. The process involves contacting a seed oil, such as castor oil, preferably as a concentrate, with an adsorbent in a bed, the adsorbent having a particle size greater than about 40 microns, and thereafter contacting the adsorbent with a desorbent material, preferably under minimal flow conditions, to obtain a raffinate output stream containing predominantly a second triglyceride and an extract output stream containing predominantly a first triglyceride. Purified fatty acid triglyceride esters obtainable from castor, vernonia, and lesquerella plant oils provide renewable, non-petroleum-based sources of chemical feedstocks.