Supercritical carbon dioxide extraction of wheat distiller's dried grain with solubles.

A wide variety of carbohydrates and starch-containing materials have been used for production of ethanol by the fermentation process. The alcohol from grain such as corn, wheat, barley, and sweet sorgum produced dried distillate grain with solubles (DDGS) and carbon dioxide as by-products. An attempt has been made to extract fatty oil from wheat DDGS using supercritical carbon dioxide (SC-CO₂). Wheat DDGS contain 65-70% of omega-3-fatty acid and omega-6-fatty acid. The fatty oil was also extracted from wheat DDGS by the Soxhlet method using hexane. The chemical compositions of fatty oils were determined by carbon, hydrogen, nitrogen and sulphur analyser, gas chromatography-flame ionization detector and gas chromatography/mass spectrometry. SC-CO₂ is a suitable process for extraction of fatty oils with an improved percentage of essential fatty acids such as omega-3-fatty acid and omega-6-fatty acid.