Biorefinery process for protein extraction from oriental mustard (Brassica juncea (L.) Czern.) using ethanol stillage

Brassica spp. oilseeds are grown throughout the world as sources of vegetable oil and protein-rich animal feed (Henriksen et al. 2009). According to statistical data from the Canada Grains Council (2011), the average annual production of Canadian canola over the period 2001-2010 was 9.2 million tonnes, and the Canadian oilseed crushing industry produced an average of 2.1 million tonnes of canola meal annually between 2001-2010. Commercial oilseed extraction may include solvent extraction, mechanical expeller-press extraction, or combinations of mechanical and solvent extraction to produce oil and meal. Canola meal is the portion remaining after extraction of oil from canola seed and it is widely used as a protein source in poultry, swine, beef, and dairy cattle feeds because of its excellent amino acid profile (Hickling 2011).Thin stillage (TS) is a dilute stream of organic and inorganic compounds produced as a coproduct of the ethanol industry. Usually, TS is processed by drying than added to distillers dried grains (DDG) to produce DDG with solubles (DDGS). The latter is used in animal feeds. In the manufacture of DDGS, TS is first concentrated into syrup before mixing with wet distillers grains. TS drying consumes about 40-45% of the thermal energy and 30-40% of the electrical energy utilized in a dry-grind facility (Wilkins et al. 2006). The energy required to evaporate the large amount of water entrained in TS is a major cost in the ethanol industry and contributes to the poor lifecycle assessment of ethanol production (Bremer et al. 2010). To overcome the losses in energy for this process several strategies have been proposed including feeding wet distiller's grains with solubles. This has the advantage of decreasing the cost of drying but necessitates transporting water with the feed product to the animals. In addition the wet products may not be suited for storage.Production of protein isolates is equally inefficient. For examples, Newkirk et al. (2006) disc