Adding value to the lowest grade nuts by Supercritical CO2 industrial defatting process

Supercritical CO2 overcomes disadvantages of classic technologies

Supercritical CO2 reputation to obtain natural extracts containing lipid fractions is recognised in scientific and technical fields due to the well known fact of its high selectivity as well as its powerful performance. Small pieces of nuts yield high quality oils as well as richer vegetal proteins -with no solvent to be removed- almost ready to be used as ingredients or end products.

Many of the most desirable commercial applications are only possible in economic competition against well established commodities. Industry has applied for a long time different apparently cheaper techniques to extract oils and fats, from mechanical machinery to organic solvents and distillation.

These convenient and conventional processes use to involve thermal treatment as a production requirement (solvent extraction, solvent removal and distillation) or give rise to local heating due to internal and inevitable mechanisms (screw, press and cold-press).

Thermal and air exposures of labile components, such as oils and particularly PUFA, including such wanted oils as omega-3, and omega-6, prompt chain reactions leading to undesirable degradation and rancidity. In order to avoid these handicaps, big volumes of inert gases like nitrogen are used to displace air in production equipment, storage tanks and final bottles. In addition, raffinate is limited to be of further use because of its solvent content and/or thermal degradation.

Cosmetic oils and edible vegetal protein in just one cost-efficient step

Supercritical CO2 extraction of the lowest grade of nuts result in oils and vegetal proteins that can be used respectively, on one hand as cosmetic and food ingredients, and on the other hand as animal protein substitutive in fortified food industry.

Bad press for industrial use of dense CO2 is due to investment costs; however their impact on treatment costs is minimized when reflected over the whole quantity of treated raw material, as it is in this particular case. Moreover when increasing the lowest grade of nut to the best quality and hence value for money.