GB654002A - Improvements in or relating to the removal of solvents from solvent-wetted vegetableresidues - Google Patents

Abstract

A protein-containing vegetable residue wetted with an oil-miscible solvent, e.g. hexane, is made into a slurry with an aqueous liquid and the solvent is evaporated at a temperature below that at which degradation of the protein occurs,e.g. the evaporation is carried out under a partial vacuum at a temperature less than 60 DEG C. The pH of the slurry may be reduced after removal of the solvent in order to precipitate at least a portion of the protein dissolved in the aqueous liquid; the undissolved material may be separated from the slurry before such precipitation is effected. The protein and oil-containing materials are exemplified by linseed, cottonseed, castor beans, soya beans, peanuts, hempseed, sunflower seed, oiticica nut, tungnut, coconut, carnauba leaves.ALSO:Foods from protein-containing vegetable residues wetted with oil-miscible solvents are obtained by making the residue into a slurry with an aqueous liquid and evaporating the solvent at a temperature below that at which degradation of the protein occurs, e.g. the evaporation is carried out under partial vacuum at a temperature less than 60 DEG C. The pH of the slurry may be reduced after removal of the solvent in order to precipitate at least a portion of the protein dissolved in the aqueous liquid; the undissolved material may be separated from the slurry before such precipitation is effected. The protein and oil-containing materials are exemplified by linseed, cottonseed, castor beans soya beans, peanuts, hempseed, sunflower seed, oiticica nut, tungnut, coconut, carnauba leaves. An example describes the making of a product of 96.25 per cent protein content by removing hexane from a slurry, of pH 11, obtained by mixing water and caustic soda with the residue, of 50 per cent hexane content, remaining after the extraction of the oil from ground flaxseed by hexane, centrifuging the liquid from the solids, adding to the liquid sufficient 5 per cent sulphuric acid to give pH 8.5, centrifuging to separate the precipitate so formed, and drying and pulverizing the precipitate.ALSO:Stock feeds from protein-containing vegetable residues wetted with oil-miscible solvents are obtained by making the residue p into a slurry with an aqueous liquid and evaporating the solvent at a temperature below that at which degradation of the protein occurs, e.g. the evaporation is carried out under a partial vacuum at a temperature less than 60 DEG c. The pH of the slurry may be reduced after removal of the solvent in order to precipitate at least a portion of the protein dissolved in the aqueous liquid; the undissolved material may be separated from the slurry before such precipitation is effected. The protein and oil-containing materials are exemplified by linseed, cotton seed, castor beans, soya beans, peanuts, hempseed, sunflower seed, oiticica nut, tungnut, coconut, carnauba leaves. An example describes the making of a product of 30 per cent protein content by removing hexane from a slurry, of pH 11, obtained by mixing water and caustic soda with the residue, of 50 per cent hexane content, remaining after the extraction of oil from ground flaxseed by hexane, adding sufficient 5 per cent sulphuric acid to give pH 3.5, separating the solids, washing the solids with water acidified to pH 3.5, drying and pulverizing.