Patent GB-685044-A (GB)
Title: Purification of fatty oils
IPC: C11B3/10
Filed: 1949-03-12
Abstract: Higher fatty acid esters, such as ethyl oleate, are purified from peroxides, which at least in part cause rancidity, by contacting the ester in a substantially mobile liquid condition and in the absence of water and of organic solvents with ordinary magnesium oxide, i.e. not activated by heating, and thereafter separating the ester from the magnesium oxide.  The latter selectively adsorbs the peroxides. The temperature is such that the ester is liquid but below the temperature of decomposition; room temperature is preferred, where possible.  Powdered magnesium oxide may be added to the ester and after agitation for a sufficient time is removed by filtration. Alternatively, the ester may be passed through a column of the magnesium oxide in a coarse state of sub-division.  The treatment is preferably effected in the absence of light and oxygen; an inert atmosphere, such as nitrogen, may be used or preferably vacuum only. Other purifying treatments, such as bleaching, may be effected before or after or at the same time as the treatment with the magnesium oxide.  Thus, the magnesium oxide may be used mixed with a bleaching earth.  U.S.A. Specification 2,454,937 is referred to.ALSO:Fatty oils and other higher fatty acid esters are purified from peroxides, which at least in part cause rancidity, by contacting the oil &c. in a substantially mobile liquid condition and in the absence of water and of organic solvents with ordinary magnesium oxide, i.e. not activated by heating, and thereafter separating the oil from the magnesium oxide.  The latter selectively adsorbs the peroxides.  The specified materials treated comprise glyceride esters, such as olive oil and butter, and other higher fatty acid esters such as ethyl oleate.  The temperature is such that the oil is liquid but below the temperature of decomposition; room temperature is preferred where possible. Powdered magnesium oxide may be added to the fatty oil and after agitation for a sufficient time is removed by filtration. Alternatively, the fatty oil may be passed through a column of the magnesium oxide in a coarse state of sub-division.  The treatment is preferably effected in the absence of light and oxygen; an inert atmosphere, such as nitrogen, may be used or, preferably, vacuum only.  Other purifying treatments, such as bleaching, may be effected before or after or at the same time as the treatment with the magnesium oxide.  Thus, the magnesium oxide may be used mixed with a bleaching earth.  U.S.A. Specification 2,454,937 is referred to.ALSO:Butter is purified from peroxides, which at least in part cause rancidity, by contacting the butter in a substantially mobile liquid condition and in the absence of water and of organic solvents with ordinary magnesium oxide, i.e. not activated by heating, and thereafter separating the butter from the magnesium oxide.  The latter selectively adsorbs the peroxides.  The temperature is such that the butter is liquid, but below the temperature of decomposition; room temperature is preferred where possible. Powdered magnesium oxide may be added to the butter and after agitation for a sufficient time removed by filtration. Alternatively, the butter may be passed through a column of the magnesium oxide in a coarse state of sub-division.  The treatment is preferably effected in the absence of light and oxygen; an inert atmosphere, such as nitrogen, may be used, or, preferably, vacuum only.  Other purifying treatments, such as bleaching, may be effected before or after or at the same time as the treatment with the magnesium oxide.  Thus, the magnesium oxide may be used mixed with a bleaching earth.  U.S.A. Specification 2,454,937 is referred to.