GB701633A - Improvements in or relating to a process of deodorizing glyceride oils and products resulting therefrom - Google Patents

Abstract

Edible glyceride oils are deodorized by subjecting a shallow pool of the oil to a number of steam treatments under vacuum at progressively lower temperatures, the first treatment being effected at a temperature not less than 500 DEG F. and the final treatment at a temperature not higher than about 350 DEG F. The oil may first be alkali-refined or solvent-extracted. As shown, oil from a tank 10 is passed through a constant-level deaerating tank 11 to a heater 17, where it is heated under vacuum and agitated by steam from a perforated pipe. The oil is then progressively heated in annular heaters 19, 20, 21, preferably to 525-575 DEG F., and is then delivered through a pipe 27 to the deodorizing chamber 26, shown in detail in Fig. 2, where it forms a shallow pool, e.g. of 10-20 inches depth, below a perforated plate 31. Steam is introduced through small holes in the pipe 30 and vapours are drawn off through baffled openings <PICT:0701633/III/1> <PICT:0701633/III/2> 29. The oil then passes alternately through coolers 39, 42 and 44 and chambers 41, 43 and 46 (similar to the chamber 26) in which it is treated again with steam under vacuum, and finally the oil is cooled in a cooler 47 and passed to a storage tank 48. The vapours withdrawn from the chamber 26 pass first to a condenser 51, condensate from which is collected in a tank 52. Residual vapours from the condenser 51 are passed through vacuum-boosters 54, 55 to jet condensers 56, 57, uncondensed residue from which in discharged through vacuum-boosters 58, 59. The condensate and water are collected in a tank 68. The vapours withdrawn from the chambers 41, 43 and 46 pass to a vacuum-manifold 60 cooled by a jacket 621 and connected to a vacuum-booster 62 which discharges into the condenser 56. Condensate forming in the vacuum manifold 60 is collected in a tank 63. The condensates in the tanks 52, 63 and 68 may be withdrawn separately, or those in the tanks 52 and 63 may be pumped to the tank 68, from which a single condensate is then withdrawn. Tocopherols, sterols, vitamins and fatty acids are recoverable from the condensate(s). The process is described with reference to the treatment of soya-bean oil, which may be hydrogenated after the deodorizing treatment described above and then deodorized again under milder conditions. Other oils which may be treated are cotton-seed, corn, peanut, sunflower-seed and sesame-seed oils and fish oils. Specifications 701,631 and 701,632 are referred to.