Patent GB-480556-A (GB)
Title: Improvements in or relating to the manufacture of stable powdered products containing milk sugar
IPC: A23C1/04
Filed: 1937-04-06
Abstract: <PICT:0480556/III/1> A substantially non-hygroscopic powdered product for human or animal food is produced from lactose-containing solutions, such as whey, by spray-drying to form directly a powdered product in which sufficient water is retained so that the lactose in the final product is in the form of hydrate.  The liquid may be concentrated, prior to spray-drying, to a 40-60 per cent solids content by weight.  The spray-drying may be effected by spraying into a gas which is at an outflow temperature of 130-150 DEG  F. Whey may be pasteurized, then neutralized to prevent inversion of the lactose where the whey has been obtained by acid treatment of milk, and concentrated to 45-60 per cent solids content, the liquid particularly at the higher concentration being supersaturated in respect to lactose.  The spray-drying is then effected so as to give the desired moisture content in the product, in one case 12-14 per cent by weight over that required for conversion of the lactose present to mono-hydrate.  The product obtained usually still contains too much free moisture and is further dried, e.g. with drying gas at 140 DEG  F. to reduce the free moisture to about 4 per cent without removing water of crystallization.  Spray - drying is effected in chamber 10 supplied through one or more conduits 11 with hot gas which is withdrawn through conduits 12, the liquid being supplied to a centrifugal atomizer 13, which is surrounded by a baffle wall 14 which directs the hot gases entering into an annular stream around the atomizer.  An atomizing orifice supplied by a high-pressure pump may replace this atomizer.  Particulars of the operative conditions used are given, with gas inflow and outflow temperatures.  The powder is removed continuously or intermittently through a discharge conduit 15 by means of a gate 16 and passes to a finishing drier 18 and then through a blower 19 which delivers it to a separator 20 of the cyclone or bag type. The drier 18 may be a revolving drum through which drying gas is passed, or a chamber in which the material is suspended in drying gas.  U.S.A. Specification 1,928,135 is referred to.  The Specification as open to inspection under Sect. 91 refers also to the treatment of materials containing other sugar, e.g. malt syrup.  This subject-matter does not appear in the Specification as accepted.ALSO:A substantially non-hygroscopic powdered product for animal food is produced from lactose-containing solutions, such as whey, by spray-drying to form directly a powdered product in which sufficient water is retained that the lactose in the final product is in the form of hydrate.  The liquid may be concentrated, prior to spray-drying, to a 40-60 per cent solids content by weight. Whey may be pasteurized, and then neutralized to prevent inversion of the lactose where the whey has been obtained by the acid treatment of milk, and concentrated to 45-60 per cent solids content, the liquid, particularly at the higher concentration, being supersaturated in respect to lactose.  Spray-drying is then effected to give the desired moisture content in the product, in one case 12-14 per cent by weight over that required for conversion of the lactose present to monohydrate.  The product obtained is further dried, e.g. with drying gas at 140 DEG  F., to reduce the free moisture to about 3 per cent without removing water of crystallization.  Apparatus for effecting the spray-drying is described.