What are processes of manufacturing Milo?

Answer 1

Milo is manufactured by evaporating the water content from a thick syrup at reduced pressure. The thick opaque syrup is obtained from malted wheat or barley and contains many mono-, di- and polysaccharides. Condensed milk and cocoa solids are added to give it a milk and chocolate content and it is often fortified with vitamins and minerals such as cyanocobalamin. Before the evaporation process it looks somewhat like very thick, light coloured coffee. This syrup is admitted to a large box constructed from thick steel plates and about 10 cubic meteres in volume. A number of conveyor belts are arranged inside the box and the syrup is drizzled onto the uppermost. The pressure inside the box is maintained just below the vapor pressure of water at a temperature of about 30 degrees celsius. Under these conditions of reduced pressure and slightly elevated temperature the syrup starts to boil. Eventually it reaches the end of the first conveyor whereupon it drizzles down to another, lower in the box. By the time it reaches the lower most conveyors it has become a soft vesicular solid somewhat like pumice stone or violet crumble. The evaporation at reduced pressure allows the water content to be removed at lower temperature according to the Clausius-Clapeyron relation and prevents the malt sugars and milk proteins from being changed by the heat, effectively cooking them and changing the taste and texture of the product. The whole process takes around an hour but operates in a continuous mode. At the bottom of the box the varying sized chunks of soft solid, from fist size to fine powder, fall from the last conveyor into an airlock where they are brought back to atmospheric pressure. The solid is introduced into a hammer mill where it is broken up into the final granular form. The rather hydroscopic granular powder is promptly packaged into cans by filling them from the "bottom", because the "top" end has been previously fabricated with an aluminium foil seal beneath the lid. The cans then have the tinplate bottoms affixed by a roll seam and the paper label is applied to complete the product. The prompt packaging ensures the product remains fresh and dry. Some other chocolate drink bases, such as Ovaltine, are made by a similar series of processes. Milo contains some theobromine, a xanthine alkaloid similar to caffeine which is present in the cocoa used in the product; thus, like chocolate, it can become mildly addictive if consumed in quantities of more than 15 heaped teaspoons per day. If a tin of Milo is not closed properly it will absorb water from the air and become damp and develop a tendency to form clumps. In very humid environments it can revert to the original opaque brown syrup; however, when made up as a beverage from this state its taste will have altered to the point that it is generally not consumable. Should the product become damp for any extended period of time it should be discarded because of possible bacterial action on the milk and sugar content. Use of very hot water when making a Milo drink can also alter the taste somewhat as will re-heating a made-up drink which has gone cold.