Corn flakes processing and manufacturing
Ready-to-eat (RTE) breakfast cereals originated in the United States in the late 19th century. Cornflakes are the product obtained from dehulled, degermed and cooked corn (Zea mays L.) by flaking partially drying and toasting. Various kinds of vitamins and mineral substances can be added. Maize, the main raw material, is itself a corn grain. Corn flakes have very good taste.
Corn flakes can be manufactured either of the two white or yellow corns. Maize is cleaned, polished and milled to remove the germ and bran. The milling process removes the corn kernels from the cobs and turns them into flaking sized 'grits'. The first step in converting raw flaking grits into corn flakes is to mix them with a flavor solution containing sugar, salt, malt syrup and other ingredients in water.
The broken pieces, which are comparatively big in size are cooked under pressure in a rotary steam cooker at temperatures exceeding 100°C. The grits and flavor solution may be loaded simultaneously, or the grits may be added first and pre-steamed, followed by flavor addition and mixing.
Maize is cooked for about 2 hours along with the flavoring agents, if necessary. During cooking additional water is incorporated in the form of steam which condenses and the water content in the batch rises to 30-35%.
Hence to reduce the moisture content to about 15% to 20%, pre heated air is blown. The dried material is kept in the tempering tank to enable the residual moisture to become distributed equally.
The tempered material is now passed through the heavy-duty flaking machine fitted with magnetic separator and water-cooling system. For flaking of corn grits, roll surface temperature is 45°C. Temperatures over 50°Ccause excessive roll wear and product sticking to the roll surface.
The maize flakes are then roasted in suitable ovens. The air in the ovens is heated by 600°C 0 gas flames and the flakes are tossed around in a rotating drum. The drum is angled so that the flakes whirl around and pass through it quite quickly, and stops them spending too long in the fierce heat.
The roasted flakes are then graded and packed in polythene containers or other suitable packaging materials.