(introduction...)

Roller mills - for developing countries too
by Hans-Wilhelm van Haugwitz

Cereals, particularly wheat and maize, are among the basic foodstuffs in developing countries. The ripe grain is rough-ground or milled to a fine flour and then further processed into gruel or bread. Cereals certainly owe their extraordinarily widespread popularity as a foodstuff for man and beast to the fact that they are balanced and valuable nutrients. Their nutritive content corresponds very closely to human requirements.

In slightly simplified terms, a grain of cereal consists of the husk, the farinaceous kernel and the germ. The germ can be described as a concentration of nutritives and is rich in all kinds of active ingredients. The kernel consists mainly of carbohydrates while the husk mainly contains ash and ballast substances.

It requires no further explanation to see that, ideally, the whole of the grain should be used as food, without anything being removed or modified. But this is only possible if the bread or gruel produced is destined to be eaten directly after the corn has been ground. This was the custom until modern milling methods were introduced. This total utilization is now once more being propagated by nutrition experts.

But there are problems if it is not possible for milling and food preparation to follow one another directly. Rough-ground maize, for example, becomes unpalatable for human beings after about four days' storage. It becomes bitter, acquiring a rancid taste and stale smell.

The reason for this is that the fats contained in the germ and the husk oxide after crushing. If germ and husk are sieved out during the milling process, the flour from the farinaceous kernel can be stored for extremely long periods. This flour, however, consists almost exclusively of carbohydrates. Modern roller-milling techniques are used to produce this "long-life" flour.

The finely-ground flour produced in rolling mills has found wide acceptance particularly in the large towns and population areas of developing countries. There are various reasons for the popularity of this low-nutritive yet storable flour:
- All consumers have regular incomes.
- Families in the high-income range give up the extremely labour-intensive job of grinding the corn and buy other foodstuffs to replace the missing nutrients.
- In many families both husband and wife are at work all day. Families with lower incomes often live a long way from their workplaces, so that they are away from home for up to sixteen hours. They grasp any opportunity of reducing the amount of household work required, even though the replacement of a foodstuff of superior nutritive value by low-nutrient flour is particularly problematic for the poorer families.
- Many husbands live alone in towns away from their families. They, too, often spend many hours a day away from home and do not take their meals regularly, which means that they also prefer to use storable flour.
- The cereal mills for home use offered for sale in developing countries at the present time are much too expensive for most families. The machines offered by manufacturers in industrialized countries depend on the availability of electricity and high income purchasers. Such goods will only be of interest in areas where special attention is paid to a balanced and healthy diet.

Given these circumstances, it would seem rather hasty to condemn roller milling techniques simply because they produce a foodstuff which, in view of its nutrient composition, cannot be regarded as of high nutritional value.