| FOOD CHAIN No. 8 - March 1993 |
Processing can have either positive or negative effects on the nutritional value of foods, depending on the process and the food in question. For example the nutritional value of kidney beans is improved through boiling because anti-nutritional factors are destroyed in the process, the separation of cereal bran removes physic acid which inhibits calcium absorption and the vitamin content of soya beans is increased when they are fermented to temper, or soysauce.
But food processing can. also have negative nutritional effects: boiling, frying and drying all cause loss of vitamins that are sensitive to heat or air. More severe heating, as in canning, results in greater loss of vitamins In addition processes that remove parts of the food, such as polishing rice, mean that the nutrients are lost because they are not eaten.
However, for people who have enough food or a balanced diet, these considerations are not very important. Any loss of nutrients in one part of the diet will be made up from foods in another part of the diet and the total food intake will keep people healthy But for those people whose diet is unbalanced or those that do not have enough food, any losses can have a substantial impact on their health. Chronic shortages and imbalances in food supply affect a much larger number of people worldwide, but the effects of these take longer to appear.
Infants and small children are especially vulnerable to an unbalanced diet because the loss of particular nutrients can affect their growth and development at a critical stage of their lives. Poor families are unable to afford nutritious foods such as milk or fish to wean their children and often resort to cheap staples such as cassava that are deficient in proteins, minerals and vitamins. For this reason supplementary feeding programmes have been implemented for many years to correct imbalances in the diets of children from poor families.
In this issue of Food Chain we describe some examples of successful supplementary feeding programmes including the use of leaf concentrate for poor families in Bolivia, the fermentation of ogi in Nigeria, a fortified Guatemalan cookie and the fortification of maize meal for Mozambican refugees in Malawi.
ROOT CAUSES OF HUNGER
The causes of poor nutrition, whether acute or chronic, are fundamentally social and economic. If a family has insufficient land to support its food needs; if inadequate or inefficient food distribution leads to food shortages and price increases in one region despite plentiful supplies in another; or if price control policies place the cost of foods beyond the reach of poor people; each will result in malnutrition.
Although supplementary feeding has a valuable place in preventing or relieving the suffering of young children and giving them a chance to grow and reach their full potential, it is not a long term solution to the problem of world hunger. It is for the politicians, not the nutritionists and food technologists to address the inequalities that result in hunger.