be recognized. These foods help to condition (educate or acculturate) infants and young children to a wider diet at weaning by providing experience with transitional liquid-to-solid variations in consistency, texture, and taste.
The nutrient composition of formulated supplements may have to be adapted to local circumstances since these foods are meant to provide such nutrients as are lacking in the basic staple food as defined by the Codex Alimentarius Commission [1, 2]. Local economic, cultural, and social acceptability factors also may influence the proposed composition of main ingredients. In addition, adjustments of a base formulation to reflect local conditions of use may require additions or deletions of certain vitamins and minerals to ensure that the daily total intake remains within safe limits.
Of greatest concern is assurance that the total diet provides the essential vitamins and minerals at a level that meets minimum nutritional needs, and that the intake of nutrients that are stored in the body, such as fat-soluble vitamins and minerals, does not consistently exceed maximum safe limits.
RAW MATERIAL USED IN SUPPLEMENTARY FOODS
In developing countries, for social and economic reasons, the raw materials used in supplementary foods should come from locally available ingredients wherever possible. The supplementary foods that are considered here are entirely or mainly based on raw material of vegetable origin. The basic ingredient is a cereal, to which are added pulses and/or oilseed flours. Animal products, such as fish or fish-protein concentrate and milk-powder products, could, or should, be added if feasible, acceptable, and economical. To increase the energy density, fat (and/or sugar) should be included among the ingredients or added to the food when it is eaten.
All milled cereals may be used to make supplementary foods. Certain cereals with a high fibre content such as millet, sorghum, and teff should be processed in such a way as to reduce the fibre content. The model composition proposed by the Codex committee suggests 5 g crude fibre per 100 g of product, but acknowledges that a higher fibre content may be acceptable after clinical testing . It should be recognized that, in addition to carbohydrates, cereals contain a substantial amount of protein (8-12 per cent).
The combined use of cereals and pulses takes advantage of the fact that cereals (except rice) are relatively deficient in lysine while pulses have a high lysine content. A mutual amino acid complementation is thereby achieved by the combination, and the protein quality is improved. Tentatively, the ratio of cereal to pulses should be in the range of 3:1 or 4:1 in order to obtain the best mutual lysine complementation . The quality may be improved further by adding small amounts of fish or milk products (or L-methionine). These additions, although desirable, may increase costs and may not be necessary if even small amounts of breast milk are given, or if the children are eating a reasonably mixed diet. The importance of these additions increases, however, if the supplementary foods are to be used for long periods as the only food.
The proportions in which the different raw materials are to be included should be governed by the desired final composition of the supplementary food as it relates to the total diet and by the intended use. Economic aspects should also be considered, particularly when it comes to the possible inclusion of animal food ingredients.
Although pulses provide a good source of protein (20-24 per cent), too high a proportion of pulses may be undesirable because of their content of anti-nutritional factors [1, 2], their need for long cooking times, and their tendency to produce flatulence. Examples of anti-nutritional factors are lectins (haemagglutines), trypsin, and chymotrypsin inhibitors. These factors can be destroyed by heating, pressure cooking, or prolonged cooking . Fava beans should not be used when a deficiency of glucose-6-phosphate dehydrogenase (G6PD) is known to be prevalent because of the danger of favism in