e 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 certain areas. Heating does not inactivate the toxic principles vicin and covicin in fava beans.
Oilseed flours (50 per cent protein), protein concentrates, and protein isolates (95 per cent protein) that are suitable for infants and young children include soya bean, groundnut, sesame, cottonseed, and sunflower seed. Appropriate conditions for the production of edible flours from soya beans, groundouts, cottonseed, and sesame are proposed in PAG guidelines nos. 5, 2, 4, and 1 4 respectively.
Dried, ground, edible fish species and edible fish-protein concentrates (with protein content of 70-80 per cent and a high lysine content) when produced under appropriate conditions (see PAG guideline no. 9) may be suitable to include as a protein source. Fish products, however, may introduce odours and flavours that are unacceptable in some cultures.
Refined or crude natural sugars are acceptable in moderation as raw ingredients to be added to increase the energy density and to improve palatability.
Fats also may be added (no more than 10 g per 100 g of product) to increase energy density and palatability. Vegetable oils and fats containing polyunsaturated fatty acids are preferred, but where advanced packaging technology is unavailable, these may reduce the shelf life because of oxidative changes (rancidity). Therefore, in many situations it is more advisable to add fat to the supplementary food at the time of feeding.
In selecting raw materials, attention should be paid to the colour, flavour, odour, texture, and consistency of the final product, realizing that these qualities must be acceptable to the mother before she will feed the product to her child. Traditional flavours added to supplementary foods may enhance acceptability. In addition, the raw ingredients in the formulated supplementary food should meet national and/or international standards with regard to wholesomeness and purity, content of toxic substances, and the inclusion of food additives .
NUTRITIONAL CONSIDERATIONS IN THE FORMULATION OF SUPPLEMENTARY FOO