 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 FOODS
Because the energy content of the main components of supplementary foods (cereals, pulses, defatted oilseed flours) is relatively low, the energy density of the product will also be low, resulting in bulky voluminous food. Such food is unsuitable for older infants and young children, whose stomach capacity is limited. With no extra fat (or sugar) added, the vegetable-based supplementary food has only 350-400 kcal per 100 g dry weight. The energy density may be increased by adding fat (or sugar) to reduce bulkiness and by special processing of the main ingredients . This processing may include toasting (roasting) of pulses and oilseeds, which improves flavour, taste, and digestibility (through dextrinization of starch) and reduces bulkiness.
Processing may also include sprouting and malting of cereals and pulses. This induces germination and predigestion of the starchy components, resulting in reduced bulk and increased nutrient density. Extrusion cooking and enzymatic predigestion are examples of more advanced processing technology to achieve basically the same results. For nutritional reasons, supplementary foods prepared from raw materials that have been specially processed as above do not require boiling during reconstitution with water. For hygienic reasons, however, boiling is usually required.
If processing alterations to reduce bulkiness are not feasible and packaging and storage conditions preclude pre-addition of fat, instructions should be given to add fats (and/or sugar) when preparing the supplementary food for consumption. This is particularly important if the supplement is to be used as the only food. If the protein content in the dry matter is 20 g per 100 9, about 20 g fat should be added (or an appropriate mixture of fat and sugar); about 10 g fat should be added if the protein content is 15 g per 100 g. This retains the protein calorie percentage at about 12-15, which is the range in mixed diets.
Although it would be desirable to incorporate adequate quantities of fat at the time of processin