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close this book Food Chain - Number 22 - January 1998
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View the document Greetings
View the document Research notes - utilisation of tomato processing by-products
View the document Shea nut processing - possibilities and problems in the choice of technology for women
View the document Booklines
View the document Weaning foods
View the document Latin America pages
View the document Coconut processing in the Mekong delta
View the document Asia pages

Weaning foods

It is possible to make improved weaning foods from local raw materials based on well understood, traditional, simple, low cost technologies.

The weaning period, from around 4-6 months until 2 years of age, is a critical period of a child's life when it is most at risk from malnutrition and disease. Adequate nutrition at this stage of life is reflected by physical and mental development and achievement in later life.

Weaning is the stage when an infant moves from a diet consisting exclusively of breast milk to one which resembles that of adults in the community. The transition generally takes place over 18 months, with breast milk making an ever decreasing contribution to the diet. The introduction of other foods into the diet, is often linked to an increased ingestion of food poisoning organisms that result in sickness and diarrhorea. In some societies additional foods are introduced into the diet earlier than 4 months of age but there is no nutritional requirement for this as breast milk alone is adequate until this age; furthermore, the practice its harmful and simply exposes the infant to contaminated water and food.

For a number of reasons infants are often weaned directly onto the adult diet with little or no consideration for their specific dietary needs. It may be, for example, that the local staple is the only available food and mothers have insufficient income to buy supplementary foods. Infant feeding is time consuming, both in the food preparation and feeding of the meal. The infant stomach is small and ideally the child should he fed at frequent intervals throughout the day; however, demands on womens time are usually so high that there is not enough time for infant feeding. Where income, availability of raw material and time are not constraints, poor feeding practices can be attributed to ignorance, illiteracy and the adherence to local customs and taboos.

Traditional weaning foods around the world are generally based on a porridge or gruel made from the local staple. For example, maize, banana, rice, plantain, cassava and wheat. In rural areas where refrigeration is not an option, gruels made in the morning are left to stand all day with an increased danger of the growth of food poisoning micro-organisms (pathogens) and contamination by dust and flies. In addition, in order to make gruels more palatable, mothers often water them down; sometimes after preparation with contaminated water. Although easier to eat, diluted gruels are low in energy and so have to be consumed in large amounts to meet the nutritional needs of the infant.

Experiences from many countries however, have demonstrated that it is possible to make improved weaning foods from local raw materials based on well understood, traditional, simple, low cost technologies. Small enterprises and individual households can make acceptable, nutritious products. Before examining some of these examples we need to consider the basic requirements of a weaning food.

Nutritional requirements

• high energy content

• low viscosity, i.e. of an acceptable thickness/consistency

• balanced protein (containing all essential amino acids)

• vitamins (particularly A, D and B group)

• minerals (iron, folic acid, calcium) e no anti-nutritional components e pleasant taste/palatable

Physical requirements

• easy and quick to prepare

• easy to consume

• adequate shelf life

• made from local ingredients

• affordable e safe micro-biological quality

The nutritional importance of a balanced protein composition is well understood in most cultures but deserves further explanation. There are many different types of protein and all are made up of long chains of amino-acids. Some of these amino-acids, in particular two called lysine and methionine, are often called limiting amino-acids, that is to say they are found in limited amounts in some foods. Cereal proteins are low in lysine while legume proteins are low in methionine. The consumption of cereal protein plus legume protein acts in a complimentary manner. This is the reason that many traditional diets are based on a legume/cereal mix (for example rice plus lentils, maize plus beans).

There are traditional processing methods available from different parts of the world, which are intended to improve the nutritional value of traditional weaning foods. These methods can he divided into four different categories;

• heating (toasting, roasting, puffing)

• adding sprouted or germinated grains

• fermentation

• fortification

HEATING

The action of heat on starchy foods causes the starch to pre-gelatinise which makes it easier to digest. Pre-gelatinised starch also takes less time to prepare. For example, porridge made from toasted maize will cook in 10 minutes compared to one and a half hours for untoasted maize.

Heating can also destroy anti-nutritional factors (these block the efficient absorption of proteins and nutrients into the gut) such as trypsin inhibitors and some tannins.

An example of a food made by simple toasting is Pushti, a traditional weaning food made in India from popped or puffed wheat. The cooking method is simple and one that is commonly seen in Asia for making puffed rice and for toasting peanuts. Cleaned, dehulled wheat is moistened with a little water and then added to a pan containing hot sand at

250-260°C (1kg of grain to 10kg sand). The grain and sand are stirred continuously for about 1 minute until all the grain has 'puffed'. The mix is then quickly sieved so that the grain does not burn. The puffed wheat grains are then ground to a flour. The wheat flour (700g) is mixed with soya flour (100kg) which has also been roasted over a fire for about 6 minutes, a process which removes the trypsin inhibitors present in soya. Sugar (200g) is also ground to a fine powder and added to the flours. In laboratory tests producing Pushti, a vitamin mix (la) was also added to the final mixture. At the village level where prepared vitamin mixes are not available, ground, dried leaves could he added as a source of vitamin A and iron.

ADDING SPROUTED OR GERMINATED GRAINS

Sprouted grains, such as barley, millet or sorghum, are rich in an enzyme called amylase which breaks down starch into sugars, thus making it easier to digest. Sprouted grains are traditionally used in the malting process to produce beer and this association is sometimes thought to make their use unsuitable for weaning food preparation. However, there is no alcohol produced during sprouting, only the conversion of starch to sugars. In addition to the breakdown of starch to sugars a major additional benefit is a reduction in the viscosity of the food, producing a sweeter, more palatable food, and thinner gruel.

The process is very simple and can quite easily be carried out at the household level. Cereal grains are allowed to sprout and are then ground into a powder or flour. A small pinch of the ground flour is added to a pot of starchy porridge. After a short time the viscosity of the porridge decreases to become liquid.

FERMENTATION

Fermentation has similar effects to germination of grains. The principle is the same, that is, breaking down the starch into sugars so that it becomes viscous and is easier to digest. Fermentation also improves the keeping qualities and increases the safety of foods by causing an increase in acidity which retards the growth of pathogenic micro-organisms that can cause sickness. In many parts of Africa milk sugar (lactose) intolerance is a serious problem. For this reason milk is commonly allowed to ferment, with a breakdown of the lactose, to a yoghurt a safer, longer life food.

Extreme care should be taken over the hygiene, quality control and safe handling of both the raw materials and finished products.

FORTIFICATION

A number of foods, including weaning foods, are fortified with other ingredients, notably vitamins and minerals, to increase their nutritional value. Common examples are the fortification of salt with iodine in order to control the outbreak of iodine deficiency diseases.

Weaning foods can easily be fortified by the addition of a little oil to a traditional starchy porridge. This increases the energy value, (10g of oil contains as many calories as 25g of starch) and also improves the flavour and palatability of a bland food. If the oil used is red palm oil, there are double benefits because this oil is high in beta-carotene which breaks down to vitamin A in the body (important for correct eyesight development).

Green leaves are a rich source of beta-carotene and also contain some iron. In Sri Lanka, a nutritious weaning food called Kola Kanda is made by adding leaf juice to cooked rice and coconut, the staple food of Sri Lankans. The juice is obtained by grinding leaves in a pestle and mortar. A more concentrated form of this supplement is obtained by boiling and curdling the extracted juice to form a protein and beta-carotene rich curd. An organization Find Your Feet has supported projects in several countries where leaf concentrate was used to fortify local foods and to improve the nutritional status of children. It is not, however, essential to extract the juice from leaves or to form a curd to enrich the starchy staple. Green leaves themselves are a nutritious supplement and mothers should be encouraged to include them in a weaning diet. As mentioned previously, dried, ground leaves can be used to fortify dried mixtures of cereals, pulses and oilseeds.

The examples described show that the production of nutritious weaning foods is a process which can be carried out at the small scale and at village level, by groups of women or individuals. It is based on locally available foods and traditional production processes and does not require sophisticated equipment. However, extreme care should be taken over the hygiene, quality control and safe handling of both the raw materials and finished products. During the preparation of weaning foods, hygiene is of utmost importance as contaminated weaning foods account for a substantial proportion of diarrhoeal disease and mortality among infants and children. The importance of food hygiene and safety in the preparation of foods and the prevention of diarrhoea, is often overlooked. Only simple measures are required as most contamination is due to factors such as polluted water, flies, pests, unclean pots and utensils, dirty hands and an unclean environment caused by inadequate sanitation.

There are several other considerations which must be taken into, account in order to establish a successful small business producing weaning foods. Although it makes common sense economically to use locally available foods in the preparation of weaning foods, there may he reluctance to buy the weaning foods for a number of reasons; the mother or carer is unaware of the dietary requirements of the infant; the supplementary food is too expensive and raw ingredients are not readily available; preparation of the foods can be time consuming and home-prepared foods may have a low status against the readily available commercial brands of weaning food. One of the most essential requirements is to increase the awareness of the mothers or carers to the importance of weaning foods in the infants diet. This role is carried out by nutritions extension workers and health workers. These people are also essential for helping to market the product against larger manufacturers who have an established reputation for quality and presentation.

Despite the many problems constraints, it is possible to make a readymade weaning food at the small scale.

In Ghana, Gratimix, a high protein weaning food made from groundnuts, maize and beans has been developed for small-scale production. The only equipment required is a corn mill, mixing bowls, a heat sealing machine, labels and polythene sachets. The three main ingredients are all cleaned separately, taking special care to avoid any groundnuts which may be contaminated by aflatoxin. After cleaning, they are roasted in an open pan to decrease the moisture content, (thereby prolonging shelf life), improve the digestibility of the nutrients and to de-activate enzymes and anti-nutritional factors. The roasted ingredients are cooled and the groundouts are dehulled after which they are mixed in the following proportions; maize 70%, cowpea 15% and groundnut 15%, and milled using a locally made corn mill to produce a fine flour. The flour is packed into double thickness polythene sachets and heat sealed. The product has a shelf life of three months.

In Hyderahad, India, womens groups in rural areas produce an instant weaning food called the Hyderabad mix. This mixture contains at least one cereal and one legume to provide a balance of amino acids. It also contains groundouts and local sugar for additional energy. The actual ingredients vary between seasons according to availability and price, but there is always one cereal, one legume and one oilseed. The ingredients are cleaned, dry roasted over a fire and then ground by hand on a stone. The flours are mixed together and packaged into plastic bags which are sealed over a candle. The weaning mixture can either be eaten as plain powder (by both adults and children), made into a porridge using milk or water, cooked as chappatis or made into sweet balls with jaggery (raw sugar). This weaning mixture is successful because it uses locally available ingredients, is flexible enough to change with variable availability of raw materials and uses a good balance of cereal, legume and oilseed.

High energy, high protein biscuits have the potential to make an ideal weaning food. Children love to eat biscuits, they are very easy to eat and do not require the assistance of the mother or carer and preparation time and costs are removed. The main constraint to their use may be increased cost above ordinary mass produced biscuits which can be found in most shops. Biscuits can be made from any types of locally available cereals, pulses and oilseeds. It is possible for production to be on the small-scale, using a clay bread oven or an oil drum oven. The following recipe makes a nutritious, high energy, high protein biscuit.

1. Choose a legume such as beans, an oil seed such as groundnut or sesame and a cereal such as maize or millet. Get some wheat flour.

2. Clean all the ingredients and throw away any groundnuts which are bad.

3. Roast the groundouts or sesame, taking care not to burn them. Pound and grind them into a fine flour or paste. Soak the beans and remove the skins. Dry them and grind into a fine flour.

4. Roast and grind the cereal.

5. Mix one part each of the groundout or sesame paste, the bean flour, the cereal flour and the wheat flour. Add a half part of sugar and 1 teaspoon of baking powder for every 10 big spoonfuls of mixture.

6. Add a half part of oil to the mixture to increase the energy value. Rub it in thoroughly until you have a dryish mixture.

7. Add clean water, one spoon at a time, until the mixture is pliable but not sticky. Mix well for 5 minutes.

8. Roll out the dough and cut into biscuits. Place them on a greased tray and bake in a hot oven for about 15 minutes.

9. When cooled, pack them into airtight containers.

This article was produced from contributions from the following; F W. Korthals Altes and P Dijkhuizen (AT Source, 19(2)); Motarjemi, F Kaferstein, G Moy and F Quevedo (Bull World Health Org. 71(1)); G Gordon (AT Journal, 14(2)); A Maddison and G Davys (AT Journal 14(2)); D Morley (Professor of Tropical Child Health, London University); ND Vietmeyer (Vetiver Network); S. Anokye-Mensah (Ghana Regional Appropriate Technology Industrial Service (GRATIS); K Krishna Kumari (Assistant Professor, Foods and Nutrition, PR and Research Centre, Rajendranagar, Hyderabad, India).

The actual ingredients vary between seasons according to availability and price, but there is always one cereal, one legume and one oilseed. High energy, high protein biscuits have the potential to make ideal weaning foods.