Modification of Complementary Foods in Zambia

By Victor Ochieng Owino

Victor is currently a PhD student at the Centre for International Child Health, University College London. A Food Science and Technology graduate, he has previously worked as a research assistant at the University of Nairobi and held a technical position at a Nairobi based food company.

The author wished to acknowledge the contribution of the Ellison Medical Foundation, Nutrition Third World and Score Africa to this work.

This article is an overview of an ongoing study in Lusaka, Zambia, which is working on modifying complementary (infant) foods with ?-amylase. Given the critical need to develop at a local level, palatable, affordable and nutritious complementary foods for HIV positive mothers which allow abrupt weaning following breast-feeding, the initiative described here is an important development. (Ed)

Poor quality complementary foods, characterised by high viscosity and low energy density, and inappropriate feeding practices have been highlighted recently by the World Health Organisation (WHO) as part of the major causes of malnutrition in children. This is especially true in the second semester of the first year of life in poor settings. Some of the approaches to improve the quality of complementary foods include fortification and the enhancement of energy density by the application of starch-breaking enzymes, such ?-amylase.

Chilenje clinic staff with the new complementary food

A two-phased study has been undertaken in Lusaka, Zambia since 2003, to assess whether modification of complementary foods with ?-amylase and multi-micronutrient fortification benefit infant growth and micronutrient status. The study also aimed to generate data on breast milk intake of nine month old infants, using a technique where a stable isotope dose is administered to the mother. This was a collaborative study that brought together the Centre for International Child Health (CICH), London, the Lusaka District Health Management Team, the National Institute for Scientific and Industrial Research (Lusaka) and Quality Feeds Limited (Lusaka).

Methods

The study was based at Chilenje clinic, Lusaka, a middle-income urban area where most households have running water and flush toilets. Ethical approval was obtained from the University of Zambia Ethics Committee and Great Ormond Street Hospital, UK.

The first phase of the study, carried out in 2003/2004, comprised an assessment of complementary feeding practices among mothers of children aged 6-23 months old in Chilenje, Lusaka, and the development and assessment of the acceptability of an ?-amylase-modified complementary blend made from locally produced cereals and legumes.

Complementary feeding practices were assessed by qualitative techniques using focus group discussions and formal interviews. Infants' nutrient intake was assessed by 24h-recall and 12h weighed food records. Focus groups discussions were held with mothers, fathers and health workers at Chilenje clinic. A total of 34 mothers were interviewed, of whom 20 were observed at home to determine how they prepared food and fed their children. Data from 24h and 12h weighed food records were used to compute the amounts of energy, iron and calcium obtained from family meals by children aged 6 -23 months old.

The acceptability of the developed porridge was assessed using sensory evaluation by 18 mothers at Chilenje clinic. Ablend was developed using maize, beans, groundnuts and bambaranuts and was treated with ?-amylase after roasting and hammer milling. Porridge viscosity was measured at different slurry concentrations (9-20%) in order to determine the amount of additional dry flour possible without a notable change in porridge consistency. The viscosity of habitual porridges was determined after simulating mother-reported and observed recipes.

Acceptability of new blend

The results showed that maize (Zea maiz) is the main cereal used in Lusaka. The available, and widely used, legumes are common beans (Phaseolus vulgaris), groundnuts (Arachis hypogea) and bambaranut (Vorandzea subterranean). Although commercially processed complementary foods are available in Lusaka, they are very expensive, with the lowest priced selling at US$4 per kg. Thus, lack of affordable complementary foods was found to be a major constraint on mothers' feeding practices. On the contrary, the developed blend would cost only US$2.5 per kg. Treatment of porridge with ?-amylase allowed for a 100% increment in porridge slurry concentration without a change in porridge viscosity. The study blend was widely accepted by mothers.

Micronutrient status and growth

It was observed that although children received the recommended amounts of energy from habitual foods, they received less than half of their daily requirements for iron and calcium. This highlighted the need to fortify complementary foods to meet the micronutrient needs of infants, and necessitated the second phase of work that is currently underway. This aims to assess the benefit of ?-amylase-treated, multi-micronutrient complementary blend on growth and micronutrient status of infants aged 6 - 9 months old. The complementary blend, developed in phase one of the study, was industrially processed by extrusion cooking in collaboration with Quality Feeds Limited. The food was fortified using a multiple micronutrient premix based on the latest WHO recommendations for infants 6 - 9 months old. The fortified blend was either treated with ?-amylase or not.

Mother-infant pairs, recruited at Chilenje clinic, were randomised when the child attained 6 months of age to either receive ?-amylase treated fortified blend, or non-?-amylase treated fortified blend. The control group comprises mother-infant pairs who were recruited when the infant was 9 months old and were measured once, alongside mothers and children from the intervention groups.

Each infant in the intervention is provided with 2 kg of porridge flour per month, while those in the control group receive at least 4 kg (2 months supply) of porridge after all the measurements are made. Monthly anthropometric measurements (weight, length/height, body circumferences and skinfolds) are performed on both the mother and the infant. Haemoglobin is measured in the infant at 6 months of age and at 9 months. Monthly intake of nonbreast milk foods is determined by 24h recall. A sample of both control and intervention mothers receive a dose of deuterium oxide when the infant turns 9 months, and urine samples are collected over a period of 14 days to determine infants' breast milk intake.

Observations

The main strength of the project is the fact the main ingredients (maize, groundnuts, bambaranut and beans) are locally produced in Zambia. Maize and pounded groundnuts are the most common ingredients used to prepare porridge for infants from as early as 2 months of age¹, while beans are commonly used to make stews. However, the cooking of maize-groundnut porridge normally takes 30 - 45 minutes. The advantage of the developed blend over habitually used porridges is that it is already pre-cooked and takes a maximum of 20 minutes to cook. Additionally, ?-amylase is widely used in the baking industry in Zambia and can be readily accessed from local dealers. Minerals and vitamins for fortification can easily be sourced regionally.

The main observation has been that the developed blend is widely accepted by mothers who report that their children like the porridge. Mothers have also expressed willingness to buy the porridge if it were to be available in the shops. This shows that future scale up of this work is feasible. The viability of this work also depends on the already established collaboration among government, research institutions and the private food industry.

For further information, contact Victor Ochieng Owino, Centre for International Child Health, Institute of Child Health, Guilford Street, London WC1 1EH, United Kingdom Email: vowino@hotmail.com

¹Current WHO guidelines recommend that complementary foods be introduced in addition to breastmilk from six months of age. For guidance and resources on complementary feed ing, see http://www.who.int/child-adolescent-health/NUTRITION/complementary.htm