1.1 Background to the study
Breast milk is the ideal food for infants during the first six months of life. This is because breast milk contains still-undiscovered substances that cannot be reproduced artificially and its overall nutrient composition is superior to any alternative, including infant formula (Srilakshmi, 2008). In spite of its superiority, breast milk alone is not able to provide sufficient amount of all the nutrients and calories needed to allow infants thrive after the first six months of life. As the child grows, the caloric and nutrient needs cannot be met by the diminishing output of mother’s milk or infant formula. If the baby is to maintain the expected rate of growth and remain healthy and well nourished, complementary food should be introduced at about the sixth month of life (WHO, 2001). The semi-solid food given to infants in addition to breast milk at about six months of age is called complementary food. The main aim of complementary food is to fill the gap between the nutrient needs of the child and that contained in breast-milk. This transition period helps the child to slowly become accustomed to eating adult-type foods and familiarizes the child with a wide range of textures and tastes. The adequacy of complementary food not only depends on the availability of a variety of foods in the household, but also on the feeding practices of caregivers (WHO, 2005). Feeding young infants requires active care and stimulation, where the caregiver is responsive to the child clues for hunger and also encourages the child to eat. This practice is referred to as active or responsive feeding. WHO (2005) recommended that infants start receiving complementary foods at 6 months of age in addition to breast milk, initially 2-3 times a day between 6-8 months, increasing to 3-4 times daily between 9-11 months and 12-24 months with additional nutritious snacks offered 1-2 times per day, as desired.
In 1979, a joint WHO/UNICEF expert consultation on Infant and Young Child Feeding recommended the promotion and support of appropriate and timely complementary feeding practices by using local food resources. In 2008, another WHO/UNICEF expert consultation recognized that the evidence for effective interventions to improve feeding in children 6-23months of age although has been strengthened considerably in recent years but evidence for what works to improve the utilization and intake of adequate complementary foods remains limited. They recommended among other things, increasing dietary diversity by using locally available nutritious food as an effective approach to improve the quality of young children’s diet. This is especially so for the poorest groups of the population who have no access to appropriately fortified food products and or cannot afford point- of use fortification or enrichment of the local diets (WHO/UNICEF, 2008).
Most infants begin the transition from liquid to solid foods with the introduction of commercial infant cereals, which when complemented with breast milk or formula can be a good starting place. In most developing countries however, the high cost of these nutritious complementary foods is always if not culturally prohibitive, or beyond the reach of most families. Such families often depend on inadequately processed traditional complementary foods consisting mainly of unsupplemented cereal porridges made from rice (Oryza sativa), wheat (Triticum spp.), maize (Zea mays), sorghum (Sorghum bicolor) and millet (Pennisetum americanum). In view of this, a number of cereals and legumes that are readily available in Nigeria have been found to have nutrients potentials that could complement one another if properly processed and blended (Fernan & Vanderiart, 1996). Such blends have been found to improve nutrient density and intake, thereby resulting in the prevention of nutritional problems (Nwamarah & Amadi, 2009). Some of these indigenous cereals for example fonio/acha (Digitaria exilis) and legumes such as sesame seed (Sesamum indicum) are still under exploited for use in complementary feeding. The improvement in infant nutrition using these locally available foods is desirable not only because of the positive impact on physical growth and development of the infant but to stem off malnutrition and its complications.
1.2 Statement of the problem
Childhood undernutrition remains a major public health problem in resource-poor settings (WHO, 2003). WHO (2011) estimates that 2 out of 5 children less than five years of age in developing countries are stunted (low height-for-age), and large proportions are also deficient in one or more micronutrients. Globally, 30% (or 186 million) of children under five are estimated to be stunted and 18% (or 115 million) have low weight-for-height, mostly as a consequence of poor feeding and repeated infections, while 43 million are overweight. Few children receive nutritionally adequate and safe complementary foods; in many countries only a third of breastfed infants 6-23 months of age meet the criteria of dietary diversity and feeding frequency that are appropriate for their age (UNICEF, 2008). It is well recognized that the period from birth to two years of age is the “critical window” for the promotion of optimal growth, health, and development. Insufficient quantities and inadequate quality of complementary foods, poor child-feeding practices and high rates of infections have a detrimental impact on health and growth in these important years (WHO, 1998). Even with optimum breastfeeding children will become malnourished if they do not receive sufficient quantities of quality complementary foods after six months of age (WHO, 2005). An estimated 6% or 600,000 under-five deaths can be prevented by ensuring optimal complementary feeding (WHO, 2011). Optimal breastfeeding and complementary feeding practices can save the lives of 1.5 million children under five every year (WHO, 2010).
Low-quality complementary foods (plant based) combined with inappropriate feeding practices predispose children in developing countries (including Nigeria) to high risk for malnutrition and its associated outcomes (WHO, 2003). Studies have shown that, solid and semi-solid foods are introduced too soon or too late in some cases; also, the frequency and amount of food offered may be less than required for normal child growth, or their consistency or nutrient density may be inappropriate in relation to the child’s needs. Poor complementary food could displace the more nutritive breast milk in the child’s diet, if complementary feeding is introduced before 6 months. Other problems associated with plant-based infant complementary food include bulkiness, low energy, low nutrient densities and monotony of the diets (Ibeanu, 2009).
Low or poor quality protein content and monotony of traditional complementary foods are still problems to mothers who cannot afford to complement these traditional complementary foods with animal protein sources. Commercial complementary food enriched to meet infant’s nutrient requirements are expensive and out of the reach of the poor.
These problems compromise the health, growth and development of infants thereby predisposing them to Protein – Energy Malnutrition (PEM) and infections. Therefore there is need to explore ways of increasing the nutritional quality of cereals and legumes Infants and young children are very vulnerable to foodborne illness (Duyff, 2007).Their immune system are not developed enough to fight food borne infections, therefore Safe preparation and storage of complementary foods is very important. Hence there is need to process their food to ensure shelf life stability for future use.
Some indigenous legumes and cereals in Nigeria, which are cheap sources of plant protein are under exploited and rarely used for infant feeding. Maize (Zea mays), rice (Oryza sativa), and in recent time wheat (Triticum spp.), soybean (Glycine max) and peanuts (Arachis hypogea) are widely used for complementary feeding, other cereals and legumes such as acha (Digitaria exilis), and benne seed (Sesamum indicium) are not commonly used in infant feeding. Thus as part of the attempts toward improving the nutritional quality of plant foods, the potentials of these underutilized staples to produce multi mixes for use in complementary feeding could be exploited as cheap and nutritionally adequate alternative to the monotonous maize or millet pap.
1.3 Objectives of the study
The general objective of this study was to evaluate the chemical composition, nutrient adequacy, shelf-life and organoleptic properties of formulated infant complementary food based on acha (Digitaria exilis), sesame seed (Sesamum indicum), and soybean (Glycine max). The specific objectives of the study were to:
- determine the chemical composition (proximate, minerals, vitamins and photochemical) of processed flours from acha, benne seed and soybean;
- formulate complementary mixes from the flours based on protein composition;
- assess the nutritional adequacy of the formulated complementary mixes;
- determine shelf life qualities (free fatty acids, pH, water activity and microbial activities of formulated complementary mixes) and
- assess the organoleptic properties of porridge prepared from formulated complementary mixes.
1.4 Significance of the study
The result of this study will be of use to mothers, Nutritionist, Dietitians, Food Scientists, Health educators, Doctors, Nurses, maternal and child workers, community health workers and other related professionals. The information in this study would be of benefit to mothers who desire to prepare nutritionally adequate diet for their infants using locally available staples. The information from the study could also be used by mothers or caregivers, Nutritionists, Dietitians and other health workers, to promote dietary diversity using locally available nutritious staples; hence add variety to infants’ diet. The result of the study might lead to the production of local instant pre-cooked and dehydrated infant complementary foods that will be familiar and easy for mothers and caregivers to reconstitute with boiled water. The result of the study would assist Nutritionist, Dietitians, Community and health workers and other related professionals to educate, counsel and offer clear guidelines to mothers and caregivers as a whole on how to provide adequate diets for infants from locally available food crops. It might also aid food scientist in their bid to develop instant infant food using such locally available grains. The shelf-life study can provide important information to product developers enabling them to ensure that the consumer will get a high quality product for a significant period of time after production.