Nutritional evaluation of complementary porridge formulated from orange‐fleshed sweet potato, amaranth grain, pumpkin seed, and soybean flours

Abstract Supplementing breastmilk with poor energy and nutrient‐dense complementary foodstuffs for young children and infants has resulted in malnutrition, poor growth, and retardation of infant development in many sub‐Saharan African countries. Ensuring nutrient adequacy for infants because of their lower consumption requires energy and nutrient‐dense food. In this context, the nutritional composition of porridge from complementary flour blends of locally available foodstuffs (orange‐fleshed sweet potato, pumpkin seeds, amaranth grains, and soybeans) was carried out. Complementary flours formulated from flour blends of pumpkin seeds, extrusion cooked soybean, and orange‐fleshed sweet potato, as well as germinated and extrusion cooked amaranth grains, resulted in varieties of complementary porridges (SAPO1–SAPO5). From these, proximate composition, mineral content (sodium, iron, magnesium, calcium, phosphorus, and zinc), vitamin contents (A and C), and nutrient density of the formulated complementary porridge were determined. Results showed that all the formulated complementary porridge were able to meet the stipulated standards of energy and nutrient (zinc, iron, vitamin A, and protein) densities. Flour blend ratio, germination process, and extrusion cooking significantly (p < .05) influenced the targeted nutrients of interest, as well as the nutrient and energy densities of the formulated complementary porridge. Specifically, the formulated complementary porridge with 40% amaranth grain, 25% orange‐fleshed sweet potato, 20% soybean, and 15% pumpkin seed composite mixture had 76.92% compliance level with recommended standards, which assure adequate nutrient complementation to breastfeeding. The present study provides a valuable insight that complementary foods from locally obtainable foodstuffs are potential solutions for mitigating childhood malnutrition and adequate complementation to breastfeeding by proffering the needed energy and nutrient densities required for the immunity, well‐being, growth, and development of young children and infants, without fortification.


| INTRODUC TI ON
The conventional method of breastfeeding provides the infant with several benefits such as a sufficient supply of nutrients, rapid growth, healthier and active lifestyle, and reduced risk of diseases and infant mortality (Oladiran & Emmambux, 2020). However, after 6 months of exclusive and frequent breastfeeding, infants and young children should be provided with complementary foods that are rich in energy and nutrients since their nutrient requirements can no longer be met from human breastmilk only (Agbemafle et al., 2020;Alamu et al., 2018;Ekesa et al., 2019;Tenagashaw et al., 2017;UNICEF, 2020;WHO, 2013). Complementary foods are referred to as energy and nutrient-rich semisolid or pureed foodstuffs given to infants in addition to human milk and infant formula (Demmer et al., 2018;Kleinman, 2014). They are well known as a combined formulation of various foods developed to supply nutrients (rich in carbohydrates, lean protein, healthy fat, minerals, and vitamins) obtained from various sources including legumes, cereals, vegetables, and fruits, which are critical for healthy living of young children (Abamecha, 2020;Abeshu et al., 2016;WHO, 1998). Complementary feeding aims to ensure that in the long run, the child consumes the same well-balanced and nutritious mixed diet of "family foods" (Demmer et al., 2018;Kleinman, 2014). This is a key step in the development of the eating behavior and affects directly the health and growth of an infant (Demmer et al., 2018;Greer et al., 2008).
On a global scale, one hundred and forty million children of less than five years are stunted (low height for age), and over forty-seven million are still impacted with wasting (low weight for height), particularly during the period of complementary feeding (Agbemafle et al., 2020;UNICEF, 2020). The triple burden of malnutrition mostly affects Africa as a continent, with 30 countries suffering micronutrient malnutrition, undernutrition, and overweight (Development Initiatives, 2018;Low et al., 2020). Sub-Saharan Africa experiences a micronutrient deficiency of as high as 49% among households (Emmaculate et al., 2020;Fraval et al., 2019). The most serious health challenge in developing countries is undernutrition, with Tanzania having the highest risk of undernutrition in the Eastern and Southern Africa. The main causes for undernutrition have been identified as poor feeding practices of infant and young child (Khamis et al., 2019). Interestingly, undernutrition is a major obstacle that prevents young children from reaching their full developmental potential and is responsible for at least 35% of mortality in children from developing countries (WHO, 2009). Undernutrition in infants and young children can be lessened by improving the feeding practices by providing appropriate nutrient-rich foodstuffs (Agbai et al., 2021;Black et al., 2013;Ekesa et al., 2019;McCormick et al., 2019). Malnutrition/undernutrition is predominantly caused by inadequate dietary intake and micronutrient deficiency (Bailey et al., 2015). Importantly, the problem of malnutrition in many infants starts during or after the introduction of complementary foods, significantly contributing to an increased occurrence of malnourishment in children of less than five years (Mosha et al., 2000;Muhimbula & Zacharia, 2010). As most complementary foods in many developing African nations are predominantly poor nutritional cereal-based foods (Dimaria et al., 2018;Pelto et al., 2003), malnutrition is inevitable as these traditional weaning foods are primarily starchy foods that are high in energy content, viscosity, bulk density, poor in protein quality, and generally low in nutrients (Eke-Ejiofor et al., 2021). Thus, the appropriate progression from exclusive infant breastfeeding to complete utilization of complementary foods for weaning purposes can only be achieved when adequate, timely, safe, and appropriate amounts of complementary foods are provided to the young children as this promotes their good nutritional status and growth (Alamu et al., 2018;Eke-Ejiofor et al., 2021;Ijarotimi & Keshinro, 2013;Issaka et al., 2015).
In consonance with many of the sub-Saharan African households utilizing cereal-based flours to prepare most of their staple foods, the micronutrient composition of these cereal-based flours is low with higher quantities of antinutritional components (Emmaculate et al., 2020;Fraval et al., 2019). Tanzania, as one of the developing countries in Africa, depends on weaning foodstuffs that are obtained from locally available staple foods, especially cereals (Mamiro et al., 2005;Muhimbula & Zacharia, 2010;, thereby causing a high rate of childhood undernutrition (Mosha et al., 2000). However, the commercial weaning foods, which are trusted to be nutritive and fortified, are usually not available in the rural areas, and where available, they are far from being accessed by many households due to their exorbitant prices (Dewey & Brown, 2003). Similarly, the availability of good sources of protein such as meat, eggs, milk, and fish is limited due to their high costs in the households of many developing countries, prompting the need to improve the nutritional content of the readily obtainable cereals (Emmaculate et al., 2020;Manary & Callaghan-Gillespie, 2020). It is well known that agricultural practices, and climatic, socioeconomic, cultural, and ecological factors determine to a great extent the availability of foods in a given region, dietary pattern, and well-being of the people (Caswell & Yaktine, 2013;Singh & Singh, 2017;Tandzi & Matengwa, 2020). Given this, the type of complementary foods fed to young children and infants in most rural communities in Africa is poised with intrinsic nutritional gaps. Besides insufficient nutrient density for vitamins A and C in most indigenously made complementary foods, the most limiting nutrients are calcium, zinc, and iron Vossenaar et al., 2013). Though calcium is not a major concern because it could be obtained from breastmilk, the sources of zinc and iron K E Y W O R D S complementary feeding, iron availability, limiting nutrients, malnutrition, micronutrient density, zinc availability are found dearth which are essential for normal growth, hematopoiesis, and neurologic and cognitive developments in infants (Krebs, 2000;Seth & Garg, 2011). Studies have shown that over 85% of complementary foods fed to infants aged 6-11 months failed to meet the WHO-recommended nutrient density levels for zinc and iron (Ferguson & Darmon, 2007;Tenagashaw et al., 2017).
The complementary foods on which these children are fed in the developing nations have been recounted to be unable to meet their nutrient requirements in both quality and quantity (Okoth, 2020;Webb et al., 2018). Due to poor quality complementary foods that contribute to undernutrition, there is an underlying need to develop nutrient-dense complementary food that can meet the nutrient requirements of children aged 6-33 months (Okoth, 2020).
To reiterate, malnutrition is not only caused by lack of food but also by inadequate knowledge and exposure on the utilization of suitable available nutrient-dense foods for infant feeding. Despite the efforts made by the UN's Sustainable Development Goals and the Millennium Development Goals to eradicate (hidden and visible) hunger, malnutrition is still prevalent in most developing nations in Africa. With regard to infant feeding, the limitations of formulating complementary foods with only cereal-based foods cannot be overemphasized as it assures nutritional imbalance, thereby giving rise to malnutrition. Though cereal-based complementary foods form a vital source of nutrients for many of the infants in rural communities of low-and middle-income states, developing a framework to help improve the nutrient density of such weaning food cost-effectively is important. One essential approach to curb the limitations associated with the locally formulated complementary food is composting cereals with legumes and/or fruits or vegetables (Oladiran & Emmambux, 2020). In addition to composting, processing treatments and techniques have demonstrated a high promise in improving the nutritional properties of food. Moreover, multiple studies have shown that processing applications and treatment of legumes and cereals not only extend the shelf life of the product but also enhance nutrient availability, reduce antinutrients, and improve the rheological and flavor attributes of the product (Eke-Ejiofor et al., 2021;Nwosu et al., 2019). Examples of such processing treatments may include but are not limited to extrusion cooking, soaking, pregelatinization, germination/malting/sprouting, and nonthermal processes Ofoedu et al., 2020;Osuji et al., 2019). Some of these processing treatments reduce or eliminate antinutritional factors and enhance digestibility and nutrient availability.
Furthermore, as breastfeeding cannot provide the nutrient necessities of a growing child (≥6 months), the World Health Organization recommends reducing childhood malnutrition sustainably by using available indigenous foodstuffs such as amaranth grains, to formulate energy and nutrient-dense complementary foodstuffs that are nutritionally and hygienically adequate (Abeshu et al., 2016;Agbemafle et al., 2020;Khamis et al., 2019;WHO, 2008). Consequently, there has been an increase in research interest, especially in sub-Saharan Africa with an emphasis on developing complementary foods from locally available materials (Okoth, 2020;Osendarp et al., 2016).
Given this, exploring the available opportunities of incorporating locally available nutrient-dense and diverse ingredients in complementary feeding to enhance the nutrient content of complementary foodstuffs in Tanzania is very fitting. Although Dendegh et al. (2021) evaluated stiff porridge from composite flour blends of African yam bean and pearl millet, Gemede (2020) evaluated complementary foods developed from pea, maize, and anchote flours, and Eke-Ejiofor et al. (2021) reported the formulation of complementary food from a mixture of millet (malted and unmalted), African yam bean, and jack fruit flour blends; pertinent literature on porridges of complementary foods formulated from flour combinations of orange-fleshed sweet potato, pumpkin seeds, amaranth grains, and soybeans is still scanty. Specifically, it is imperative to formulate a balanced nutrientdense complementary foodstuff from the aforementioned locally available foodstuffs using some processing techniques (soaking, germination, and extrusion cooking). In addition to that, the evidence of acceptable complementary porridge flour for weaning purposes, rich in nutrients, would demonstrate the value addition and potential the use of locally available foodstuffs would bring toward diversification of products in the weaning food industry. In this context, therefore, the nutritional composition of porridge from complementary flour blends of orange-fleshed sweet potato, pumpkin seeds, amaranth grains, and soybeans was carried out. The developed product was expected to contribute to improving the macro-and micronutrient excellence of the complementary porridges used in Tanzania.

| Experimental schematic overview
The schematic overview of the experimental program as shown in

| Procurement of raw materials
Orange-fleshed sweet potato, pumpkin seeds, soybean, and amaranth grains were purchased from Morogoro market, Morogoro Region, Tanzania. These raw materials were selected because of their richness in the targeted nutrients (vitamin A in the form of β-carotene, zinc, iron, energy, and protein) as reflected in literature. The food-grade chemicals and reagents used in this study were obtained from the laboratory of the Department of Food Science and Agroprocessing (formerly the Department of Food Technology, Nutrition and Consumer Sciences), Sokoine University of Agriculture, Tanzania.

| Sample preparation
The raw materials (orange-fleshed sweet potatoes, pumpkin seeds, soybeans, and amaranth grains) were processed and prepared to Similarly, soybean grains were washed, boiled for about 25 min to inactivate trypsin and soften the cotyledons for easy dehulling, cooled, dehulled manually, dried in a hot air oven, extruded, and milled to flour. Also, amaranth grains were washed, steeped in water for 18 h, and germinated for 24 h to enhance digestibility and nutrient bioavailability. Subsequently, the germinated grains were washed, dried in a hot air oven, and extruded, followed by milling to flour. On the contrary, the pumpkin seeds were washed, soaked in water for 24 h to

| Formulation of flour blends
Flours from orange-fleshed sweet potatoes, pumpkin seeds, soybeans, and amaranth grains were blended in different proportions as presented in programming was used to optimize the flour blends that would yield an acceptable limit of the target nutrients. Subsequently, the complementary flours that met (at least) half of the targeted nutrients' RDA were selected and progressed to porridge preparation. Therefore, from the treatment combinations, five samples were generated with the aid of the software. In other words, a combination of these ingredients (orange-fleshed sweet potatoes + pumpkin seeds + soybeans + amaranth grains = 100%) was therefore expected to give a nutritionally balanced complementary food.

| Porridge preparation
Five composite flours (SAPO1-SAPO5) from different blends of orange-fleshed sweet potatoes, pumpkin seeds, soybeans, and amaranth grains (Table 1) were used to prepare porridges by mixing 350 g of flour in 1500 ml of boiling water with continuous stirring for about 15 min until the porridge was cooked. Additionally, two commercial formulations (reference/control samples) were also prepared in the same manner as described above. Importantly, the reference sample SOS was a blend of soybeans, orange-fleshed sweet potatoes, and sorghum flours, while SMGM was a blend of soybeans, maize, groundnuts, and millet flours.

| Determination of proximate composition
The proximate composition (protein, fat, crude fiber, and moisture content) of the ingredients and the prepared porridge from complementary flours was determined according to the method described by AOAC (2012) while carbohydrate was determined by difference as shown below. To calculate the gross energy content from carbohydrate, protein, and fat contents, the conversion factors (4 kcal/g for carbohydrate, 4 kcal/g for protein, and 9 kcal/g for fat) were used (Guyot et al., 2007).

| Determination of vitamin C and β-carotene
Vitamin C content of the complementary porridge flour was determined using the titration method according to Tomohiro (1990) by titrating the extract from a mixture of flour sample (2 g) and 10% trichloroacetic acid (TCA) solution against a standard solution of 2,6-dichlorophenolindophenol sodium salt. The amount of vitamin C content expressed as mg/100g was calculated using the formula below: where A is the volume in ml of the Indophenols solution used for the sample, B is the volume in ml of the indophenols solution used for blank, C is the mass in mg of ascorbic acid equivalent to 1.0 ml indophenols solution, S is the mass of sample in (g) taken for analysis, and V is the total volume of extract in milliliters On the contrary, β-carotene was determined using the method described by AOAC (2003), which involved homogenization of sample (5 g) in an acetone solution, followed by filtration (1) 2.6.4 | Determination of energy and nutrient density The energy and nutrient density of porridges from formulated complementary flours were determined according to the methods described by WHO/UNICEF (1998) and Tenagashaw et al. (2017).
Importantly, the amount of food consumed by young children (>6 months old) was estimated to be 195 ml. The energy density (expressed as Kcal/g) and nutrient density were calculated as follows:

| Statistical analysis
Statistical analyses were carried out using IBM SPSS software version 20 (IBM Corp., New York, USA). The assumptions of analysis of variance (ANOVA) were investigated for normality, outliers, and homogeneity of variances using kurtosis, box plot, and Levene's test.
Data obtained from duplicate determinations of the sample were subjected to a one-way ANOVA. Results of the parameters determined were expressed as mean ±standard deviation (SD), and the mean differences were resolved using Tukey's honest significant difference post hoc test with the significance level set at 95% (p < .05) confidence level.
The moisture content of flour is used as an indicator of quality, since it is considered as an important factor that impacts storage, shelf life, and safety of foods (Ibeabuchi et al., 2017;Gemede, 2020). The moisture content of ingredients' flours was significantly lower (p < .05) than the specified limits (14% or less) for flour moisture (Simsek, 2020). Low moisture content of flours suggests extended shelf stability as a result of prolonged drying or high drying temperature (Ibeabuchi et al., 2020;Osuji et al., 2019).
However, the ash content obtained in this study from all the selected ingredients is significantly higher (p < .05) than the values of 2.54%-3.87% reported by Gemede (2020) for pea, maize, and anchote flours. Ash is the mineral constituent in flour (Ihediohanma et al., 2014;Nwosu, Odimegwu, et al., 2014). Thus, the highest ash content of given flours may be able to meet the minimum requirements of limiting minerals in typical locally made complementary foods. The value of fiber content of ingredients' flours was significantly higher (p < .05) than 0.50% reported by Osuji et al. (2019) for rice flour, and was higher than 1.92% and 2.51% reported by Gemede (2020)

| Proximate composition of the formulated complementary porridges
The proximate composition of the formulated porridge is shown in  (Achidi et al., 2016;Adisetu et al., 2017).
Common protein deficiency outcomes include stunting and wasting, with stunting being linked with hindered motor growth, weakened social productivity, and meager cognitive and school performance (Agbemafle et al., 2020;Bhutta et al., 2013).
The crude fat content of the formulated complementary porridges was significantly higher (p < .05) compared with the control samples (SOS and SMGM). As can be seen from  Similarly, the crude ash content of the formulated complementary porridges was higher compared with that in the control samples (SOS and SMGM), which was significantly lower (less than 6%) but within the acceptable recommended Codex standard (<5%).
In a similar study, a significantly higher amount of ash (2.71%) was recorded for the highly regarded formulated complementary food compared with the control samples (Lyarea et al., 2018). Another study further recorded the ash content of formulated complementary food as ranging from 1.26% to 2.31% (Olatunde et al., 2020).
Ash content signifies the presence of minerals in food samples (Laryea et al., 2018;Owiredu et al., 2013), and this denotes that the formulated complementary foods in this study are potential sources of minerals (Table 5). The findings from this study reflect findings by Haque et al. (2013) that the proportion of soybean (at least 20% as shown in Table 1) resulted in high ash content of soybean flour as one of the ingredients (

| Mineral content of the ingredients
The mineral composition of the ingredients is shown in  Hurrel, 2004). Iron is essential in an infant diet for hemoglobin synthesis and their mental and physical welfare as its deficiency adversely impacts the growth of infants during the weaning period (Laryea et al., 2018). can provide at least 50% of zinc DRI, which is considered sufficient (Adisetu et al., 2017;Codex, 2010). Therefore, the porridges are considered suitable for use by the targeted group, which includes children and women of reproductive age. Similar to iron, zinc deficiency is also associated with stunting, anemia, and higher disease susceptibility (Agbemafle et al., 2020;Bhutta et al., 2013). It can result to permanent defects in immune function, motor, and cognitive development, as well as academic and behavioral performance (Adisetu et al., 2017;Brown, 2009).
The magnesium levels of the formulated complementary porridges were similarly significantly higher (p < .05) when compared to both the control samples and the DRI (54-75 mg/100 g). The higher magnesium content of formulated diets is evidently due to the raw materials utilized in complementary food formulation (Table 4). Kolawole et al. (2020) emphasized that 10% soybean, in addition to a complementary formulated food containing 10% OFSP, increased the magnesium content, indicating that soybean is a good source of the mineral. Magnesium is crucial for good infant health as it keeps the heart rhythm steady, strengthens the bones, supports a healthy immune system, and maintains normal muscle and nerve function (Ndife et al., 2020).

| Vitamin content of the formulated porridges
The vitamins A and C content of complementary porridge ranged from 180.50 to 232.20 µg RE/100g and 1.60 to 7.80 mg/100 g, respectively ( Table 6).
The porridges of formulated complementary flours (SAPO1-SAPO5) had the vitamin C content ranging from 1.60 to 7.80 mg/100 g while the reference (control) samples (SOS and SMGM) recorded the vitamin C contents of 1.60 mg/100 g and 2.20 mg/100 g, respectively. However, the vitamin A content of the complementary porridge (SAPO1-SAPO5) ranged from 180.50 to 232.20 µg RE/100 g while the reference samples (SOS and SMGM) had a vitamin A content of 215.50 µg RE/100 g and 148.50 µg RE/100 g, respectively.
The presence and adequacy of vitamins A and C in complementary foods cannot be overemphasized. Generally, vitamins are important nutrients that are essential for optimal health across the life cycle (Hill, 2020).
Results show that SAPO4 had a higher vitamin C content among the formulated complementary porridges though not significantly different (p > .05) from SAPO5, while SAPO1 recorded the least vitamin C content. The higher vitamin C in SAPO4 and SAPO5 could be due to the increased amount of orange-fleshed sweet potato flour in its formulation. Besides dietary fiber and essential minerals, orange-fleshed sweet potato is a rich source of vitamin C in the form of ascorbic acid (Korese et al., 2021;Van, 2000). Specifically, vitamin C is a water-soluble micronutrient that plays a vital role in an infant's physiological functions such as facilitating collagen production, maintaining a healthy immune system, and enhancing iron absorption (Hill, 2020;. Unlike many micronutrients, vitamin C is unique because of its antioxidant capacity, which helps protect cells from free radical damage (Ofoedu, You, et al., 2021). In this study, though porridges from complemen- On the contrary, SAPO4 had the higher vitamin A content followed by SAPO5 while SAPO1 recorded the least vitamin A content of 180.50 µg RE/100 g. The variations could be as a result of the proportions of soybean and pumpkin seed in the formulation.
Soybean and pumpkin seeds are well known as oil seeds with fat contents of 22.30% and 43.46%, respectively (Table 2), thereby suggesting adequate dissolution of lipophilic vitamins such as vitamin A . Moreover, vitamin A is a fatsoluble micronutrient that is crucial for rapid growth and fighting infections (UNICEF, 2019), as its insufficiency has been implicated to be the leading cause of visual impairment (night blindness) and high risk of deaths from common illness in children such as diarrhea .  (Burri, 2011;Korese et al., 2021;Van, 2000). This corroborates the findings of Waized et al. (2015), which reported that in most OFSP species, a small amount of only  (Table 6).

| Energy and nutrient density of the formulated porridges
The energy and nutrient density of complementary porridge is presented in Table 7.
The variations in energy densities of previously mentioned studies, when compared to the current study, might be as a result of the difference in raw materials (ingredients) and the processing methods.
In this study, soybean and pumpkin seeds with high-fat content of 22.30% and 43.46%, respectively (  (Amagloh et al., 2013). The energy density of complementary food is well known as a determinant of the quantity of food needed to meet the energy needs of infants (Oladiran & Emmambux, 2020).
In other words, while a large amount of a low energy-dense foodstuff is required for complementary feeding, a smaller amount of an energy-dense foodstuff would be necessary to be fed to an infant.
The formulated complementary porridge (SAPO1-SAPO5) had a protein density ranging from 0.64 to 1.05 g/100 Kcal while the reference (control) samples (SOS and SMGM) recorded a protein density of 0.34 g/100 Kcal and 0.38 g/100 Kcal, respectively (Table 7). The protein density of the formulated complementary porridge is significantly higher (p < .05) than in the reference samples. Importantly, the overall effect on protein quality is dependent on ingredient composition and the processing treatments used, as germination and extrusion conditions may have influenced the properties of the complementary porridge. Germination has been reported to increase the protein quality of food (Ofoedu, Akosim, et al., 2021;Ofoedu et al., 2019Ofoedu et al., , 2020Okafor et al., 2018;Osuji et al., 2019Osuji et al., , 2020. Similarly, extrusion cooking has also been demonstrated to increase lysine availability and protein digestibility (via reduction of antinutritional factors) due to the unfolding of protein molecules (Aryee et al., 2018). Low protein density in complementary food suggests that such food may not be able to supply all the required essential amino acids in the right proportion, thus resulting in food with low protein quality. shielding it from thermal degradation resulting from extrusion cooking (Kapusniak & Tomasik, 2006). Lipids are known to enhance the absorption of vitamin A and other fat-soluble vitamins (WHO, 2009) and also enhance the encapsulation of other solid components in food (Ozkan et al., 2020).
The complementary porridge densities of iron and zinc, which are considered "problematic" nutrients in children and infants' food in developing nations, were met, except for SAPO4 (Table 7). Thus, this study proposes that the complementary porridges are good sources of iron and zinc. The considerably high iron density in the formulated complementary porridge could be due to the significant reduction in antinutrients that are potential iron inhibitors such as phytates, by extrusion cooking. Additionally, the concentration of vitamin C may be such that enhanced iron absorption, in which case the complementary porridges are considered to have iron bioavailability (Ruel et al., 2004). Zinc is particularly an important nutrient for the growth and immune function of infants and young children. Just like iron, the amount of zinc in breastmilk is low after the infant is about 6 months of age. Unlike many indigenous complementary porridges, the formulated diet in this study is a typical candidate for zinc, as the porridges were able to meet the minimum requirement of zinc density according to WHO/UNICEF (1998) and WHO (2002). However, there seems to be a positive correlation between iron density and zinc density. According to Brown and Lutter (2000), diets that are high in bioavailable iron are also likely to be high in bioavailable zinc, as both micronutrients are contained in similar foods.
Furthermore, Table 8 briefly shows the compliance or noncompliance of the formulated complementary porridges to recommended standard levels.
Overall, all the formulated complementary porridges were able to meet the stipulated standards of energy and nutrient (protein, vitamin A, zinc, and iron) densities except for SAPO4 that could not meet the recommended standard of iron density. Although SAPO4 met the recommended vitamin A acceptable limit, it could not meet that of phosphorus. While none of the formulated diets met calcium and the vitamin C content, all of them exceeded the acceptable limit of sodium. From the results, SAPO5 has the highest percentage compliance (76.92%), which is indicative of its high promise in offering the limiting nutrients required in complementary diets. Therefore, SAPO5 porridge can serve as a key diet for adequate complementation of breastfeeding among other formulated complementary porridges.

| CON CLUS ION
In this study, the nutritional composition of the formulated com-  Note: Keys: +: met the recommended standard level or fell within the acceptable limit.
-: Failed to meet the recommended standard level or fell outside the acceptable limit.

ACK N OWLED G M ENT
This work was supported by the Innovative Agricultural Research Initiative (iAGRI) and Regional University for Capacity Building in Agriculture (RUFORUM).

CO N FLI C T O F I NTE R E S T
The authors declare no conflict of interest.

E TH I C S A PPROVA L
The study does not involve any human or animal testing.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon request.