Key findings:

Key findings from this study on formulating weaning food include: the use of yellow corn, tigernut, and date fruits to create fortified pap with enhanced proximate, mineral, and vitamin content; microbial analysis revealed various isolates present, with Total Viable Bacterial Count (TVBC) and Total Fungal Count within acceptable limits, demonstrating improved nutritional and microbiological quality of the weaning food.

What is known and what is new?

The known aspect in this abstract is the formulation of weaning foods using diverse raw materials for infant nutrition. The new contribution is the utilization of yellow corn, tigernut, and date fruits to create fortified weaning food with improved proximate, mineral, vitamin content, and enhanced microbiological quality, showcasing the potential for cost-effective and nutritious infant feeding options.

What is the implication, and what should change now?

The implication of this study is the potential of using locally available and affordable raw materials like yellow corn, tigernut, and date fruits to formulate nutritious and safe weaning foods. Changes needed include further research to optimize the formulation, explore additional nutrient-dense ingredients, and ensure consistent quality and safety standards for large-scale production and distribution of these weaning foods

Weaning is the stage when an infant moves from a diet consisting exclusively of breast milk to one which resembles that of an adult in the community. It is the process of introducing semi-solid food into the infant diet [1]. The growth of the infant in the first or second year is very rapid and breast feeding alone will not meet the child nutritional requirements. 

The process of weaning an infant marks the transition from an exclusively milk diet to one containing predominantly semisolid food [2]. Weaning food ought to be rich in protein which is in short supply in most parts of Nigeria particularly in rural areas. These foods when eaten in large quantities provide considerable energy but the quality of the protein is low particularly for the growing infant.

In most rural areas, combinations of different legumes, cereal grains, seeds and nuts are used in preparing weaning food for babies. The essence of supplementing most cereals with nuts is to improve their protein composition as well as other nutritional and proximate properties. Among these include; yellow corn, tigernut and dates. Yellow corn or maize (Zea mays L.) is an annual monocotyledonous diploid belonging to the Poaceae family and the Mayolae tribe of which eight different genera have been recognized by taxonomy. 

Tigernut (Cyperus esculentus) is a perennial grass-like plant with spheroid tubers, pale yellow cream kernel surrounded by a fibrous sheath. It is locally called “aya'' in Hausa, “aki awusa” in Igbo, “ofio” in Yoruba, “isi paccara” in Efik. Tigernut are edible, sweet, nutty, flavored tubers which contain protein, carbohydrate, sugar and lots of oil and fiber. 

Dates are a kernel surrounded by a fleshy pulp that is rich in fiber, vitamins and minerals. Good dates are eaten locally or packaged in factories and often shipped abroad; the poor ones are fed to cattle.

Hence, this study was aimed at formulating a weaning food  using locally available and cheap raw materials such as yellow corn, tigernut and date fruits and study the  proximate, mineral, vitamin and microbiological quality of locally formulated weaning food produced from yellow corn tigernut and date fruit

Chemicals and Reagents:

All chemicals and reagents used were of analytical grade.

Sample Collection:

Yellow corn, date fruits and tigernut were purchased from Nkwo-Ukwu Ihiagwa market, Owerri-West, L.G.A, Imo State, Nigeria and were taken to the laboratory for fermentation, formulation of weaning food and determination of the proximate, mineral composition and microbial qualities.

Processing of Yellow Corn, Date Fruits and Tigernut for Production of Weaning Food:

The methods described by (Association of Official Analytical Chemists (AOAC). 2005; Okafor, U. I. et al., 2018) [3, 4] were adopted in the processing of the grains and nuts into weaning food. The date fruits were soaked in clean water to soften the fruits and the fruits were broken and the seeds were removed. The tigernut and yellow corn were sorted and washed using clean water separately. The yellow corn was steeped in clean water for 72 hours for fermentation. The softened grains of yellow corn, date fruits and tigernut were ground in a mechanized milling machine. The ground slurry was rinsed with water and passed through a sieve (muslin cloth) to remove parts of the hull. The filtrate, almost pure starch was placed in pots of water to settle and was covered up completely for laboratory analysis.

Yellow corn

Sorting

Washing thoroughly in water

Steeping in tap water for 72 hours at 27 ⁰C

Washing 

Addition of tigernut and date fruits

Wet milling

Wet sieving

Weaning food (pap) 

Figure 1: Flow chart showing production of weaning food from yellow corn, tigernut and date fruits [4].

Determination of Proximate Compositions of the Formulated Weaning Food:

The proximate composition of the weaning food produced from yellow corn, date fruits and tigernut was analyzed for the following parameters: Ash content, protein content, crude fibre content, crude fat content, moisture content and carbohydrate content using the method described by (Association of Official Analytical Chemists (AOAC). 2005) [3].

Determination of Mineral Contents of the Weaning Food:

The mineral contents were determined after the ash content determination. The ash residue of the formulation was digested with perchloric acid and nitric acid (1:4) solution. The samples were left to cool and contents were filtered through Whatmann’s No. 42 filter paper. The sample solution was made up to a final volume of 25 ml with distilled water. The aliquot was used separately to determine the mineral contents such as Zinc, Magnesium, Iron, Calcium and Potassium by using an Atomic Absorption Spectrometer (Spectra AA 220, USA Varian) [5].

Determination of Vitamin Contents of the Weaning Food:

The methods of (Association of Official Analytical Chemists (AOAC). 2005) [3] were adopted in the determination of the vitamin contents (vitamins B₂, B₃ and C) of the formulated weaning food. 

Microbiological Analysis:

The microbiological quality of the formulated weaning food from yellow corn, date fruits and tigernut was determined using standard microbiological methods. The method described by (Ogodo, A. C. et al., 2015) [6] was adopted. Exactly 1g of the weaning food was added to 9.0 milliliters of sterile water in a test tube and ten-fold serial dilutions were made. Thereafter, 0.1ml from the test tube labeled 10^-3 was aseptically plated using pour plate technique for total viable aerobic bacteria count on nutrient agar (Biotech), eosin methylene blue agar and total fungal count on sabouraud dextrose agar (Biotech) supplemented with chloramphenicol (antibiotics). The inoculated media used were prepared and incubated at 37 ⁰C for 24 hours for nutrient agar and eosin methylene

blue agar and 28 ⁰C for 72 hours. The numbers of viable microorganisms were counted, calculated and expressed as colonies forming units per gram (cfu/g) [7, 8]. 

Table 1 shows the proximate analysis of the weaning food produced from yellow corn, date fruits and tigernut. The approximate contents were; moisture (30.04%), ash (1.08%), fat (2.00%), fibre (0.68%), protein (5.02%) and carbohydrate (61.18%).

Table 1: Proximate Analysis of the produced weaning food

Table 2 shows the mineral contents of weaning food produced from yellow corn, date fruits and tigernut. The mineral contents were; zinc (0.91 mg/100g), magnesium (80.00 mg/100g), iron (3.82 mg/100g), calcium (52.04 mg/100g) and potassium 198.20 mg/100g). 

                Table 2: Mineral contents of the produced weaning food

                                                Key:        mg/100g = Milligram per 100 gram

Table 3 shows the vitamin contents of the weaning food produced from yellow corn, date fruits and tigernut corn. The vitamin contents were; vitamin B2 (1.48 μg/100g), vitamin B3 (6.14 μg/100g) and vitamin C (0.66 μg/100g).

Table 3: Vitamin contents of the produced weaning food

                                    Key:        μg/100g = Microgram per 100 gram

Table 4 shows the microbial load of the weaning food produced from yellow corn, date fruits and tigernut. Total viable bacterial count was 1.8 x 10⁴ cfu/g, there was no coliform count while total fungal count recorded was 8.0 x 10³cfu/g.

Table 4: Microbial load of the produced weaning food

Table 5 shows the cultural morphology and microscopic characteristics of fungal isolates from the weaning food. They were; Saccharomyces, Kluyveromyces, Mucor and Penicillium species.

Table 5: Cultural morphology and microscopic characteristics of the fungal isolates from the produced weaning food

Table 6 shows the cultural morphology and biochemical characteristics of the bacterial isolates from the produced weaning food. A total of five (5) bacteria were isolated. They include; Leuconostoc, Proteus, Bacillus, Lactobacillus and Corynebacterium species.

Table 6: Cultural morphology and biochemical characteristics of the bacterial isolates from the produced weaning food

Key:     -= Negative           += Positive            S = color of slope      B = color of butt       G= Gas production     H₂S= Hydrogen sulphide production (blackening)

R= Reddish coloration (alkaline production)  Y= Yellow coloration (Acidic production)   SFT= Sugar fermentation test.

Cereal-based diets have been found to be of lower nutritional value than animal-based ones and this forms the primary basis for most of the traditional weaning foods in West Africa [9]. Considering the above challenges faced in weaning foods, this study was carried out to determine the effect of fortification of yellow corn (used in the production of weaning food) with tigernut and date fruits on the proximate, mineral, vitamin and microbiological quality.

Proximate Content:

The carbohydrate content recorded with the weaning food was a little bit lower compared to the ones reported with weaning foods made from only maize, sorghum and millet. (Ikram, U. et al., 2010) [10] observed that carbohydrates are the major chemical components of the maize grains as they reported a range of 69.66-74.549 %.The formulated blend meets the daily nutritional requirements of growing infants. This agrees with the nutritional composition and specification for home-prepared and commercially-processed food blends as laid down by (Protein Advisory Group of the United Nations System (PAG) 2009) [11] and recommended by FDA, FAO, WHO and UNICEF (Reports 1997-2012; 2007; 2000-2016) [12]. It is also able to supply the nutritional and energy requirement of a growing child and also confer health benefits on them as stated in the FDA report (2000-2016) while meeting the daily nutrient composition of the recommended standard for weaning when compared with commercially available ones.

The moisture content recorded with this pap is very low compared to that reported by (Ponka, R. et al., 2015) [13] with pap made from five different maize samples which were within 82.10% to 86.85%. High moisture content during storage encourages the growth of certain harmful yeast, molds and bacteria [14]. Moisture content also affects the physical, chemical aspects of food which relates with the freshness and stability for the storage of the food for a long period of time and the moisture content determine the actual quality of the food before consumption and to the subsequent processing in the food sector by the food producers [15].The ash content recorded in this study was 1.08%. This was higher than that reported by (Ukegbu, P. O., & Anyika, J. U. 2012) [16] but lower than that reported by (Ponka, R. et al., 2015) [13]. The recommended dietary allowance (RDA) for ash in foods is ≤5.0 mg/100 g (Food and Agricultural Organization and World Health Organization. 1998) [3].

The protein content recorded in this study (5.02%) is higher than that recorded with pap made from only maize. In a study by (Ponka, R. et al., 2015) [16] on nutritional composition of five varieties of pap commonly consumed in Maroua, Far-North Cameroon, the protein contents of the paps ranged from 1.28% to 2.27%.  It was also higher compared to that reported by (Makanju, D. A. & Awogbanja, S. 2012) [18] which was 4.48% with pap produced from sorghum sold in Nasarawa State, Nigeria. However, (Anigo, K. M. et al., 2010) [20] reported higher protein contents (6.76% to 7.88%) with paps produced with maize and millet sold in North-western Nigeria. The recommended dietary allowance (RDA) for crude protein in foods is ≥16.0 mg/100g (Food and Agricultural Organization and World Health Organization. 1998) [3].

(Ponka, R. et al., 2015; Ponka, R. et al., 2006) [13, 21] reported that addition of raw cow’s milk and roasted peanut pastes increased the protein contents of pap. The addition of date fruits and tigernut during the production of the weaning food could have contributed to the increase of the protein content compared to that of ordinary pap made from maize. Although the protein content recorded in this weaning food is below the recommended protein content as specified by (Food and Agricultural Organization and World Health Organization. 1994) [22] which should be between 14.52 to 37.0g/100g.

The amount of fat recorded was 2.00 % which is lower than that reported by (Ponka, R. et al., 2015) [13].

High dietary fiber content has been reported to impair protein and mineral digestion and absorption in human subjects [22]. Fiber content of the weaning food was 0.68% which is below the recommended dietary allowance (RDA) for crude fiber in foods for infants (6–12 months) is 4.0 mg/100 g (Food and Agricultural Organization and World Health Organization. 1998) [3].

Mineral Contents of Weaning Food:

Magnesium is needed for the body to remain healthy. It also helps in many processes in the body, including regulating muscle and nerve function, blood sugar levels, and blood pressure and making protein, bone and DNA [19]. The magnesium content of the weaning food produced in this study was 80.00 mg/100g was higher than the magnesium content recorded by (Solomon, M. et al., 2000) [23] (23.7 mg/100g) but lower than that reported by (Anigo, K. M. et al., 2010) [20] (92.00 mg/100g) with pap consumed within Jos, Plateau State and North-western Nigeria respectively. The recommended dietary allowance (RDA) of magnesium for infants’ food is 350 mg/100g [24] and the produced weaning food had magnesium content below the recommended. 

In this study, the calcium content recorded with the weaning food produced was 52.04 mg/100g which is higher than the calcium content reported by (Ponka, R. et al., 2015) [13] with pap sold at Cameroon (30.25 mg/100g) and that of (Ukegbu, P. O., & Anyika, J. U. 2012) [16] with pap made from maize sold at Imo State. Calcium is an essential element in infants and young children for building bones and teeth, functioning of muscles and nerves, blood clotting and for immune defense [23]. 

According to (Food and Agricultural Organization and World Health Organization. 1998) [3] as reported by (Oyarekua, M. A. 2011) [24], the recommended dietary allowance (RDA) of calcium in infants’ food is 295 mg/100g and the produced weaning food had calcium content below the recommended standard. The iron content recorded was 3.82 mg/100g. This is higher than that recorded by (Henry-Unaeze, H. N. 2011) [2] with pap (2.49 mg/100g) sold at Umuahia, Abia State. 

The recommended dietary allowance (RDA) for iron in infants’ food is 10.0 mg/100g [3, 24]. The iron content of the weaning food is below the recommended standard. Iron deficiency can lead to anemic conditions in children [26].

The zinc content recorded in this study (0.91 mg/100g) was comparable with that reported by (Ponka, R. et al., 2015) [13] with five pap consumed in Cameroon. The recommended dietary allowance (RDA) for zinc in infants’ food is 3.0 mg/100g [3]. The potassium content of the weaning food was 198.20 mg/100g which was closely related with that reported by (Ponka, R. et al., 2015) [13] (198.20-322.22 mg/100g) with pap made from five varieties of maize but higher compared to that of (Solomon, M. et al., 2000)[23] who reported potassium content of pap sold at Jos, Plateau State, Nigeria to be 57.36 mg/100g. However, the potassium content was below the recommended dietary allowance of potassium for infants below 1 year which is 500 mg/100g. Low potassium intake has been associated with a lot of non-communicable diseases such as chronic kidney stone formation, and low bone-mineral density in children [27].

Vitamin Contents of the Weaning Food:

According to (Richardson, D. P. 1997) [28], the recommended dietary allowance (RDA) of vitamin B₂ is1.3 mg/100g and 16 mg/100g for vitamin B₃. Vitamin B₂ (riboflavin) is a part of the co-enzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), needed for oxidation/reduction reactions, including those involved in energy production. The vitamin B₂ content recorded with the weaning food was within the recommended dietary allowance. 

Vitamin B₃ is a part of the co-enzyme, nicotinamide adenine dinucleotide (NAD) or its phosphate form, nicotinamide adenine dinucleotide phosphoric acid (NADP). The vitamin B₃ and C content recorded in this study was below the recommended dietary allowance for vitamin B₃. 

Microbial Load:

The microbial count obtained in this study falls within the recommended safe limit of microbial guidelines for ready-to-eat foods adopted by the international commission of microbiological specification of food,which states that the microbial safe limit for ready-to-eat food should fall between the range of 10² -10⁵Cfu/ml, this also in agreement with other works by (Olayiwola, J. O. et al., 2017; Bello, O. O. et al., 2018).

A total of five (5) bacteria were isolated. They include; Leuconostoc, Proteus, Bacillus, Lactobacillus and Corynebacterium species. This suggests that most of the microbes that participate in the fermentation of maize for pap (weaning food)production are mainly bacteria, despite the fact that some yeast also participate actively in the fermentation process . The bacterial isolates were majorly lactic acid bacteria (LAB) and their presence could be connected to the acidic nature of the medium.

(Ogodo, A. C. et al., 2015) [6] reported the isolation of Lactobacillus species, Salmonella species, Leuconostoc species, Citrobacter species, Micrococcus species and Klebsiella species from laboratory prepared and

commercially prepared akamu sold within Uturu and Okigwe. (Ogwaro, B. A. et al., 2002) reported that maize porridge samples prepared for infants in Ghana were contaminated with pathogenic bacteria including Aeromonas, Bacillus cereus, Salmonella, Staphylococcus aureus and Vibrio cholerae. Similarly, (Ezendianefo, J. N., & Dimejesi, S. A. 2014) reported the isolation of Escherichia species, Staphylococcus species, Klebsiella species, Streptococcus species, Pseudomonas species, Mucor species, Aspergillus species and Fusarium species from akamu sold in Nnewi markets, Anambra State, Nigeria.

The sources of these bacteria could be from water used in fermenting the grains and the grinding machine used in grinding the grains. 

Fungi species such as Penicillium species are occasional causes of infection in humans and the resulting disease is known generically as penicilliosis . The presence of this fungus could be from grinding machines, raw materials such as; tigernut, date fruits and yellow corn used in the production of the local weaning food used in this study. (Ike, C. C. 2017)  reported the isolation of Aspergillus species, Penicillium species, Rhizopus species and Mucor species from tigernut sold at Aba Metropolis, Abia State. (Onyeze, R. et al., 2013) in their study on isolation and characterization of fungi associated with the spoilage of maize (Zea mays). Mucor, Aspergillus, Rhizopus, Penicillium and Fusarium species were associated with the spoilage of the maize.

This study showed that weaning food could be fortified with tigernut and date fruits. The results of this study have shown that fortification of weaning food (pap) with tigernut and date fruits increased the proximate, mineral and vitamin contents and microbiological quality of the weaning food. However, personal grinding machines could give a better microbiological quality weaning food since the commercial machines may contain some microorganisms capable of contaminating the finished product. Furthermore, sources of the raw materials used in the production of weaning food should be free from spoilage microorganisms and properly washed in order to avoid microbial contamination.

 No funding sources.

None declared.

The study was approved by the Institutional Ethics Committee of Federal polytechnic Nekede Owerri Imo State.

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