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

DISCUSSION:

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 (Adeyemo, S. M., & Onilude, A. A. 2018). 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 theproximate, 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) 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) and recommended by FDA, FAO, WHO and UNICEF (Reports 1997-2012; 2007; 2000-2016). 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) 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, moulds and bacteria (Dowswell, C. R. et al., 2019). 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 (Suzanne, N. S. 2010).The ash content recorded in this study was 1.08%. This was higher than that reported by (Ukegbu, P. O., & Anyika, J. U. 2012) but lower with that reported by (Ponka, R. et al., 2015). The recommended dietary allowance (RDA) for ash in foods is ≤5.0 mg/100 g (Food and Agricultural Organization and World Health Organization. 1998).

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) 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) which was 4.48% with pap produced from sorghum sold in Nasarawa State, Nigeria. However, (Anigo, K. M. et al., 2010) 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).

(Ponka, R. et al., 2015; Ponka, R. et al., 2006) 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 contents recorded in this weaning food is below the recommended protein content as specified by (Food and Agricultural Organization and World Health Organization. 1994) which should be between 14.52 to 37.0g/100g.

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

High dietary fibre content has been reported to impair protein and mineral digestion and absorption in human subjects (Satter, M. A. et al., 2013). Fibre 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).

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 (Hatanaka, M. & Ware, M. 2020). 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) (23.7 mg/100g) but lower than that reported by (Anigo, K. M. et al., 2010) (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 (Oyarekua, M. A. 2011) 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) with pap sold at Cameroon (30.25 mg/100g) and that of (Ukegbu, P. O., & Anyika, J. U. 2012) 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 (Satter, M. A. et al., 2013).

According to (Food and Agricultural Organization and World Health Organization. 1998) as reported by (Oyarekua, M. A. 2011), 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) 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 (Food and Agricultural Organization and World Health Organization. 1998; Adeyeye, E. I., & Faleye, F. J. 2004). The iron content of the weaning food is below the recommended standard. Iron deficiency can lead to anaemic conditions in children (Dickinson, J. R. & Schweizer, M. 2004).

The zinc content recorded in this study (0.91 mg/100g) was comparable with that reported by (Ponka, R. et al., 2015) with five pap consumed in Cameroon. The recommended dietary allowance (RDA) for zinc in infants’ food is 3.0 mg/100g (Food and Agricultural Organization and World Health Organization. 1998). 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) (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) 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 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 (World Health Organization. 2012).

Vitamin Contents of the Weaning Food:

According to (Richardson, D. P. 1997), 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 fall within the recommended safe limit if microbial guidelines for ready-to-eat foods adopted by the international commission of microbiological specification of food (International Commission on Microbiological Specification of Microorganisms in Food. 2002) 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 (Izah, S. C. et al., 2016). 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) 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 speciesand 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 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 (Hart, J. et al., 2012). The presence of this fungus could be from grinding machine, 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.

CONCLUSION:

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 machine 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.

REFERENCES:

1. Adeyemo, S. M., & Onilude, A. A. (2018). Weaning food fortification and improvement of fermented cereal and legume by metabolic activities of probiotics Lactobacillus plantarum. African Journal of Food Science, 12(10), 254-262.

2. Adeyeye, E. I., & Faleye, F. J. (2004). Mineral components important for health from animal sources. Biological Sciences-PJSIR, 47(6), 471-477.

3. Anigo, K. M., Ameh, D. A., Ibrahim, S., & Danbauchi, S. S. (2010). Nutrient composition of complementary food gruels formulated from malted cereals, soybeans and groundnut for use in North-western Nigeria. African journal of food science, 4(3), 65-72.

4. Association of Official Analytical Chemists (AOAC). (2005). Official methods of analysis of the Association of analytical chemists international, 18th ed. Gathersburg, MD USA official methods, 08-11.

5. Bello, O. O., Bello, T. K., Amoo, O. T., & Atoyebi, Y. O. (2018). Comparative evaluation of microbiological and nutritional qualities of various cereal-based paps (Ogi) in Ondo State, Nigeria. International Journal of Environment, Agriculture and Biotechnology, 3(2), 676-685.

6. Cheesbrough, M. (2010). District Laboratory Practice in Tropical Countries, Part I. Cambridge Univ. Press, Cambridge, pp.1-426.

7. Dickinson, J. R. & Schweizer, M. (2004). The metabolism and molecular physiology of Saccharomyces cerevisiae. London: CRC Press.

8. Dowswell, C. R., Paliwal, R. L., & Cantrell, R. P. (2019). Maize in the third world. International Journal of Agricultural Science, 6, 89-94.

9. Ezekiel, T., Solomon, L., Oforibika, A. G., & Daminabo, V. (2016). Nutritional, Sensory and Bacteriological Quality of Two Varieties of Locally Prepared Zobo (Hibiscus sabdariffa) Drink. World Rural Observations, 8(3), 99-104.

10. Ezendianefo, J. N., & Dimejesi, S. A. (2014). Microbial Quality of “AKAMU”(OGI) Sold in NNEWI Markets, Anambra State, Nigeria. IOSR J Pharm Bio Sci, 9(3.4), 33-35.

11. FDA/WHO/UNICEF. (1997-2012). Reports Recommended Daily Dietary Reference Intakes 1997-2012.

12. Food and Agricultural Organization. (2001). Improving nutrition through home gardening. 2001:A training package for preparing field workers in Africa. FAO, Rome, Italy.

13. Food and Agricultural Organization and World Health Organization. (1998). Carbohydrates in Human Nutrition. In: International Report of a Joint Expert Consultation. Rome: FAO/WHO.

14. Food and Agricultural Organization and World Health Organization. (1994). Codex Alimentarius Standards for Foods for Special Dietary Uses (including foods for infants and children, Vol. 4. Joint FAO/WHO Food Standards Program Rome: WHO, Codex Alimentarius Commission.

15. Hart, J., Dyer, J. R., Clark, B. M., McLellan, D. G., Perera, S., & Ferrari, P. (2012). Travel‐related disseminated P enicillium marneffei infection in a renal transplant patient. Transplant Infectious Disease, 14(4), 434-439.

16. Hatanaka, M. & Ware, M. (2020). Why do we need magnesium. Medical News Today, 9-12.

17. Henry-Unaeze, H. N. (2011). A Comparative study of micronutrients content of complementary foods used by igbo and hausa mothers in Umuahia, Abia State, Nigeria. Pakistan Journal of Nutrition. 10, 322–324.

18. Ike, C. C. (2017). Microbial evaluation of tigernut (Cyperus esculentus L.) sold in Aba metropolis, Abia State, Nigeria. International Journal of Scientific Engineering and Applied Science, 1(7), 46- 59.

19. Ikram, U., Muhammad, A., & Arifa, F. (2010). Chemical and nutritional properties of some maize (Zea mays L.) varieties grown in NWFP, Pakistan. Pakistan journal of Nutrition, 9(11), 1113-1117.

20. International Commission on Microbiological Specification of Microorganisms in Food. (2002). International Commission on Microbiological Specification of Microorganisms in Food. Microbiological Analysis Principles and specific applications. University of Toronto.

21. Izah, S. C., T KIGIGHA, L., & Okowa, I. P. (2016). Microbial quality assessment of fermented maize Ogi (a cereal product) and options for overcoming constraints in production. Biotechnological Research, 2(2), 81-93.

22. Makanju, D. A. & Awogbanja, S. (2012). Protein and mineral contents of commonly consumed complementary foods in Lafia, Nasarawa State, Nigeria. International Journal of Advanced Science and Technology, 5, 1–6.

23. Mbaeyi, I. E., & Onweluzo, J. C. (2010). Effect of sprouting and pre-gelatinization on the physicochemical properties of sorghum-pigeon pea composite blend used for the production of breakfast cereal. Agro-Science, 9(1), 8–17.

24. Ogodo, A. C., Ugbogu, O. C., & Ekeleme, U. G. (2015). Bacteriological quality of commercially prepared fermented Ogi (Akamu) sold in some parts of South Eastern Nigeria. International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering, 9(6), 638-641.

25. Ogwaro, B. A., Gibson, H., Whitehead, M., & Hill, D. J. (2002). Survival of Escherichia coli O157: H7 in traditional African yoghurt fermentation. International Journal of Food Microbiology, 79(1-2), 105-112.

26. Okafor, U. I., Omemu, A. M., Obadina, A. O., Bankole, M. O., & Adeyeye, S. A. (2018). Nutritional composition and antinutritional properties of maize ogi cofermented with pigeon pea. Food science & nutrition, 6(2), 424-439.

27. Olayiwola, J. O., Inyang, V., & Bello, M. A. (2017). Bacteriological and proximate evaluation of ginger-fortified fermented maize (ogi). American Journal of Food Technology, 12(6), 374-378.

28. Onyeze, R., Udeh, S. M., Akachi, B., & Ugwu, O. P. (2013). Isolation and characterization of fungi Associated with the Spoilage of Corn (Zea Mays). International Journal Pharma Medicine and Biological Science, 2(3), 86-91.

29. Oyarekua, M. A. (2011). Evaluation of the nutritional and microbiological status of co-fermented cereals/cowpea ‘OGI’. Agriculture and Biology Journal of North America, 2(1), 61-73.

30. Ponka, R., Bouba, A. A., Fokou, E., Beaucher, E., Piot, M., Leonil, J., & Gaucheron, F. (2015). Nutritional composition of five varieties of pap commonly consumed in Maroua (Far-North, Cameroon). Polish Journal of Food and Nutrition Sciences, 65(3), 183–190.

31. Ponka, R., Fokou, E., Fotso, M., Tchouanguep, F. M., Leke, R., Souopgui, J., & Bih, M. A. (2006). Composition of dishes consumed in Cameroon. International journal of food science & technology, 41(4), 361-365.

32. Protein Advisory Group of the United Nations System (PAG). (2009). Protein Advisory Group of the United Nations System. Nutrition Bulletin.

33. Richardson, D. P. (1997). The addition of nutrients to foods. Proceedings of the Nutrition Society, 56(3), 807-825.

34. Satter, M. A., Jabin, S. A., Abedin, N., Arzu, T., Mitra, K., Abdullah, A. M., & Paul, D. K. (2013). Development of nutritionally enriched instant weaning food and its safety aspects. African Journal of food science, 7(8), 238-245.

35. Solomon, M., Aliyu, R., & Mohammed, R. (2000). Nutrient composition of foodstuffs and dishes/foods of indigenous population of Jos Plateau, Nigeria. West African Journal of Food Nutrition, 2, 20–26.

36. Suzanne, N. S. (2010). Food analysis. Springer, Fourth Edition, 602.

37. Ukegbu, P. O., & Anyika, J. U. (2012). Chemical analysis and nutrient adequacy of maize gruel (pap) supplemented with other food sources in Ngor-Okpala LGA, Imo State, Nigeria. Journal of Biology, Agriculture and Healthcare, 2(6), 13-21.

38. Walker, A. F. (1990). The contribution of weaning foods to protein–energy malnutrition. Nutrition research reviews, 3(1), 25-47.

39. World Health Organization. (2012). Increase potassium intake to reduce blood pressure and risk of cardiovascular diseases in adults. WHO Report, Geneva, Switzerland.