The consumption of ready-to-eat food products is on the increase globally as people are becoming busier by the hour, with little or no time invested in preparing foods especially breakfast an important meal of the day after an overnight fast. Foods used for breakfast especially flakes provide energy and satiate the body with little or no added property intended to improve the health of the consumer.

In recent times, there has been increase in the need to diversify agricultural food commodities to new value added products that will enhance food availability and variety. Mushroom, an edible fungi of diverse species [1], have been gaining recognition as a useful food material because of its nutritional and medicinal benefits [2]. The need to enhance mushroom usage from seasonally to all-round availability has led to its cultivation and varied application in the food and health industry.

Mushroom research is globally in the spotlight mainly because of health which is the key driver of mushroom awareness and promotion [3]. Research on mushroom usage in the food industry is dynamic with new applications unfolding by the day. Mushrooms have been reported to have nutraceutical properties and bioactive components [1,4], which is the reason behind its varied applications. Incorporation of mushroom into food products for regular consumption will avail individuals of its unique and beneficial components. 

Cultivation of Mushroom is very simple and involves low cost production technology that uses agro waste and gives steady growth with high biological efficiency and production turnover [5], hence economically and ecologically friendly to food industries. Varied species of Pleurotus grow well in flexible temperature conditions [6], hence they are ideally suited for cultivation throughout the year ensuring availability of raw materials to industries all year round. P. floridanus specie was used for this study because of its high resistance to brown blotch disease which majorly affects Pleurotus species and specie productivity [7].

The consumption of ready-to-eat food products is on the increase globally as people are becoming busier by the hour, with little or no time invested in preparing foods especially breakfast an important meal of the day after an overnight fast. Breakfast cereal is defined as any food obtained by the swelling, roasting, grinding, rolling or flaking of any cereal [8]. Eating breakfast is vital to our body and mind because after 8-12 hours without food, the brain and muscles will be short of caloric energy to function [9]. 

Foods used for breakfast especially flakes provide energy and satiate the body with little or no added property intended to improve the health of the consumers. It is a known fact that diets of most low middle income countries consist of foods that are mostly carbohydrate based. This situation therefore creates a need to use locally available inexpensive high nutrient sources to balance the nutrient profile of the staple diets in order to enhance nutritive value [8]. This study applied the use of high legume protein (soy bean), gluten free flour (maize and sorghum) and mushroom as cheaper source of nutrients to improve the quality of ready-to-eat cereal flakes. This study is significant in the improvement of the nutritional quality of ready-to-eat cereals by complementing their limiting nutrients with legumes and mushroom.

The research was carried out at University of Port Harcourt, Rivers state, Nigeria. Raw materials/ ingredients (Maize, sorghum, soybean, salt, sugar and vegetable oil) were purchased from local markets within Port Harcourt metropolis. While mushroom (Pleurotus floridanus), was purchased from mushroom unit Faculty of Agriculture University of Port Harcourt.

Preparation of Ingredients

Maize, sorghum and mushroom were washed separately with clean water to remove dirt, sun dried and milled into flour using a local hammer mill until it feels smooth to touch (200–212 microns).

Preparation of Soy Bean Flour

The Soybeans seeds were sorted and washed to remove dirt and contaminants. The seeds were then soaked in water for 8 hours then placed in a colander to drain off the water. The beans were boiled for 20 minutes to inactivate enzymes activity. The beans were then roasted at 120°C for 30 minutes in an oven. The roasted beans were then milled into flour using the dry compartment of the kitchen blender and stored in an air tight container till used.

All ingredients were then mixed in the ratio of 20:10:5:10 grams for maize, sorghum, soybean and mushroom respectively as the treatment and 20:10:5 grams for maize, sorghum and soybean respectively as the control. Keeping other ingredients (sugar, salt and water) at constant (5:5:125mL respectively) for both products, flakes were produced. Weighing of the samples was done using a sensitive digital scale graduated to the nearest 0.01grams. Liquids were measured using standard measuring cups. The vegetable oil was used to brush the surface of the aluminum foil sheet that was used to line the baking tray.

Procedure of Flake Production

• Preheat oven to 350 degrees. Line 2 baking trays with foil and grease lightly with oil

• Measure into two separate bowls ingredients for product “A” and “B” respectively and mix

• Add water to each bowl and mix thoroughly. The mixture should be thin and of a flowing consistency. Pour the mixtures into the prepared trays such that it covers the entire surface of the foil, forming a thin sheet over the foil surface

• Bake on the center rack for 10-15 minutes, keeping a close eye on it, until the dough has dried out and cracked

• Remove from oven and lower heat to 250. Allow the tray to cool, then with your hands crack the dough into small flakes. Return to oven and bake on the center rack for another 45 minutes or until pieces are toasted, crisp and golden

• Remove from oven and allow cooling. The flakes can be consumed dry as a snack or immersed in milk or any desired liquid and eaten as a cereal. Store leftovers in an air-tight container in a cool dry place

Chemical Analysis

Proximate and mineral analysis of the products was conducted using standard method of Association of Official Analytical Chemists [10]. However, carbohydrate content of both samples was assessed by direct determination using Manual Clegg Anthrone method [11].

Sensory Evaluation

The sensory evaluation for the acceptability of the product was done in the Faculty of Agriculture, University of Port Harcourt. Random sampling was used to select 2 students from each of the five Departments in the Faculty who formed the panelist/judges that assessed the product that was developed.

A five-point hedonic scale of like extremely, like, undecided, dislike and dislike extremely, was used for sensory evaluation of the product to determine its acceptability. The parameters evaluated include appearance/colour, taste, aroma, mouth feel and general acceptability of the products. The evaluation form for the product was collected at the end of each testing session from each judge.

Statistical Analysis

Data obtained from the proximate and mineral investigation of the products was analyzed using mean and standard deviation while T-test was used to compare mean difference between the two products. Significant difference was accepted at p <0.05. Data obtained from sensory evaluation of the product was analyzed using frequency and mean.

The proximate composition of the two samples is presented in Table 1. 

There are significant differences between the two samples with p <0.05. The moisture content of both products was low. The control had (11.17%) moisture which is higher than that of the Mushroom Flakes (MF) (6.20%). This implies that the Mushroom Flakes will not support microbial growth easily hence it possesses a longer shelf life, since the moisture content of a food affects its stability and overall quality [12]. The crude protein content of MF (11.73%) is higher than that of the control (9.17%). This shows that the addition of mushroom increased the protein content of the flakes. The protein content of MF is higher than that of ogi; a popular breakfast cereal in Nigeria, which has been reported to contain 10.92% crude protein [12]. The crude fat content of MF (4.40%) is slightly higher than the control (3.47%). This shows that the addition of mushroom increased the crude fat content of the flakes; however, the low crude fat content of the flakes implies that they will not easily become rancid. Crude fibre content of MF (2.04%) is higher than the control (1.64%). Fibre is important for the removal of waste from the body thereby preventing constipation and many health disorders, hence the need to consume flakes with adequate amount of liquid to help aid elimination. The ash content of the control (2.03%) is slightly higher than MF (1.92%) implying the presence of minerals in both samples. The addition of mushroom to the sample did not increase the ash content of the mushroom flakes. The carbohydrate content of both flakes are high, MF (77.57%) had higher CHO than the control (76.13%). The addition of mushroom slightly increases the carbohydrate content of the flakes. The high carbohydrate content of both products suggests that they would be able to supply the body with energy that can be sustained for a long time. However, this high values are similar to those of Pradeep et al., [13], who reported high carbohydrate values for their multigrain ready-to-eat snack mix. Generally, the addition of mushroom improved the nutrient content of the flakes.

Results for mineral composition of samples are indicated in Table 2. 

Mushroom flakes (MF) had higher mineral contents than the control. Calcium content of MF (183.50mg/100g) was significantly lower (t = 2789.53, p = 0.00) than the control (519.79mg/100g). This would probably increase with increase in quantity of mushroom added during production. Magnesium content of the control (1127.40mg/100g) was significantly higher (t = 17813.96, p = 0.00) than MF (242.27mg/100g). However, MF had higher value compared with 49.0mg/100g reported by Pradeep et al. [13]. The result for MF is however lower than the RDI for magnesium (400mg) [14]. Findings imply that the addition of mushroom inhibited the magnesium content of the flakes. The potassium content of both samples was high and exceeds the recommended daily intake (RDI) for potassium (3500mg) [15]. The addition of mushroom significantly increased (t = -63193.93, p = 0.00) the potassium content of MF (6600.67mg/100g) compared with the control (4400.33mg/100g). The manganese content of both samples meets the RDI (5mg) [15], for manganese but are not significantly different (t = 1.50, p= 0.21) from each other. However, the control had 10.25mg/100g while MF had 10.17mg/100g manganese each.

Iron content of mushroom flakes was significantly higher (t = -557.03, p = 0.00) than the control, but iron contents of both samples exceeds the RDI for iron (18mg). MF and control had 110.38mg/100g and 80.72mg/100g iron respectively. The higher iron content of MF implies that the addition of mushroom increased the iron content of the flakes. It is known that iron from plant sources (non heme) is biologically unavailable. So consumption of mushroom flakes product with vitamin C rich fluids or liquids will help enhance iron assimilation as well as reduce incidence of anemia. The zinc content of both samples was higher than the RDI (16mg) [15]. However, MF had significantly higher (t = -207.85, p = 0.00) zinc (34.47mg/100g) than the control (21.49mg/100g), implying they are rich source of zinc. Consumption of MF will enhance gonad functions [16], since most of our foods are limiting in zinc. The phosphorus contents of both control (1593mg/100g) and MF (3509mg/100g) are higher than the RDI (1000mg) [15], for phosphorus. However, the phosphorus content of MF was significantly higher than the control (t = -54574.97, p = 0.00). The result shows that the samples are rich sources of phosphorus and their consumption will greatly enhance cell functioning.

Result of the sensory evaluation of the samples is shown in Table 3.

 All samples had mean values for both the tested parameters and pooled means higher than the cut-off mean of 3.00 on a 5-point scale. This implies that all the products are acceptable with varying degrees of preference.

Sample (MF)’ is the most accepted product having a pooled mean of 4.65 when compared with the cut-off mean of 3.00. Sample (MF) had higher mean values on all parameters tested when compared with the control. This implies that it is the most preferred and capable of gaining mass acceptance on a larger production scale.

The study has shown that addition of mushroom in the production of cereals flakes, improved the nutritional quality of the flakes especially in terms of minerals. This is of importance because consumption of cereal flakes is universal and addition of mushrooms to flakes production will enhance its nutrient quality and medicinal value which can help address the issue of hidden hunger which is a global concern. The Mushroom flakes produced in this study compared favourably with other cereal produced with some similar ingredients as reported by Pradeep et al. [13], Samuel and Otegbayo [12] and Usman et al. [8], with its mineral content meeting the Recommended Dietary Intakes for most minerals. Results from sensory evaluation of the mushroom flakes indicate that it is capable of gaining wide acceptance on a larger production scale.

1. Valverde, M.E. et al. “Edible mushrooms: improving human health and promoting quality life.” International Journal of Microbiology, 2015, https://doi.org/10.1155/2015/376387.

2. Deepalakshmi, K. and Mirunalini, S. “Pleurotus ostreatus: An oyster mushroom with nutritional and medicinal properties.” Journal of Biochemistry and Technology, vol. 5, no. 2, 2014, pp. 718–726.

3. Mushrooms and Health Global Initiative (MHGI) Bulletin. “An ISMS global initiative to increase the worldwide consumption of mushrooms through the collection, evaluation and dissemination of scientifically validated information.” MHGI Bulletin, May 2015, Issue 30, http://www.isms.biz/wp-content/uploads/2015/07/MHGIBulletin_May15-Iss30.pdf.

4. Valdez-Morales, M. et al. “Effect of maize genotype, developmental stage and cooking process on the nutraceutical potential of huitlacoche (Ustilago maydis).” Food Chemistry, vol. 119, no. 2, 2010, pp. 689–697.

5. Sanchez, C. “Cultivation of Pleurotus ostreatus and other edible mushrooms.” Applied Microbiology and Biotechnology, vol. 85, 2010, pp. 1321–1337.

6. Ahmed, S.A. et al. “Biological efficiency and nutritional contents of Pleurotus florida (Mont.) singer cultivated on different agro-wastes.” Nature and Science of Sleep, vol. 7, no. 1, 2009, pp. 44–48.

7. Okorley, B.A. et al. “Resistance sources to brown blotch disease (Pseudomonas tolaasii) in a diverse collection of pleurotus mushroom strains.” Pathogens, vol. 8, 2019, p. 227. https://doi.org/10.3390/pathogens8040227.

8. Usman, G.O. et al. “Proximate composition and anti-nutrient properties of breakfast cereal made from blends of local rice, soybeans and defatted coconut flours.” Journal of Nutrition and Food Science, vol. S11, 2015, p. S11006. https://doi.org/10.4172/2155-9600.1000S11006.

9. Peñuela, C. “The importance of breakfast.” EDIS, vol. 2009, no. 9, 2009, https://journals.flvc.org/edis/article/view/118121.

10. Association of Official Analytical Chemists. Official Methods of Analysis of the Association of Analytical Chemists International. Gathersburg, MD, U.S.A., 2005.

11. Osborne, D.R. and Vooght, P. “Manual clegg anthrone method.” The Analysis of Nutrients in Foods, Academic Press, 1978, pp. 130–134.

12. Samuel, F.O. and Otegbayo, B.O. “Chemical analysis and sensory evaluation of ogi enriched with soybeans and crayfish.” Nutrition and Home Science, vol. 36, no. 4, 2006, pp. 214–217. https://www.researchgate.net/profile/Bolanle_Otegbayo/publication/249365811_Chemical_analysis_and_sensory_evaluation_of_Ogi_enriched_with_soybeans_and_crayfish/links/550c71c30cf2128741610d.

13. Pradeep, P.M. et al. “Formulation and nutritional evaluation of multigrain ready-to-eat snack mix from minor cereals.” Journal of Food Science and Technology, vol. 51, no. 12, 2014, pp. 3812–3820.

14. Yates, A. et al. “Dietary reference intakes: The new basis for recommendation for calcium and related nutrients, b vitamins and chlorine.” Journal of the American Dietetic Association, vol. 98, 1998, pp. 699–706.

15. National Research Council. Recommended Dietary Allowances. 10th ed., National Academy Press, Washington, DC, 1998, pp. 174–184.

16. Groff, J.L. and Gropper, S.S. Advanced Nutrition and Human Metabolism. 3rd ed., Wadsworth Thomson Learning, USA, 2000, p. 584.