Production, Nutritional and Microbiological Evaluation of Mahewu a South African Traditional Fermented Porridge

Abstract

Production, Nutritional and Microbiological Evaluation of Mahewu a South African Traditional Fermented Porridge Aim: To investigate the microorganisms associated with laboratory production of Mahewu and to evaluate its nutritional property. Study Design: Completely randomized design (CRD) was used with fermentation time considered as treatments and levels of microorganisms as factors. Place and Duration of Study: All works were carried out in the Department of Microbiology, Faculty of Science, University of Ibadan, from May 2013 – January 2015. Methodology: The Microbiological evaluation was carried out using the culture dependent method. Physicochemical properties were studied using a pH meter and titratable acidity was determined using titrimetic method. Enzymatic assessment was carried out using Dinitrosalicyclic acid method (DNSA) with the aid of a spectrophotometer. Nutritional analysis was determined using the Association of Analytical Chemist (AOAC, 2005) method and atomic absorption spectrophotometer, while sensory properties were carried by panel evaluation. Results: The study revealed that the microorganisms predominantly associated with the production of mahewu were yeast and lactic acid bacteria. The physicochemical study showed that an inverse relationship occurred between the pH and titratable acidity. The amylolytic activity was significantly higher (P<0.05) at the beginning of the fermentation process but declined towards the end. The moisture content increased significantly from 14.80% in the raw maize to 85.50% in mahewu while the protein, fat, ash, fibre and carbohydrate contents decreased significantly (P<0.05) from 11.00%, 4.83%, 1.55%, 1.10% and 66.72% respectively in raw maize to 9.21%, 2.02%, 1.03%, 0.83%, and 63.01% respectively in the produced mahewu sample. Similarly, the mineral contents analysis showed that sodium, potassium, calcium, iron, zinc and manganese contents decreased significantly (P<0.05) from 0.058±0.01 mg/kg, 0.109±0.03 mg/kg, 0.062±0.02 mg/kg, 2.555±0.01 mg/kg, 0.104±0.03 mg/kg and 0.700±0.08mg/kg respectively in raw maize to 0.051± 0.00 mg/kg, 0.82±0.01 mg/kg, 0.55±0.01 mg/kg, 1.963±0.06 mg/kg, 0.911±0.09 mg/kg and 0.528±0.01 mg/kg in the produced mahewu sample. The product was highly accepted by the consumers as indicated by the result of sensory evaluation. Conclusion: The produced Mahewu was highly nutritious with good consumer’s acceptability and the microorganism involved could serve as potential starter cultures.