ABSTRACT
Plantains are widely used as a source of nutrition all over the world. They can be used to promote the diversification of locally made agricultural products to improve the diets of consumers. The aim of this study was to ascertain the microbiological and physicochemical quality of gruel prepared from Musa paradisiaca (plantain).
Three brands of commercial custard and samples of pap were purchased from three markets; Uselu, Oluku, and Oba in Benin-City, and transported to the laboratory. Freshly harvested plantains were purchased from Oba market in Benin, Edo state, washed, dried and processed using separate techniques to produce plantain gruel A and plantain gruel B respectively. Isolation of fungi, heterotrophic bacteria, coliform, and staphylococci microorganisms from plantain gruel (A), plantain gruel (B), commercial custard (C) and pap (D) were carried out using Potato dextrose agar, Nutrient agar, MacConkey agar and Mannitol salt agar respectively. pH was determined using the Hanna microprocessor pH meter. Titratable acidity was determined by titrating them against standard 0.1N sodium hydroxide solution. Proximate composition of the food samples were determined using standard methods of AOAC. Mineral analysis was carried out using the atomic absorption spectroscopy, flame photometric and spectrophotometric methods. Fish meal had the highest concentration of magnesium and was used in the fortification of plantain gruel A and B. Sensory analysis was carried on the food samples using the 9-point hedonic scale.
Pap had the highest fungal count (13.7 ± 2.11x103cfu/g), heterotrophic bacterial count (18.1 ± 2.42x103cfu/g), coliform count (8.00 ± 12.16x103cfu/g) and staphylococcal count (17.00 ± 1.11x103cfu/g). Saccharomyces (33.36%), Fusarium (9.09%) had the highest and lowest frequency of occurrence respectively. Yeast (Saccharomyces)was isolated from all samples; pathogenic fungi were isolated from sample C and D. Lowest and highest frequency of bacterial occurrence belonged to the genera Leuconostoc (4.2%) andShigella (20.8%) respectively. Sample B had the highest pH of 6.01 ± 0.08, sample D had the highest titratable acidity of 1.54 ± 0.04 %. Sample D had the highest mean for moisture (13.5± 1.36%), ash (5.27± 1.63%), fats (2.57± 0.62%); Sample C had the highest mean for carbohydrate (84.50± 2.02%); sample B had the highest mean for crude fiber (2.40± 0.70%) and sample A had the highest mean for crude protein (3.35± 0.57%). Sample A had the highest mean for phosphorus (0.53± 0.03%) and iron (39.10± 2.42%); Sample B had the highest mean for calcium (1.07± 0.06%), potassium (65.50± 1.51%) and magnesium (0.51± 0.02%); sample C had the highest mean for zinc (18.00± 2.41%) and manganese (4.99± 0.17%) while sample D had the highest mean for sodium (7.80± 2.41%). Plantain gruel was fortified with 48g of fish meal to increase its magnesium concentration from an initial concentration of 0.48 ± 0.06 mg/100g (A); 0.51 ± 0.02mg/100g (B) to a final concentration of 98mg/100g. Sensory analysis for appearance ranged from 5.55 ± 2.09 (A) – 7.60 ± 0.99 (C); mean for aroma ranged from 1.93 ± 0.70 (B) – 7.27 ± 1.03 (C); mean for taste ranged from 5.33 ± 2.09 (A) – 6.40 ± 1.35 (C); mean for texture ranged from 5.50 ± 1.78 (B) – 7.73 ± 0.96 (C) and general acceptance ranged from 4.60 ± 2.13 (C) – 6.73 ± 1.83 (A).
