Nigerian Food Journal最新文献

This paper concerns the water vapor adsorption properties of starch-albumen powder (SAP), as a new product with many potential food processing applications. The adsorption data were generated at some practical storage temperatures (27, 35 and 40 °C) and water activities, a_w (0.11–0.86) using gravimetric method. The data were fitted to some isotherm models (GAB, Peleg, DLP and BET). The values of some thermodynamic parameters based on the Clausius–Clapeyron equation were also calculated. The rheological behavior of SAP paste was also studied at 20, 30, 45 and 60 °C. SAP was found to have type II isotherm shape and is highly hygroscopic. The adsorption data were better fitted by Peleg and DLP models (r²=0.987–0.999). Monolayer moisture capacity ranged between 4.9 and 6.8 g/100 g solid. The water vapor sorption process in SAP is thermodynamically non-spontaneous and enthalpy-driven. SAP paste showed a characteristic shear-thinning behavior. Activation energy of flow (E_a) was found to be 31.63 kJ/mol.

An àmàlà making machine was designed and constructed to make àmàlà preparation an easy one and remove the fatigue usually experienced during manual preparation. The machine frame was from galivanised and stainless steel materials and it is capable of preparing àmàlà of averagely 1.074–2.68 kg by weight. It has two compartments, the heating and stirring compartments. The stirrer has six flat paddles arranged asymmetrically and powered by a 0.94 HP electric motor. The performance evaluation of the machine revealed that the output by weight is significantly different (P<0.5) indicating that weight is not equal due to different input. There was reduction in weight with decrease in temperature of the paste from 90–66 °C residence time 5–2.5 min and quantity of heat stored by the paste from 210.16–8.64 KJ as the input reduced. The density of the paste increases as the volume of water reduces (1223.83 kg/m³ at 1.8 Litre of water to 2303.33 kg/m³ at 0.6 Litre of water). Although, pastes produced at various ratio of yam flour and water are adjudged suitable by panellists in terms of colour, taste, aroma during sensory evaluation test, but 0.5 kg of flour produced overall acceptable paste with 1.8 Litre (maximum pot capacity), while 0.35 kg of flour produces overall acceptable paste with 0.6 Litre (minimum pot capacity)in term of modability, and texture.

African locust bean (Parkia biglobosa), fermented into “iru” or “dadawa” is a nutritious condiment featured frequently in the diet of people of Nigeria and other West African countries. Many consumers benefit from the nutrients, and enjoy the aroma of fermented locust bean seed in their foods. However, some dislike seeing the locust beans and would pick them out of their meals depriving themselves of the nutrients. The availability of iru as fermented, ground and shelf stable bouillon cube may increase the acceptability of this condiment. The objective was to develop a shelf stable iru bouillon with starches as binders. Fermented, dried and ground locust bean with binders were prepared in the ratio of 40:10 and 30:20 locust bean:binder and cubed. Microbial and proximate analyses of the cubes were carried out. Bacillus spp., Lactobacillus spp., and Staphylococcus spp. were isolated following bouillon cube production. Cassava starch bouillons had the highest moisture content (24.5% and 29.3%). Bouillons with corn starch had the highest amount of fat (22.0%), followed by cassava starch (19.6%), while bouillon cubes with potato binder had the highest crude protein content (33.9%). Iru without binders had the lowest moisture (11.5%) and ash (1.7%), the highest crude fat (30.0%) and the highest crude protein (46.3%) contents. Only Bacillus subtilis was isolated from all the samples after 9 months of storage, indicating that shelf stable iru bouillon cubes is possible, without chemical preservatives. Conclusively, iru bouillon cubes with binders improved the shelf life from few days to over nine months without compromising the safety of the product.

The thin layer drying characteristics of dika kernels and nuts were investigated at four drying temperatures of 50, 60, 70 and 80 °C and the data was fitted to drying models. Non-linear regression analysis was used to determine model parameters, while coefficient of determination (R²) and standard error of estimate (SEE) formed the basis for determining the model of best fit. The Modified Henderson–Pabis drying model gave the best fit for the dika kernels while the two term model was best for the dika nuts. Effective moisture diffusivity ranged from 2.84×10⁻¹⁰ m²/s to 5.06×10⁻¹¹ m²/s for the kernels and from 1.22×10⁻¹⁰ m²/s to 2.03×10⁻¹⁰ m²/s for the nuts. The activation energies of dika kernels and nuts were 16.747 kJ/mol and 37.019 kJ/mol respectively.

Mixed fruit leathers were produced from purees of apple, banana and pineapple. The proximate composition, physico-chemical and organoleptic properties of the samples were evaluated. Furthermore, the samples were used as ingredients in producing cakes and sensory evaluation were carried out on them. The physico-chemical parameters studied were total soluble solids (TSS), total titratable acidity (TTA), fixed acidity (FA), volatile acidity (VA), pH, and vitamin C. There were significant differences (p<0.05) in the TSS of the samples. However, sample 819 (40% banana: 40% pineapple: 20%: 40% apple) had the highest TSS (20.07 g) and TTA (0.42 g/l) and significantly differed from other samples (p<0.05). Sample 443 (20% banana: 40% pineapple: 40% apple) had the highest fixed acidity (5.6 g/l), volatile acidity (26.00 g/l) and vitamin C (22.33 mg/100 g) and differed significantly (p<0.05) from other samples. The proximate compositions studied showed that sample 819 (40% banana: 40% pineapple: 20%: 40% apple) was significantly higher in ash (1.20%), protein (0.71%) and carbohydrates (84.77%) than other samples, while sample 443 (20% banana: 40% pineapple: 40% apple) was however, higher than other samples in moisture content (4.14%) and fat content (2.32%). The highest fiber content (12.47%) was observed in sample 314 (60% banana: 20% pineapple: 20% apple) while the least was in sample 819 (40% banana: 40% pineapple: 20%: 40% apple). There were no significant differences (p>0.05) among the mixed fruit leather and cakes samples. The general acceptability of the cake samples were the as that of the control (commercial fruit cake), they were moderately liked by the panelists.

Edible mushrooms are used in the preparation of several delicacies in many parts of Nigeria; however, little information is available on the nutritional qualities of oyster mushroom (Pleurotus sajor-caju) cultivated on gmelina wood waste. This study ascertains the nutritional and anti-nutritional amino acid and fatty acid composition of commercially grown oyster mushroom (P. sajor-caju) on gmelina wood waste in Forestry Research Institute of Nigeria. The sample was obtained and analyzed for fatty acid profile and amino acid profile on dry weight basis using standard methods. The chemical score of the essential amino acid of the sample, which ranged from 55.94% (methionine) to 150.31% (isoleucine), was comparable to standard dietary reference intake requirement. Fatty acid profile showed the presence of polyunsaturated (linolenic 29.54%, linoleic 11.6% and arachidonic 0.22%), monounsaturated (oleic 41.71%, palmitioleic 0.22% and erucic 7.09%) and some saturated (caprylic 0.92%, myristic 0.18%, palmitic 5.34%, margaric 0.21%, stearic 2.38%, arachidic 012%, behenic 0.25% and lignoceric 0.16%) fatty acid. This study showed that oyster mushroom grown on gmelina wood waste has potential for use as acceptable human food.

This work investigated the effect of yam flour substitution on characteristics of wheat bread and also determined the functional properties of the experimental flour samples. Flours were obtained from three varieties of yam (Dioscorea rotundata, Dioscorea alata and Dioscorea bulbifera) and blended with wheat flour at 25, 50 and 75 percent levels of substitution for bread production. Wheat flour (WF) and each of the yam flours were used as the positive and negative controls respectively. The functional properties (bulk density, water/oil absorption capacities, emulsion activity) of the flour samples were determined while the proximate, physical and sensory characteristics of loaves were also determined. The functional properties of the flour samples ranged from 0.42 g/ml to 0.67 g/ml packed bulk density; 0.39 g/ml to 0.47 g/ml loose bulk density; 0.88 ml/g to 2.10 ml/g oil absorption capacity; 1.50 ml/g to 3.90 ml/g water absorption capacity and 43.75% to 49.37% emulsion activity. The proximate composition of the bread samples ranged from 26.82% to 38.90% moisture, 4.23% to 5.10% fat, 6.10% to 9.25% protein, 1.90% to 2.45% ash, 0.12% to 0.64% crude fiber and 46.43% to 56.71% carbohydrate. The volume, weight and specific volume of loaves varied from 200 ml to 400 ml, 142.6 g to 170.2 g and 1.18 ml/g to 2.81 ml/g respectively. The crack formation of bread samples showed that there were no cracks on wheat bread (WF) and 25% yam flour substituted breads while 100 percent yam flour breads had large cracks. The sensory properties of the 25% yam flour substituted breads were statistically (p>0.05) the same with the 100% wheat bread but differed from all the other bread samples. The mean score of the sensory attributes decreased as yam flour increased in the formulation. Sensory Evaluation of the bread samples showed that substitution level of 25% yam flour produced bread that was acceptable to the consumers whereas up to 50% and above were not acceptable. It is therefore recommended that substitution level of not more than 25% yam flour be used for yam/wheat composite bread production.