Advanced Materials Research Vols. 18-19

Abstract: The effects of detergent on the microbiological changes of cassava for fufu production were investigated for a period of 72hr. Microbiological analyses of the fermenting cassava samples using standard methods were carried out. Six microbial species: Lactobacillus plantarum, Citrobacter freundii, Corynebacterium manihot, Lactobacillus cellobioscus, Pseudomonas alcaligens, and Leuconostoc mesenteriods were identified for the control. The same organisms were identified for the low detergent concentrations (1g/L, 2g/L) except Corynebacterium manihot, Leuconostoc mesenteriods, which were completely destroyed. High detergent concentrations (4g/L, 8g/L) inhibited the growth and subsequently killed all the organisms living very few Citrobacter freundii behind. At low detergent concentrations the cassava ferment within 48hr without objectionable odour. However, at high detergent concentrations there was no fermentation even after 72hr. The control samples fermented after 72hr with undesirable odour.

Abstract: Comparative evaluation of kinematics and ergonomic studies of traditional and motorized kneading methods for extraction of groundnut oil was conducted. Moisture and oil contents of Samnut-10 used was found to be 7.3% and 43.6 % respectively. Subject’s energy capacity per day was 0.548 kcal / day. The average throughput capacities of kneading 5.5kg groundnut paste for traditional and motorized kneading methods were 0.56 kg / minute and 0.87 kg / minute respectively. Average weights of oil obtained and extraction efficiency for the said quantity for the traditional and motorized kneader were: (1.6kg, 1.7 kg) and (82.4 %, 91.33 %) respectively. At the oil forming stage, the drudgery of kneading in traditional method was eliminated by the motorized kneader via the fingers attached to the shaft in the hopper.

Abstract: Two varieties of cowpea namely indigenous brown (Variety A) and RMP- 12 (Sampea -10) white (Variety B) were collected and their Physicomechanical properties were determined. The results of moisture content, sizes and mass of pods and seeds were { (6.5 % & 6.8%), (5.5 % & 6.0 %)}, { (150 mm & 130 mm), (9 mm & 10 mm)} and {(1.8g & 2.0 g ),( 0.9g & 0.8 g)} respectively. Other results found were particle density, angle of repose, coefficient of friction , hardness and shape/ sphericity of seeds and pods were {(280g & 376 g), (287 g & 275g ) }; {(39o & 36o ), (29.6o & 30 .9o)} {(0.58 & o.63), (0.42 & 0.41)}; {(5N & 5N), (9N & 8.5 N) and {66 % & 69 %) , (79 % & 75 %)} respectively. The F- 0 values obtained for the varietal differences were found less than those in the F- Table at 5% level of confidence, which signified the non existence of significant differences between the varieties. The physicomechanical properties were used for the design of a motorized cowpea thresher.

Abstract: Freshly harvested cassava(Manihot esculenta) roots were processed into selected products( gari, ‘pupuru’, ‘Lafun’, chips and starch) using unit operations such as peeling, washing, cutting, grating, dewatering(fermentation), smoking, granulated roasting(garifying), milling, packaging). The effects of processing on the yield and phsicochemical properties of the products were investigated. The results showed that peeling accounted for about 22% loss, grating and dewatering operations resulted in over 25% loss. Peeling, dewatering and various drying operations resulted in the detoxification of the products, also moisture contents and pH of the products were reduced. The final yields stood at 22.60%, 31.80%, 40.50%,50.60% and 57.20% for starch, gari, ‘pupuru’, ‘lafun’ and chips respectively. The protein contents of the products ranged between 1.60% and 2.80%. The moisture contents ranged between 8.50% and 10.60% for all the products. The processing operations affected the yield and the physico- chemical properties of the cassava products. Cassava processors should take precautionary measures to reduce wastage thereby increasing the yield and returns for their labour.

Abstract: A moisture-measuring device for the determination of percentage moisture content of cassava particulate on dry basis during drying process was developed used to investigate the effect of pressure on the resistance of the cassava particulate sample. A thermo-gravimetric sample analysis was used for the calibration of the moisture measuring device. The device had four electrode cups, two of which were used as dummies to give a ½ Wheatstone bridge circuit used to measure the resistance. The resistance of the cassava samples increases with decrease in the %moisture content and decreases with increase in pressure.

Abstract: The force required to shell melon seed by static loading techniques was investigated with an experimental rig machine. Melon seeds were categorized based on their moisture content into 4 sub-samples by soaking. Ten seeds from each sample were randomly selected and loaded in three different loading orientations x, y and z. The mean force required to crack the seeds was determined. Results showed variations in force, while analysis of variance showed significant difference in the loading orientation and no significant difference in the interaction of moisture content, at 95% level of confidence.

Abstract: The effects of material geometry on some rolling parameters have been studied. In a recent work, geometrical variation was introduced into the Reverse Sandwich Rolling Model (RSM) for AISI316 Stainless Steel (HCSS316) to study the effect of ingot geometry on temperature distribution during hot rolling. Validation of the model was however limited to hot rolling simulation at low reductions. In this work, the RSM, simulated in FORTRAN, is validated with hot rolling experimental data for higher reductions. Results obtained revealed a similar pattern of symmetrical temperature distribution from the rolling surfaces, to the midthickness of the material as earlier observed at low reductions.