The effect of moisture on physical properties of sorghum and millet

Knowledge of how the physical properties of grain vary with changes in moisture content is one of the prerequisites for the design and development of efficient processing and handling machines for the grains. Physical properties of two varieties of sorghum (Dionje and Jumbo) and one variety of pearl millet (IM) were investigated at different moisture levels within the moisture range 12 to 25% dry basis. Grain samples with different moisture levels were obtained by adding calculated amounts of distilled water to the grain, mix thoroughly and seal the samples in polythene bags and keep them in refrigerator at 5°C for fourteen days to allow moisture to distribute uniformly within the sample. The results showed that within this moisture range, all the physical properties studied varied linearly with moisture content. Linear dimensions (length, width and thickness), geometrical mean diameter, sphericity, surface area, volume, kernel density and porosity increased with increase in moisture content of the grain. On the other hand, bulk density decreased with increase in moisture content of the grain. Journal of Agriculture, Science and Technology Vol. 7(1) 2005: 30-4

Particle Size Distribution in Milled Sorghum Grains of Different Corneousness

The particle size distribution of milled samples of three varieties of sorghum [Sorghum bicolor (L) Moench] coded V3, V6 and V8 was determined by sieve analysis. The moisture content of the grains ranged between 9.83 and 10.60%, wet weight basis. The milling was carried out on whole grains using a laboratory pin mill while the sieving was carried out using six metric standard sieves of 810, 572, 500, 400, 315 and 210 µm apertures. The particle size distribution was displayed graphically by plotting the size frequency bar charts. From the investigation it was concluded that the particle size (d) distribution of milled sorghum grains is bimodal at the 210-315 µm and 500 572 µm size ranges; that the less corneous the grain the less pronounced is the 500 572 µm size range peak and that the more corneous the grain the more resistant it is to comminution even at increased milling intensity. There was a significant difference (

The effect of moisture on physical properties of sorghum and millet

Knowledge of how the physical properties of grain vary with changes in moisture content is one of the prerequisites for the design and development of efficient processing and handling machines for the grains. Physical properties of two varieties of sorghum (Dionje and Jumbo) and one variety of pearl millet (IM) were investigated at different moisture levels within the moisture range 12 to 25% dry basis. Grain samples with different moisture levels were obtained by adding calculated amounts of distilled water to the grain. Mixing was done thoroughly, the samples sealed in polythene bags and kept in refrigerator at 5oC for fourteen days to allow moisture to get distributed uniformly within each. The results showed that within this moisture range, all the physical properties studied varied linearly with moisture content. Linear dimensions (length, width and thickness), geometrical mean diameter, sphericity, surface area, volume, kernel density and porosity increased with increase in moisture content of the grain. On the other hand, bulk density decreased with increase in moisture content of the grain. Journal of Agriculture, Science and Technology Vol. 8 (1) 2006: pp. 43-5

The quality of water in small community supplies of Kingolwira village, Morogoro, Tanzania

Water quality is an important aspect in human health, as the majority of infectious diseases that cause morbidity and mortality in population are water related. The present study was undertaken to assess the quality of water in Kingolwira, Morogoro Rural District, Tanzania. Water was collected from different sites in the village and analysed for a period of six months. Physical, chemical and microbiological qualities of water were examined. The pH of the water ranged from 7.02 to 7.20 and the water temperature ranged from 25.7°C to 27.0°C. The total dissolved solids of the water samples ranged from 110 to 510 ppm. The water contained considerable levels of lead and copper ranging from 0.034 to 0.090 ppm and 0.022 to 0.030 ppm, respectively. Total water hardness ranged from 19.60 to 228.10 ppm as calcium carbonate. The total viable counts and faecal coliform counts ranged from 2.75x103 to 5.4 x 103 c.f.u/ml and 0.93 x102 to 2.1x102 counts/100ml, respectively. Overall, water supplies in the village were judged as of poor quality. Water is usually used for domestic purposes including cooking, drinking, washing and preparation of infant foods without any treatment. In conclusion therefore, water in Kingolwira village is of poor quality and needs to be treated before consumption. Theres is also a need for the rural population to be educated on hazards of using untreated water. In general, sanitary facilities in rural areas in Tanzania need to be improved in order to avoid health hazards

Evaluation of Bacteriological Stability of Minced Canned Meat Stored Under Simulated Tropical and Subtropical Conditions

Thermal inactivation of spoilage microorganisms is one of the widely used commercial food preservation techniques. However, its application may be too costly in terms of energy expenditure or inappropriate in terms of product quality. In this study, an attempt was made to produce tropical storage stable canned meat using remarkably milder heating effects than those commonly used by food processors. Canned beef in its own juice was used as a model product and Bacillus stearothermophilus (Merck Art No. 11499), Clostridium sporogenes (ATCC 10000) and Clostridium thermosaccharolyticum (ATCC 7956) as reference strains. The raw minced meat used for the formulation of the product was contaminated with spores of the aforesaid strains at 104-106 spores/g prior to the heat treatment. The heating effects (Fc – values) were measured throughout the experiment at the geometrical middle point (GMP) of the can. The canned meat was thereafter stored up to six months under simulated tropical and subtropical temperatures of 55oC and 25oC respectively, followed by bacteriological investigations. Results showed that C. sporogenes is of no significance in the production of tropical storage stable canned meat products. This strain was eliminated by Fc = 3.0 even at a very high contamination level of 106 spores/g. At the same level of contamination, heating values of Fc = 13.0 and 16.0 were needed to eliminate spores of C. thermosaccharolyticum and B. stearothermophilus, respectively. At a reduced contamination level of 104 spores/g Fc values of 11.0 and 15.0 were necessary to completely eliminate the same bacteria, respectively. Addition of 0.4 % benzoic acid resulted into reduction of the Fc – value from 16.0 to 13.0 for the elimination of B. stearothermophilus at 106 spores/g contamination level. Adding the same amount of citric or acetic acid was enough to lower the heating value further to 11.0. Potassium sorbate was ineffective in increasing the heat sensitivity of B. stearothermophilus even at a concentration of 4 % in the minced meat. It was concluded that the heating effects (Fc – values) recommended for the production of tropical stable and safe meat products are applicable only for highly contaminated raw meat. Fc – values of 16 and above given by some authors seem to be on the higher side. Observing hygienic practices in handling of the raw meat could significantly (

The quality of water in small community supplies of Kingolwira village, Morogoro, Tanzania

Tanzania Health Research Bulletin, 2007; 9 (1): 56-60.Water quality is an important aspect in human health, as the majority of infectious diseases that cause morbidity and mortality in population are water related. The present study was undertaken to assess the quality of water in Kingolwira, Morogoro Rural District, Tanzania. Water was collected from different sites in the village and analysed for a period of six months. Physical, chemical and microbiological qualities of water were examined. The pH of the water ranged from 7.02 to 7.20 and the water temperature ranged from 25.70C to 27.00C. The total dissolved solids of the water samples ranged from 110 to 510 ppm. The water contained considerable levels of lead and copper ranging from 0.034 to 0.090 ppm and 0.022 to 0.030 ppm, respectively. Total water hardness ranged from 19.60 to 228.10 ppm as calcium carbonate. The total viable counts and faecal coliform counts ranged from 2.75x103 to 5.4 x 103 c.f.u/ml and 0.93 x102 to 2.1x102 counts/100ml, respectively. Overall, water supplies in the village were judged as of poor quality. Water is usually used for domestic purposes including cooking, drinking, washing and preparation of infant foods without any treatment. In conclusion therefore, water in Kingolwira village is of poor quality and needs to be treated before consumption. Theres is also a need for the rural population to be educated on hazards of using untreated water. In general, sanitary facilities in rural areas in Tanzania need to be improved in order to avoid health hazards

Molecular improvement of food functional properties of Soybean glycinin by protein engineering

Tanzania Journal of Agriculture Science 1998. Vol 1(1): pp 50-56A study was made to elucidate the three dimensional structure of soybean glydnin which is one of the dominant storage proteins of soybean seeds. Previously, the twodisulphide bonds Cys12-Cys45 and Cys88-Cys298 in the proglydnin AlaBlb subunit were deleted andCys residues were replaced by Gly and Ser by Oligonucleotide-directed mutagenesis. The mutant proglycinins Gly12, and Ser88 showed to have better gelation and emulsifying properties. The mutant proglydnins were crystallised along with the normal proglycinin (AlaBlb -3) and subjected to X-ray structure analysis in an attempt to determine their structure-junction relationships. The crystals diffracted X-ray to a resollttion limit of 2.9 - 3.4A on stillphotographs and belongto the tetragonal system, space group P41 or P43 with cell dimensions of a = b·= 114.3 - 115.2A. and d;= 145.7 - 147.1A with 3 protomers per asymmetric unit. Further refinement data for the' crystals of normal prpglycinin were obtained by multiple isomorphous replacement and solvent flattening techniques. The tri1?ler dimensions of tlie normal proglydnin as determined at 6A were 93A by 93A with·the thickness of 36A

Comparative evaluation of different methods of extraction and purification used in technical enzyme production from microorganisms

Tanzania Journal of Agricultural Sciences, 1998; I (2): 141-148A stlldy was conducted to compare the efficiency of two methods of microbial cell separation and enzyme purification using penicillin-G-acylase (PGA) from Escherichia coli. The efficiency of two methods of ceJ[ separation; centrifugation and cross flow filtration (CFF) were compared. The CFF method was found to have both higher separation efficiency and enzyme yield than centrifugation method. Centrifugation method gave a separation efficiency of 98.5% with enzyme yield of94 % whereas CFFmethod resulted in 100% separation efficiency and enzyme yield of98.8%. The Escherichia coli cells were disrupted by high pressure homogenization (HPH),and the disrupted cells were purified using two different techniques. Technique I was a combination of cross-flow-diafiltration (CFD) , ultrafiltration (UF) and heat/pH-shift treatments. This technique resulted in 47% enzyme yield with a purification factor of 12. Technique II which involved two extraction steps by' aqueous two - phase system (APS) coupled with UF resulted in 62 % enzyme yield with a pu;ificationfactor of 4. Technique I was therefore much better than techriique Il in purifying the enzyme. For higher enzyme yield, technique II would seem to be a better one than technique I