Browsing by Author "Chove, B. E."
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Item Comparative evaluation of different methods of extraction and purification used in technical enzyme production from microorganisms(Tanzania J. Agric. Sc) Gidamis, A. B.; Nnko, A.; Shayo, N. B.; Chove, B. E.; Kroner, H. K.Item Comparative evaluation of different methods of extraction and purification used in technical enzyme production from microorganisms(Tanzania J. Agric. Sc, 1998) Gidamis, A. B.; Nnko, A.; Shayo, N. B.; Chove, B. E.; Kroner, H. K.A 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.Item Copper and Lead levels in two popular leafy vegetables grown around Morogoro Municipality, Tanzania(Tanzania Health Research) Chove, B. E.; Ballegu, W. R.; Chove, L. M.Item Copper and Lead levels in two popular leafy vegetables grown around Morogoro Municipality, Tanzania(Tanzania Health Research, 2006) Chove, B. E.; Ballegu, W. R.; Chove, L. M.A study was carried out to determine the levels of two heavy metals, Lead (Pb) and Copper (Cu), in two popular leafy vegetables grown around Morogoro Municipality in Tanzania. Vegetable samples of Pumpkin leaves (Cucurbita moschata) and Chinese cabbage (Brassica chinensis) were collected from three sites and analysed for their concentrations of the two metals using an Atomic Absorption Spectrophotometer. The three sites, namely Mazimbu, Kihonda and Towelo are located within a 10 km perimeter. The site selection was based on the anticipated levels of contamination of the water used for irrigation. The results showed that the levels (mg/100g dry weight) ranged from 0.885 to1.39 for Copper and 0.05 to 0.315 for Lead. The levels of Lead and Copper varied between the vegetable varieties and from site to site. Vegetables from Mazimbu showed higher concentration levels of the two metals compared to the other sites in both varieties. Towelo vegetables had relatively low concentrations. There was a significant difference (P<0.05) in levels of the two metals across the sites but there was no significant difference (P>0.05) in the levels of Copper between the two vegetable varieties from all the three sites. There was a significant difference (P<0.05) in the levels of Lead between the vegetable varieties. The levels of both Lead and Copper in the two vegetables were found to be below the maximum permissible levels recommended by FAO/WHO for the two metals in vegetables.Item Effect of germination and autoclaving of sprouted finger millet and kidney beans on cyanide content(Tanzania Journal of Health Research) Chove, B. E.; Mamiro, P. R. S.Item Effect of germination and autoclaving of sprouted finger millet and kidney beans on cyanide content(Tanzania Journal of Health Research, 2010) Chove, B. E.; Mamiro, P. R. S.Cyanide contents of locally purchased brown finger millet (Eleusine corocana L. Gaertner) and brown speckled kidney bean seeds (Phaseolus vulgaries var. Rose Coco) were determined using raw, germinated and autoclaved samples. The aim was to establish the extent of cyanide content increase resulting from the germination process and the effectiveness of the autoclaving process on the reduction of cyanide levels in the samples, for safety considerations. Autoclaving was carried out at 121°C for 20 minutes. It was found that germination increased the cyanide content by 2.11 to 2.14 fold in finger millet for laboratory processed samples. In the case of kidney beans the increment was 1.76 to 1.77 fold for laboratory samples. The increments for field processed samples were in the same range as those for laboratory samples. Autoclaving reduced the cyanide content to between 61.8 and 65.9 % of the original raw contents for finger millet and between 56.6 to 57.8% in the case of kidney beans. The corresponding reductions for field samples were also found to be within the same ranges as the laboratory processed samples. It was concluded that autoclaving significantly reduced the cyanide levels in germinated finger millet and kidney beans.Item Emulsifying properties of soy protein isolates obtained by microfiltration(Society of Chemical Industry) Chove, B. E.; Grandison, A. S.; Lewis, M. J.Item Influence of storage temperature and time on the physicochemical and bioactive properties of roselle-fruit juice blends in plastic bottle(Food Science & Nutrition) Mgaya-Kilima, B.; Remberg, S. F.; Chove, B. E.; Wicklund, T.Item Physio-chemical, mineral composition and antioxidant properties of roselle (hibiscus sabdariffa l.) Extract blended with tropical fruit juice(Ajfand) Mgaya, K. B.; Remberg, S. F.; Chove, B. E.; Wicklund, T.Item Proximate composition, bread characteristics and sensory evaluation of Cocoyam-Wheat composite breads(Ajfand) Mongi, R. J.; Ndabikunze, B. K.; Chove, B. E.; Mamiro, P.; Ruhembe, C. C.; Ntwenya, J. G.Item Proximate composition, bread characteristics and sensory evaluation of Cocoyam-Wheat composite breads(Ajfand, 2011) Mongi, R. J.; Ndabikunze, B. K.; Chove, B. E.; Mamiro, P.; Ruhembe, C. C.; Ntwenya, J. G.This study was carried out to investigate proximate composition, bread characteristics and sensory evaluation of cocoyam-wheat composite breads at different levels of cocoyam flour substitution for human consumption.A whole wheat bread (WWB) and cocoyam-composite breads (CCB1,CCB 2 and CCB 3) were prepared in triplicate at 0, 10, 20 and 30% levels of cocoyam flours substitution respectively and assessed for proximatecomposition, bread characteristics and sensory attributes.The results indicate that carbohydrate, crude fiber, and ash contents of the cocoyam-composite breads increased significantly (p<0.05) while the moisture and protein contents decreased significantly with progressive increase in the cocoyam flour substitution. The significant (p<0.05) highest ash, fibre and carbohydrate values of 1.61, 1.54 and 70.40 g/100g dm respectively were observed in 30% cocoyam-wheat composite bread compared to lowest values of1.15, 0.29 and 63.25 g/100g dm, respectively in 100% wheat bread. The significant (p<0.05) higher moisture and protein values of 20.99 and 12.54 g/100g dm were observed in 100% wheat bread compared to lowest values of 17.31 and 9.04 g/100g dm, respectively in 30% cocoyam-wheat composite bread. Bread characteristics showed that, the loaf weight of cocoyam composite breads increased significantly (p<0.05) while loaf volume and specific loaf volume decreased significantly (p<0.05) with increasing cocoyam flour substitution The significant (p<0.05) highest loaf weight of 229.33 g was observed in 30% cocoyam-wheat composite bread compared to 208.33, 221.67 and 225 g observed in 100% wheat bread, 10 and 20% cocoyam-wheat composite breads respectively. The highest loaf volume and specific loaf volume of 800 and 3.49 cc were observed in 100% wheat bread compared lowest values of 580 and 2.78 cc respectively observed in 30% cocoyam-wheat composite bread. The sensory evaluation showed no significant (p>0.05) differences in sensory attributes of taste, aroma and acceptability between the 100% wheat and 10% cocoyam-wheat composite breads (p<0.05). In conclusion, this study has shown that the use of cocoyam flour in bread making is feasible and that incorporation of up to 10% of the flour into wheat flour produced acceptable bread with similar taste and aroma comparable to 100% wheat bread. Nevertheless, it is important to consume this bread with other protein rich diet in order to supplement the reduction resulted from substitution.Item The quality of water in small community supplies of Kingolwira village, Morogoro, Tanzania(Tanzania Health Research) Shayo, N. B.; Chove, B. E.; Gidamis, A. B.; Ngoma, O. B.