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1. Improving Food Production by Understanding the Effects of Intercropping and Plant Population on Soybean Nitrogen Fixing Attributes
Elijah M.W. Akunda
Department of Botany
University of Nairobi, P.O Box 30197
Abstract
This paper quantifies the effects of population density and intercropping on the development and growth of nitrogen fixing attributes of soybean and explains how these attributes influence food through yielding process. Information for this study was obtained from a field study conducted over two rainy seasons comprising of the short and long rains in Kenya. Inoculated soybean was grown in two combinations; sole and intercropped with sorghum at three levels of population densities; 66, 666; 83, 333 and 111, 111 plants ha-1. Estimates of nodule mass, position, density, number, effective nodules and nodulation frequency were monitored at various intervals during the growing season. The responses of nitrogen fixing attributes of soybean varied with cropping pattern, density, stage of growth and the growing season. Intercropping caused decreases in nodule biomass at 21 days after planning (DAP), number of nodules, and nodulation frequency at the 1st, harvest of the 3rd season and at the 1st, 2nd and 3rd harvests of the 4th growing seasons. Significant increases in dinitrogen fixing attributes within intercropped stands were demonstrated for nodule position, percent effective nodules, and percent nodulation frequency at the 2nd and 4th harvests of the 3rd growing season. Influences of density on nodulation frequency during the 4th harvest were highly variable. Density and inter-cropping interactions caused significant decreases for nodule biomass at 21 DAP, percent nodulation at the 4th harvest during the 3rd growing in contrast to those decreases noted at the 2nd, 3rd and 4th only. The study indicates that for soybean yield, any management factors that cause a reduction in nitrogen fixing attributes are crucial to improving yield of soybean. There is therefore need to study the physiology of dinitrogen fixing attributes in order to understand yield processes.
3. Physico-chemical Properties of Pure Water Samples in South Western Nigeria
Ashaye O. A*, Couple A. A, Afolabi O.O
and Fasoyiro S. B
Institute of Agriculture Research and Training P. M. B. 5029
Moor Plantation, Ibadan
*Corresponding author
Abstract
Pure water samples were evaluated for their physicochemical properties. Samples 5 gave higher values of K(15 ppm), mg(6.75 ppm) and Zn (0.04 ppm). While sample 6 was high in P (4.85 ppm). The pH value of samples 8 (7.65) was also higher. Biochemical Oxygen Demand (B.O.D), Chemical Oxygen Demand (COD) and Total Suspended Matter were not detected in all the samples. However the total dissolved solids of sample 3 (0.012%) was very low. The colour of samples 1, 2, 4, 5, 7 and 8 are not significantly different from each other, while samples 3 and 6 are significantly different from each other. The taste of samples 2 and 5 were objectionable while the odours of samples (2-8) were objectionable. It is apparent from this study that the quality of the pure water samples could improve if a better water treatment is adopted.
Key words: Pure water, physicochemical and treatment
4. Response of Common Bean to Rhizobium Inoculation and Fertilizers.
1Amos A. O. Musandu and 2Ogendo O. Joshua.
1Department of Soil Science, Egerton University,
2Department of Agronomy, Egerton University,
P.O. Box 536, Njoro, Kenya.
Abstract
Common bean (Phaseolus vulgaris) yields in Western Kenya are low and this has been attributed to low soil fertility. Field trials were conducted in farmers fields in Ukwala Division of Siaya District in Kenya during the long rains of 1998 and 1999 to determine the potential for improving bean yields through Rhizobium inoculation, and fertilizer N and P applications. The three factors: Rhizobium inoculation at two levels and fertilizers-N and P each at three levels were factorially combined to give 18 treatments. The treatments were laid out in a randomised complete block design with a split-plot structure and three replications. A popular local bean variety Okuodo was used as the test crop. During the 1998 long rains season, P significantly (P=O.05) increased the stand count after emergence, pod number per plant and the bean grain yields. Seed number per plant alone was significantly increased by fertilizer-N application. Significant interaction effects (P=O.05) were observed for NXP on the stand count after emergence and for Rhizobium inoculation XP on stand count after emergence, stand count at harvest and the bean grain yields. Rhizobium inoculation alone did not significantly affect any of the measured variables in both seasons. In 1999, only the bean grain yields were determined and were significantly (P=O.05) increased only by fertilizer P applications.
5. A Microbiological and Nutritional Evaluation of the West African Dried Meat Product, Kilishi
M. J. Jones1, V. N. Tanya2* , C. M.F. Mbofung3, D. N. Fonkem2, D. E. Silverside1
1Natural Resources Institute, Central Avenue, Chatham
Maritime, Kent ME4 4TB, England
2Institute of Agricultural Research for Development, Regional
Centre of Bambui, P.O. Box 51 Bamenda, Cameroon
3Department of Food Science and Nutrition, University of
Ngaoundere, P.O. Box 455 Ngaoundere, Cameroon
* Corresponding author
Abstract
The quality attributes of Kilishi, a West African dried meat product were studied over an eight week storage period comparing traditional production and packaging systems with a potassium sorbate treatment system and simple modern packaging. Changes in chemical composition and microbiological counts are reported. Moisture and water activity results indicated that the experimental Kilishi was sufficiently dried to minimise microbial growth. Fat oxidation levels measured by free fatty acids (FFA) (%) on extracted fats were unacceptably high (>1.2-2.1%) and may be a reflection of the quality of the groundnut and its oil in the ingredients. Processing of beef into Kilishi appears to lead to a decrease in mineral availability. Results suggest that treatment of Kilishi with 10% (w/v) potassium sorbate confers a degree of protection of the product from mould contamination. Aflatoxin levels far exceeded all established safe limits and are thought to be due to the use of pre-contaminated groundnut, as mould growth levels in Kilishi were very low.
Key-words: aflatoxins, dried meat, food preservative, kilishi, potassium sorbate.
6. Effect of Parboiling on Physico-chemical Qualities of Two Local Rice Varieties in Nigeria
1B. O. Otegbayo*, 2F. Osamuel, 3 J. B. Fashakin,
1 Department of Food Technology, University of Ibadan, Ibadan,
Nigeria
2 Department of Human Nutrition, University of Ibadan, Ibadan,
Nigeria
3 Department of Food Science and Technology, Obafemi Awolowo
University, Ile-Ife, Nigeria
*corresponding author
Summary
Two varieties of local rice in paddy form were used for this study. The rice were collected from local farmers at Okemesi Ekiti in Ekiti State of Nigeria (western Nigeria). The rice were divided into halves, one half was processed by Parboiling, Drying and Milling, the other half was processed by Drying and Milling only.
The result from the study showed that parboiling affected the physico-chemical qualities of the rice varieties. There were differences in the physical dimension, appearance, colour, water absorption, cooking time, amylose, protein, fat and carbohydrate contents of the parboiled and non-parboiled rice samples. Varietal differences also exist between the rice samples.
Parboiling reduced the breakage, fat, protein and amylose content of the rice while the cooking time, water uptake and thiamine contents were increased. It can therefore be inferred that parboiling which has been the means of processing rice in Nigeria can be a way of improving vitamin content and milling properties of rice and should attract the interest of food technologists and food processors to develop the rice industry.
7. Compositional Attributes of the Calyces of Roselle (Hibiscus sabdariffa L.)
Babalola, S.O.1 Babalola, A.01 and Aworh, O.C2.
1National Horticultural Research Institute, P.M.B. 5432,
Idi-Ishin, Ibadan, Nigeria.
2Department of Food Technology, University of Ibadan, Ibadan,
Nigeria
Abstract
In this study, chemical and mineral composition of the calyces of green, red and dark red roselle were evaluated. There was no significant difference in crude protein of green (17.9%) and red (17.4%) coloured roselle calyces. Crude fibre (11.2%), ascorbic acid (86.5mg/100g) and sodium (9.5mg/100g) contents of green coloured calyx were significantly higher than other calyx samples. However, dark red calyx was significantly higher in ash (6.8%) and potassium (2320mg/100g) contents than the other two calyces. Also, there was no significant differences in calcium, magnesium and zinc contents of red and dark red coloured roselle calyces at P<O.05.
Roselle calyces appeared to be cheap source of vegetable protein, fat and minerals therefore its consumption should be encouraged.
Key words: Roselle calyces, chemical analysis.
8. The Antioxidant Property of Aframomum danelli Spice in Oils
Fasoyiro S. B1* Adegoke G. O2, Obatolu V.A1 , Ashaye O1 and Aroyeun S.O3
1Institute of Agricultural Research and Training, Obafemi
Awolowo University, Moor Plantation, P.M.B. 5029, Jbadan, Nigeria
2 Department of Food Technology, University of Ibadan, Ibadan.
3.Cocoa Research Institute ofNigeria, Ibadan.
*corresponding author
Abstract
A study was carried out on the antioxidant property of Aframomum danelli extract in palm oil and soybean oil. The activity of A. danielli extract was compared with those of other antioxidants of other plant sources, rosemary extract and d-tocopherol, at different concentrations. A. danielli was as active as rosemary plant extract in reducing rate of peroxide formation in soybean oil at concentrations of 200 ppm and 300 ppm . A danielli was much more effective than tocopherol in reducing peroxidation in soybean oil and palm oil at the higher concentrations except at 50 ppm.
Keywords: Antioxidant activity, Aframomum danielli spice, oils.
9. Effect of Modified Atmosphere Packaging on Microbiological, Physiological and Chemical Qualities of Stored Carrot
1Tilahun Seyoum Workneh*, 2G. Osthoff, 3M.S. Steyn
1Alemaya University, Department of Agricultural Engineering,
P.O. Box 138, Dire Dawa, Ethiopia.
2, 3 Department of Food Science, Faculty of Agriculture, The
University of Free State, P.O. Box 339, Bloemfontein 3900,
South Africa
*Corresponding author
Abstract
Optimum packaging film for carrots should lead to low condensation, but preventing moisture loss, and maintain optimum gas composition during the storage period. In this study, carrots were packaged in polypropylene (PP) and low density polyethylene (LDPE) films and stored at 0¼C and ambient temperature (15-25¼C). After 7 days of 0¼C storage headspace O2, CO2 and N2 concentrations were 11.85%, 13.38%, and 6.69% for PP films and 3.39%, 3.24% and 4.77% for LDPE films. On the other hand, after 7 days of ambient temperature storage O2, CO2 and N2 concentrations were 6.78%, 28.31%, and 16.15% for PP films and 6.41%, 5.19% and 5.28% for LDPE films. The higher the CO2 content of the headspace the more the sucrose content decreased while the glucose and fructose content changed slower. A general decrease of the sugars (sucrose, glucose and fructose) was observed for all samples packaged in PP. The free sugars in carrots were observed to decrease at a slower rate for packaging in LDPE. Based on these results, it was concluded that LDPE film allowed lower respiration rates and is preferred to the PP material. The number of total aerobic microorganisms was higher in packages stored under ambient conditions than in those stored at 0ºC temperature. The lowest counts were observed in the least permeable packaging film (PP) up to day 14. The total number of populations of coliform was higher with PP and LDPE films stored under ambient conditions as compared to those stored at OºC. Packaging films with relatively higher permeability to O2 and CO2 are preferred for maintaining normal respiration of carrots without the occurrence of secondary decomposition during storage. Modified atmosphere packaging combined with low temperature storage of carrots (about 1¼C) reduces both biological and biochemical activities resulting in improved keeping quality.
Key words/phrases: Modified atmosphere packaging, polypropylene, low density polyethylene