Faculty of Science Engineering and Technology

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    Application of Simplex Lattice Designin Watermelon Production
    (Chuka University, 2019) Muriithi,Dennis K.
    This paper discusses the use of Simplex Lattice Design approach to plan the experiment for yield of watermelon with an overall objective of optimizing the multiple responses of watermelon to organic manure. Multiple linear regression models have been adopted to express the output parameters (responses) that are decided by the input process parameters. Poultry manure, cow manure and goat manure were the independent variables to optimizethe response values of interest that includes; watermelon fruit weight, number of fruits of watermelon per plant. Mixture experiments are appropriate to use when a researcher wishes to determine if synergism exists in mixing components which increases productivity. Three-component design presented in this study illustrated how to applymixture designs inagricultural research. Mathematical Model evolved for response showthe effect ofeach input parameter and its interaction with other parameters, depicting the trend of response. From, the equation of fruit weight and number of fruits, it canbe concluded that goat manure has a more important role on watermelon production in the current study. Conclusively, the current study attained the optimal condition of 17.68 ton/Ha, 11.69 ton/Ha and 19.16 ton/Ha of poultry manure, cow manure and goat manure respectively, would guarantee the farmer a maximumyield of22.13kgfruit weightof watermelonper plantand 7.74≈8 Fruitof watermelonper plant. The study exemplified that the development of statistical models for crop production can be useful for predicting and understanding the effects of experimental factors.
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    Microbial quality and safety of ready-to-eat street-vended foods sold in selected locations in Kenya
    (Journal of Food and Dietetics Research, 2022-01-27) Johnson Mwove1,2 , Samuel Imathiu3 , Irene Orina3 , Paul Karanja3
    Objectives: Street-vended foods (SVFs) are a major contributor to foodborne diseases, especially in developing countries, where their sale is largely uncontrolled. Foodborne diseases have often been linked to high morbidity and mortality in some developing countries such as Kenya, demonstrating their public health and societal significance. The objective of this study was to determine the microbial quality and safety of ready-to-eat (RTE) foods sold in selected locations within Thika town in Kiambu County, Kenya. Material and Methods: A total of 199 food samples consisting of cereals, sliced fruits, salads, groundnuts, tubers, fruit juices, boiled deshelled eggs, smokies, and sausages were randomly collected for microbial analysis. Determination of total viable count (TVC), total coliform count (TCC), yeast and molds count (YMC), Escherichia coli counts, Staphylococcus aureus counts as well as the presence of Salmonella spp., and Listeria monocytogenes were determined following standard microbiological methods. Results: Results revealed that plant-based foods had significantly (P < 0.01) higher TVC, TCC, YMC, and S. aureus counts compared to animal-based foods. The levels of TVC, TCC, YMC, E. coli, and S. aureus ranged from 6.590 ± 1.020 to 3.377 ± 1.764, 5.567 ± 2.233 to 1.594 ± 2.299, 5.052 ± 1.201 to 1.595 ± 2.146, 2.033 ± 1.229 to 0.000 ± 0.000, and 5.972 ± 1.170 to 1.888 ± 1.660 Log10 CFU/g, respectively. At least nine food samples were contaminated with E. coli although the chance for contamination was significantly (P = 0.0002) higher (15 times) in plant-based foods compared to animal-based foods. At least one sample in each food type was contaminated with S. aureus with contamination levels above 1.888 ± 1.660 Log10 CFU/g. Salmonella spp. was only detected in boiled arrowroots (25%), boiled deshelled eggs (5.6%), French fries (5.6%), juices (5.0%), and cereals (11.1%), while L. monocytogenes were not detected in any food sample. Conclusion: These findings demonstrate that RTE SVFs sold in this region constitute a potential health hazard to consumers because of the presence of Salmonella spp., and high counts of E. coli and S. aureus. These foods are, therefore, microbiologically unsafe and unsuitable for human consumption as they may cause foodborne disease outbreaks.