Food Processing

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Assessment, views and challenges of zinc and iron fortification of locally milled maize flour sold in Nairobi, Kenya
(Moi University, 2020) Mutuma, Ireen Kathure
Introduction: Low nutrient intake of Zinc and Iron is a global problem affecting the health and social economic wellbeing of world population. There is an advocacy for food fortification as one method of dealing with these two serious micronutrient deficiencies. Kenya has not been left behind. A legal notice of June 2012 made fortification of maize flour with zinc and iron mandatory for all maize millers. Limited studies have been done to evaluate compliance to the Kenyan gazette notice on micronutrient fortification standards for maize flour. Objectives: Assessment of Iron and Zinc concentration in maize flour, consumers views and miller challenges on fortification of locally milled maize flour, sold in Nairobi, Kenya. Methods: A cross sectional survey approach was used. The study was carried out in Nairobi County, Kenya. 35 Samples of fortified maize flour were randomly purchased to give a representative sample. Atomic Absorption Spectrometry was used to analyze amounts of Zinc and Iron in the maize flour samples. 384 consumers were interviewed from Nairobi County. Four maize flour millers and a Kenya Bureau of standards personnel responded to the questionnaire. Zinc and iron levels were compared against recommended fortification standards. Data on consumers was extracted, entered on excel spreadsheet and imported into R statistical software package for analysis. Data is presented in prose, charts, and tables. Results: From the study, of the 35 samples analyzed, overall, 14.29% of the samples met the minimum legal requirement of zinc and iron. The amount of iron ranged between1.08 ppm to 19.02 ppm against a minimum of 15ppm, the amount of zinc ranged from 10.64ppm to 56.25ppm against a minimum of 20ppm. Pearson’s correlation between zinc and iron fortification, was negative at a coefficient of 0.487787. Of the respondents who had knowledge on fortification, 61 % were female. There existed a positive relationship (p-value = 0.0248) between knowledge of fortification and age bracket. Consumers believed fortification improved their health at 66%. Major reasons given for fortification non-compliance were corruption and cost at 40% and 30% respectively. Although the media played a major role in creating fortification awareness at 41 %, 62.9% of respondents were not aware of the mandatory maize flour fortification with Iron and Zinc. Of the four millers interviewed, it was clear, there are no government incentives to support the mandatory fortification. Conclusion: The study showed that Maize flour available for public consumption in Nairobi County is not adequately fortified. Consumer knowledge on mandatory fortification to be increased. Millers are not adequately prepared to fortify maize flour adequately. Recommendations: The fortification process to be integrated into the overall food safety mechanisms to ensure conscious and constant monitoring during production. Consumer awareness to be created on the benefits of consuming fortified foods. The government to routinely publish the list of products that are complying and taking disciplinary actions on milers who do not comply. Government incentives such as subsidized costs of laboratory analysis would ensure increased monitoring.
Assessment, views and challenges of zinc and iron Fortification of locally milled maize flour sold in Nairobi, Kenya
(Moi University, 2020-10) Mutuma, Ireen Kathure
Introduction: Low nutrient intake of Zinc and Iron is a global problem affecting the health and social economic wellbeing of world population. There is an advocacy for food fortification as one method of dealing with these two serious micronutrient deficiencies. Kenya has not been left behind. A legal notice of June 2012 made fortification of maize flour with zinc and iron mandatory for all maize millers. Limited studies have been done to evaluate compliance to the Kenyan gazette notice on micronutrient fortification standards for maize flour. Objectives: Assessment of Iron and Zinc concentration in maize flour, consumers views and miller challenges on fortification of locally milled maize flour, sold in Nairobi, Kenya. Methods: A cross sectional survey approach was used. The study was carried out in Nairobi County, Kenya. 35 Samples of fortified maize flour were randomly purchased to give a representative sample. Atomic Absorption Spectrometry was used to analyze amounts of Zinc and Iron in the maize flour samples. 384 consumers were interviewed from Nairobi County. Four maize flour millers and a Kenya Bureau of standards personnel responded to the questionnaire. Zinc and iron levels were compared against recommended fortification standards. Data on consumers was extracted, entered on excel spreadsheet and imported into R statistical software package for analysis. Data is presented in prose, charts, and tables. Results: From the study, of the 35 samples analyzed, overall, 14.29% of the samples met the minimum legal requirement of zinc and iron. The amount of iron ranged between1.08 ppm to 19.02 ppm against a minimum of 15ppm, the amount of zinc ranged from 10.64ppm to 56.25ppm against a minimum of 20ppm. Pearson’s correlation between zinc and iron fortification, was negative at a coefficient of 0.487787. Of the respondents who had knowledge on fortification, 61 % were female. There existed a positive relationship (p-value = 0.0248) between knowledge of fortification and age bracket. Consumers believed fortification improved their health at 66%. Major reasons given for fortification non-compliance were corruption and cost at 40% and 30% respectively. Although the media played a major role in creating fortification awareness at 41 %, 62.9% of respondents were not aware of the mandatory maize flour fortification with Iron and Zinc. Of the four millers interviewed, it was clear, there are no government incentives to support the mandatory fortification. Conclusion: The study showed that Maize flour available for public consumption in Nairobi County is not adequately fortified. Consumer knowledge on mandatory fortification to be increased. Millers are not adequately prepared to fortify maize flour adequately. Recommendations: The fortification process to be integrated into the overall food safety mechanisms to ensure conscious and constant monitoring during production. Consumer awareness to be created on the benefits of consuming fortified foods. The government to routinely publish the list of products that are complying and taking disciplinary actions on milers who do not comply. Government incentives such as subsidized costs of laboratory analysis would ensure increased monitoring
Bioethanol Production from Enzymatic Hydrolysis of Rio Sweet Sorghum Bagasse Grown in Kenya
(The International Journal of Science & Technoledge, 2018-05-12) Mukabane, Bonface G.; Thiongo, George; Gathitu, Benson B.; Murage, Hunja; Owino, Willis O.
Sweet sorghum (Sorghum bicolor (L) Moench) is a crop analogous to sugarcane with similar accumulation of sugars in its juicy stems and has a high yield of green biomass (20-30t/ha), and a huge amount of lignocellulosic residue are produced as byproduct of sweet sorghum. The present study was undertaken with the objective of determining the potential of sweet sorghum bagasse (SSB) to produce bioethanol hence find a sustainable source of biofuel and spur economies of rural areas and also mitigate climate change. Sixteen sweet sorghum varieties namely: Madhura, Theis, Rema, Ramanda, Rio, CMSXS633, CMSXS644, SPV1411, IESV91018LT, IESV92008DL, IESV92038/2SH, IESV93042SH, were planted at the Jomo Kenyatta University of Agriculture and Technology research farm. Rio sweet sorghum with the highest sucrose purity was harvested and juice extracted. SSB was dried, comminuted and pretreated with phosphoric acid and alkaline hydrogen peroxide. The pretreatment with alkaline hydrogen peroxide and phosphoric acid led to 63.40% (wt/wt) and 49.12% (wt/wt) yield of glucose per gram substrate. Hydrolysis was by cellulase produced by Trichoderm reesei and the % theoretical enzymatic sugar yield after 72h was 50%, 78% and 88% for untreated, phosphoric acid pretreated and sodium hydroxide pretreated bagasse, respectively. Fermentation was by baker's yeast and the results were 15.33%, 40.45% and 59.44% of the theoretical yield for untreated, sodium hydroxide pretreated and phosphoric acid pretreated bagasse, respectively. The rate of ethanol production was respectively, 0.001g/l.h, 0.016g/l.h and 0.019g/l.h for the untreated, phosphoric acid pretreated and NaOH pretreated bagasse. Therefore, bioethanol can be produced from SSB but further research should be done to increase the yield before piloting and later commercialization of the process.
Cellulose Nanofibrils from Sugarcane Bagasse as a Reinforcing Element in Polyvinyl Alcohol Composite Films for Food Packaging
(Multidisciplinary Digital Publishing Institute, 2022) Otenda, Brian Victor; Kareru, Patrick Gachoki; Madivoli, Edwin Shigwenya; Maina, Ernest Gachui; Wanakai, Sammy Indire; Wanyonyi, Wycliffe Chisutia
Due to a high aspect ratio and enhanced mechanical strength, cellulose nanofibrils can be used as reinforcing elements in biocomposite films. In this study, cellulose nanofibrils were isolated from sugarcane bagasse using TEMPO-mediated oxidation and used to reinforce polyvinyl alcohol (PVA) films. The carboxyl group content, functional groups, crystallinity, thermal properties, and morphology of the nanofibrils were investigated. The influence of TOCNF content on the transmittance, swelling, and tensile strength of PVA-TOCNF films were investigated by varying the TOCNF content of PVA films. The fibrils had a carboxyl content of 12.2 ± 0.6 mg/g CE due to the presence of carboxylic groups, an increased degree of crystallinity, and highly porous nanofibrils with lengths between 150 nm and 600 nm. Incorporation of the isolated fiber on PVA films increased the swelling capacity, tensile strength, and UV absorption but a decrease in the solubility of the composite. An increase in the TOCNF content increased the tensile strength of the films with the highest tensile strength of 6.6 ± 2.2 kPa being observed when the TOCNF content was 30%. The improvement in films properties implies that the films can be used as a packaging material due to enhanced water absorption and light-barrier properties.
Cellulose Nanofibrils from Sugarcane Bagasse as a Reinforcing Element in Polyvinyl Alcohol Composite Films for Food Packaging
(Taylor and Francis, 2022) Otenda Brian Victor; Kareru Patrick Gachoki; Madivoli Edwin Shigwenya; Maina Ernest Gachui; Wanakai Sammy Indire; Wanyonyi Wycliffe Chisutia
Due to a high aspect ratio and enhanced mechanical strength, cellulose nanofibrils can be used as reinforcing elements in biocomposite films. In this study, cellulose nanofibrils were isolated from sugarcane bagasse using TEMPO-mediated oxidation and used to reinforce polyvinyl alcohol (PVA) films. The carboxyl group content, functional groups, crystallinity, thermal properties, and morphology of the nanofibrils were investigated. The influence of TOCNF content on the transmittance, swelling, and tensile strength of PVA-TOCNF films were investigated by varying the TOCNF content of PVA films. The fibrils had a carboxyl content of 12.2 ± 0.6 mg/g CE due to the presence of carboxylic groups, an increased degree of crystallinity, and highly porous nanofibrils with lengths between 150 nm and 600 nm. Incorporation of the isolated fiber on PVA films increased the swelling capacity, tensile strength, and UV absorption but a decrease in the solubility of the composite. An increase in the TOCNF content increased the tensile strength of the films with the highest tensile strength of 6.6 ± 2.2 kPa being observed when the TOCNF content was 30%. The improvement in films properties implies that the films can be used as a packaging material due to enhanced water absorption and light-barrier properties.
Characteristic effects of drying processes on bioactive compounds in african eggplant
(JKUAT, 2012) Mbondo, Naomi Nammaiyan; Prof. Willis O. Owino, PhD; Prof. Daniel N. Sila, PhD; Dr. Jane Ambuko, PhD
African eggplant (Solanum aethiopicum L.) is a rich source of bioactive compounds and functional constituents that are beneficial to human health. However, the short (3-5 days) shelf life can be a major cause of postharvest losses especially during peak harvesting season. Drying technology is a convenient way of producing shelf stable food products, but can lead to thermal degradation of available nutrients and bioactive compounds depending on the drying method and temperature conditions. Monitoring the changes in bioactive compounds is important for optimizing and choosing drying methods and conditions.The objective of this study was to investigate the effect of harvesting maturity on the drying characteristics; to determine the effect of four drying methods (solar, hot air oven, vacuum oven and freeze) on the retention of total phenolics, beta carotene, antioxidant capacity, vitamin C and lycopene; to determine the degradation kinetics of total phenolics, beta carotene and antioxidant activity during hot air oven and vacuum oven drying; and to establish consumer acceptability of the dried and reconstituted products through sensory evaluation. Five African eggplant (Solanum aethiopicum) accessions (sangawili, manyire green, S00047A, AB2 and aubergine blanche) were used in the study. Harvesting was carried out at two maturity stages defined by the peel shininess, colour and number of days between planting and harvest. Stage 1 maturity had a shiny peel while stage 2 maturity had a non-shiny peel. Samples were dried up to ~10% moisture content in a single layer. Random sampling was done at regular intervals as the drying process progressed. Subsequently, fresh and dried samples were analyzed for moisture content, total phenolics, beta carotene content, vitamin C, lycopene content and antioxidant capacity. Affective testing using 7 point hedonic scale was used for sensory evaluation through a consumer panel to establish the likability scores for the dried and reconstituted samples. The results showed that harvesting maturity significantly (p<0.05) effected the moisture content and the drying rate of the five accessions. Moisture content decreased from stage 1 maturity to stage 2 by up to 2.01% with the exception of AB2. The drying rates were higher for stage 1 maturity in comparison to stage 2. The drying time for stage 1 and stage 2 maturities was 360-840 and 360-960 minutes, respectively. In the fresh state, beta carotene, total phenolics and antioxidant activity ranged between 14.75-29.50 mg/100g db, 751.21-1363.95mg/100g gallic acid equivalent (GAE) db and 99.58-325.61mg/ml db percentage inhibition at 50% (IC50) value, respectively. The results showed a significant (p=0.001) positive correlation (r=0.822) between the total phenolics and the antioxidant equivalent ascorbic acid capacity. However, drying processes significantly (p<0.05) reduced the total phenolics, beta carotene and antioxidant capacity with freeze drying presenting the highest retention rate. Overall, 36.26 – 95.05% (total phenolics) and 31.44 – 99.27% (beta carotene) was retained during freeze drying. Lycopene was only detected in the dried samples of the accession manyire green. Also, vitamin C was undetected in both fresh and dried samples. The kinetics of degradation of total phenolics, beta carotene content and antioxidant activity followed a first-order reaction for both hot air oven and vacuum oven drying. The range of reaction rate constant was 0.018-0.067, 0.016-0.226, xx and 0.0237-0.453 h-1 for total phenolics, beta carotene and antioxidant activity, respectively. Activation energy range was 8.246-23.548, 15.994-60.845, 11.111-25.764 kJ/mol for total phenolics, beta carotene and antioxidant activity, respectively. Regarding the sensorial evaluation, it was not possible to clearly distinguish the sensory profiles of the five accessions statistically. The drying characteristics and degradation kinetics information from this study may be applied by farmers and industrialists in the development of optimum drying controls plan.
Composition of Polyphenols in Wheat Bread Supplemented with Pleurotus ostreatus Mushroom
(2015) Stella W. Ndung’u; Christina A. Otieno,; Calvin Onyango; Fredrick Musieba
Pleurotus ostreatus mushrooms were blanched, milled into flour and incorporated into wheat flour at 5, 10 and 15%. These composite flours, together with composite breads developed from these formulations were evaluated for polyphenols, namely flavones and isoflavones. Wheat flour and wheat bread were used as control samples. Extraction of polyphenols was done using ethanol as a solvent and analyzed using gas chromatographmass spectrometry. It was not possible to make bread with 15% mushrooms. Quantities of different flavones and isoflavones evaluated increased significantly (p<0.05) with increasing supplementation of mushroom flour in wheat flour. Composite breads were also observed to have higher contents of flavones and iso flavones as compared to bread prepared from wheat flour only. Composite flour with 15% mushrooms had highest quantities of flavones and isoflavones while composite bread with 10% mushroom flour had significantly higher (p<0.05) levels of these compounds. Caffeic acid was the most abundant amongst all the flavones analyzed in wheat mushroom blends while genistein was the most abundant isoflavone. Flavones and isoflavones in human nutrition protect against oxidative stress and also provide medicinal properties such as antimicrobial, antiviral and anticancer benefits. Pleurotus mushrooms are a good source of these important compounds hence incorporating them in daily diet like bread would ensure constant supplementation for improved health and nutrition.
Crystallinity, Thermal and Morphological Characteristics of Resistant Starch Type III Produced by Hydrothermal Treatment of Debranched Cassava Starch
(Wiley Online Library, 2009-11-25) Mutundi C.; Rost F.; Onyango C.; Henle D.; Rohm H.
Cassava starch was debranched using pullulanase and the linear glucans recrystallized by incubation at 60°C or by temperature cycling at 120/60°C, and further subjected to heat-moisture treatment (HMT). Resistant starch (RS III) contents increased from 21.4 g/100 g in the debranched starch (DS) to 67.3 g/100 g in the debranched starch incubated at 60°C (DRS) and 47.8 g/100 g in the debranched starch subjected to temperature cycling (DCS), and further to 84.8 g/100 g and 88.4% g/100 g in HMT-DRS and HMT-DCS, respectively. Total crystallinity varied between 31.4-59.8% and the crystalline type was C in DS and DRS and A in DCS, HMTDRS and HMT-DCS. The melting properties were characterized by broad endotherms, but the exact melting region and enthalpy were dependent on recrystallization method. The main endothermic peaks of DS and DRS occurred at 103.9 and 109.8°C, respectively, whereas DCS exhibited split endotherms at 113.6 and 138.1°C. Heat-moisture treatment broadened the endotherms and increased their enthalpies. Scanning electron micrographs revealed surface topography differences related to size and aggregation of individual crystalline bodies.
Debranched Cassava Starch Crystallinity Determination by Raman Spectroscopy: Correlation of Features in Raman Spectra with X-Ray Diffraction And 13C CP/MAS NMR Spectroscopy
(Carbohydrate Polymers, 2012-01-04) Christopher Mutungi; Lars Passauer; Calvin Onyango; Doris Jaros; Harald Rohm
Because starch crystallinity influences the physical, mechanical, and technological aspects of numerous starch-based products during production and storage, rapid techniques for its assessment are vital. Samples of different levels of crystallinity were obtained by debranching gelatinized cassava starch, followed by subjection to various hydrothermal treatments. The recrystallized products were further subjected to partial hydrolysis with a mixture of α-amylase and glucoamylase prior to freeze–drying. Crystallinities were determined using X-ray diffraction (XRD) and 13C CP/MAS NMR spectroscopy, and correlated with FT-Raman spectra features. XRD crystallinities ranged between 0 and 58%, and agreed with crystalline-phase fractions (R2 = 0.99) derived from the respective 13C CP/MAS NMR spectra. A strong linear correlation was found between crystallinities and integrated areas of the skeletal mode Raman band at 480 cm−1 (R2 = 0.99). With appropriate calibration, FT-Raman spectroscopy is a promising tool for rapid determination of starch crystallinity.
Development of market opportunities through post-harvest processing of the African indigenous vegetables in Tanzania
(African Journal of Business Management, 2017-09-14) Musebe, Richard; Karanja, Daniel; Rajendran, Srinivasulu; Kessy, Radegunda; Kansiime, Monica; Marandu, Damas; Samali, Silivesta; Nicodemus, Jacqueline; Nenguwo, Ngoni; Chiwanga, Ruth; Makuya, Peter
African indigenous vegetables (AIVs) have gained prominence in the recent past due to nutritional and health benefits. The low requirement for high value inputs has enabled low resource farmers to practice AIVs production. There have been improvements in the production of high quality AIVs seeds as well as more production of the AIVs leaf and fruits. As a consequence, there are occasional gluts of the AIVs leaf and fruit especially during the main production season. This study examined the challenges associated with production of processed AIVs and possible market opportunities using data from 10 AIVs processing groups and 21 key informants that were purposively selected. Data were analysed using descriptive statistics and thematic analysis. It was established that processors did not have the necessary skills, knowledge and training required for processing of AIVs in more economically attractive ways. There was no diversity in the processing methods and processed products. Types and sources of packaging materials were restricted in various respects. Processors did not have special storage facilities for the AIVs. The share of processed AIVs in the total consumption of the vegetables was 25%. Sixty percent of those interviewed stated that the demand for all types of processed AIVs was increasing. Many institutions were supporting processing of AIVs. Quality of processed AIVs was perceived to be same as that of the fresh AIVs. Consumers were willing to pay more money for better quality processed AIVs. In order to increase sales of processed AIVs there should be informal agreements, partnerships or contracts depending on the degree of relationship between processors and consumers to guarantee target markets. Tanzania Bureau of Standard (TBS) and Tanzania Food and Drugs Authority (TFDA) need to create awareness regarding the specific quality requirements for processed AIVs. Training should be provided on different processing methods and the range of products that could be produced for different consumers. There should be financial support and/or linking of processors with the different credit institutions. It is necessary to provide processing infrastructure and training on marketing of the processed products. Specific requirements for the premises, processing rooms and standards should be explained to the processors to assure the requisite quality. Product branding has to be undertaken especially at two levels, which are indicating the key attributes of AIVs on the packages and certification by TBS and TFDA as well as having their labels on the containers of the packed products. Key words: Vegetables, processors, quality, storage, demand, target markets.
Effect of Drying Lactic Acid Bacteria Fermented Uji on Its Pasting Properties and Content of Carboxylic Acids
(University of Nairobi Department of Food and Nutrition Technology, 1999-01-01) Onyango, Calvin; Okoth, Michael; Mbugua, Samuel
The effect of fermentation and drying on the pasting properties and carboxylic acids of pure flours of maize, finger millet and cassava and of composite flours of maize-finger millet and cassava-finger millet were studied. The pasting properties were measured between 30°C and 96°C in a Brabender Amylograph while carboxylic acids from the uji slurries were determined on thin layer chromatography plates coated with 0.25 mm silica gel. Irrespective of the treatment given, the cereal flours of maize, finger millet and the composite of maize-finger millet consistently had higher onset and peak gelatinization temperatures than pure cassava or the composite of cassava-finger millet. Also the latter two flours developed higher peak viscosities and disintegrated more rapidly after attaining the peak than either pure maize, finger millet or the composite of maize-finger millet. The higher viscosities of the root flours was also reflected in the higher swelling powers and solubility values at 85°C. Fermentation increased the viscosity of the slurries. The greatest increases were recorded by maize (500BU) and the composite of maizefinger millet (780 BU). Fermentation did not affect gelatinization temperatures except for the maize-finger millet composite whose gelatinization temperature decreased by 10°C. Fermentation and drying resulted in increased viscosity when compared to the non-fermented flours, except for the drum dried cassava-finger millet composite. For all the drum dried flours there was a spontaneous increase in viscosity at 30°C when the Brabender Amylograph was switched on. The drum dried flours absorbed about four times their own weight of water; and since the starch granules were pregelatinized, reconstitution in cold water was difficult, as the flour particles tended to lump together, getting wetted on the surface and inhibiting the penetration of water into the interior. In contrast, sun and cabinet dried flours absorbed about 1.9 times their own weight of water and formed smooth slurries in cold water. Fermentation increased total titratable acidity and fixed acidity of the slurries to about 3.9% and 3.6% respectively, while the pH declined from 5.5 to 3.9. On drying there were no significant changes in (p0.05) from the uji prepared from fermented and nondehydrated slurries.
Effect of Resistant Cassava Starch on Quality Parameters and Sensory Attributes of Yoghurt
(Current Research in Nutrition and Food Science, 2017-12-04) Mwizerwa, Herve; Abong’, George Ooko; Okoth, Michael Wandayi; Ongol, Martin Patrick; Onyango, Calvin; Thavarajah, Pushparajah
Resistant starch is known to impart a number of health benefits to consumers. It is therefore desirable to increase the content of resistant starch in popular foods such as yoghurt. The current research investigated the effect of cassava resistant starch synthesized by heat-moisture treatment of starch from I92/0057 cassava variety on physico-chemical properties and sensory attributes of yoghurt. Cassava starch rich in resistant starch was incorporated into yoghurt in the proportions of 0, 0.1%, 0.5% and 1%. Corn starch (0.6%) was used as control. Yoghurt was stored at 4oC for 21 days and the effect of starch modification on resistant starch content, viscosity, syneresis, total solids, acidity, lactic acid bacteria count and sensory properties were determined on weekly basis. Applying cassava starch rich in resistant starch into yoghurt in the proportions of 0.5% and 1% had significantly higher (p≤0.05) resistant starch content of yoghurt reaching 3.40 g/100 g and 5.58 g/100 g on day one and 1.92 g/100 g and 4.47 g/100 g on day 21, respectively. There was a significant correlation (p≤0.05) between resistant starch concentration and the physicochemical properties of yoghurt. Yoghurt treated with 1% resistant starch enriched cassava starch had the highest viscosity during cold storage which was determined as 2721.5 mPa s, mPa s, 2650.0 mPa s and 1034.5 mPa s at day 1, day 7, day 14 and day 21 respectively and it had the least syneresis (22.25%). Addition of cassava starch rich in resistant starch significantly increased (p≤0.05) the total solids content of yoghurt but did not significantly (P>0.05) change the sensory properties of yoghurt. The application of 1% of resistant starch enriched cassava starch as yoghurt thickener produces significant quantity of resistant starch in yoghurt with acceptable sensory and physico-chemical properties.
Effect of ridging and intercropping on sorghum productivity in arid and semi-arid lands of eastern Kenya
(African Crop Science Society, 2022-02-28) D. MUSYIMI; E.O. OUMA; E.O. AUMA; E.J. TOO; L. NGODE; C.K. KAMAU; S. GUDU
Soil moisture deficit is a key constraint to sorghum (Sorghum bicolor) productivity in arid and semi arid lands globally. The objective of this study was to determine the effect of ridging and sorghum bean intercropping (additive system) on soil moisture conservation and sorghum productivity. Sorghum (gadam) was grown either as a sole crop or intercropped with two bean (Phaseolus vulgaris L.) varieties (KATx56 and KAT B1), under two types of ridging (open ridges and tied ridges), and a control without ridges for two years. The study was set up in split plot arrangement, in a randomised complete block design, at the Kenya Agricultural and Livestock Research Organization, Kiboko, in 2019 and 2020. There was no significant interaction between ridging and intercropping. Soil moisture content increased by 11-26% due to ridging; and decreased by -11 and -7% due to sorghum-KAT B1 and Sorghum-KAT X56 intercropping, respectively. Higher moisture content due to ridging was attributed to formation of basin-like structures, which increased water harvesting and infiltration compared to the no ridges where surface run-off was predominant. The highest moisture content was attained on sole bean, followed by sole sorghum and then sorghum/bean intercropping. The decrease in moisture content in intercrops of sorghum/bean relative to their specific sole crops was attributed to higher crop density, which reduced crop spacing, thus triggering competition for available soil moisture. The highest sorghum grain and equivalent yields were obtained in the ridged plots. Intercropping resulted into decrease in sorghum grain yield, but led to increase in sorghum equivalent yield (SEY) and Land Equivalent Ratio (LER). The results show that both ridging and intercropping are suitable for higher water use efficiency and land productivity in ASALs of Kenya.
Effects of mergers on processed milk market in Kenya
(Emerald Insight, 2018-01-01) Nderitu, Patrick Chege; Ndiritu, Simon Wagura
Purpose The purpose of this paper is to determine the effects of the mergers and acquisitions on market prices, consumer welfare and aggregate profit of the merging firms and those of the non-merging firms and, therefore, answer the question on the overall effect of mergers and acquisitions on different performance measures on milk market using data from all the 34 licensed and active milk processors in Kenya. Design/methodology/approach A new model of analysis as developed from the Canadian Competition Policy maker, i.e. The Canadian Competition Policy merger simulation model, was used. Findings The study found that mergers and acquisitions lead to increase in market shares of the merging firms. The study also found that mergers and acquisitions have a significant effect on product price in the processed milk market. From the findings, the study concludes that mergers and acquisition not only lead to an increase in market shares of both merging and non-merging processed milk firms but also create market dominance due to reduction in the number of market players in the industry. Research limitations/implications The study uses the data for the licensed and active milk processors in the industry. The dormant and the non-licensed processors are excluded. Future studies can use the farm-gate prices as opposed to final consumer prices for the processed milk market. Originality/value The study contributes toward providing information on the effect of buyouts on social welfares, prices, market share, profitability and other relevant market equilibrium performance measures in the processed milk market in Kenya.
Effects of social network factors on information acquisition and adoption of improved groundnut varieties: the case of Uganda and Kenya
(Springer Science and Business, 2014) Thuo, Mary; Bell, Alexandra A.; Bravo-Ureta, Boris E.; Lachaud, Miche´e A.; Okello, David K.; Okoko, Evelyn Nasambu; Kidula, Nelson L.; Deom, Carl M.; Puppala, Naveen
Social networks play a significant role in learning and thus in farmers’ adoption of new agricultural technologies. This study examined the effects of social network factors on information acquisition and adoption of new seed varieties among groundnut farmers in Uganda and Kenya. The data were generated through face-to-face interviews from a random sample of 461 farmers, 232 in Uganda and 229 in Kenya. To assess these effects two alternative econometric models were used: a seemingly unrelated bivariate probit (SUBP) model and a recursive bivariate probit (RBP) model. The statistical evaluation of the SUBP shows that information acquisition and adoption decisions are interrelated while tests for the RBP do not support this latter model. Therefore, the analysis is based on the results obtained from the SUBP. These results reveal that social network factors, particularly weak ties with external support (e.g., researchers, extension agents, etc.), partially influence information acquisition, but do not influence adoption. In Uganda, external support, gender, farm size, and geographic location have an impact on information acquisition. In Kenya, external support and geographic location also have an impact on information acquisition. With regard to adoption, gender, household size, and geographic location play the most important roles for Ugandan farmers, while in Kenya information from external sources, education, and farm size affect adoption choice. The study provides insight on the importance of external weak ties in groundnut farming, and a need to understand regional differences along gender lines while developing agricultural strategies. This study further illustrates the importance of farmer participation in applied technology research and the impact of social interactions among farmers and external agents.
Evaluation of the Knowledge and Activities of a Local Community in Mwea Endemic with Schistosomiasis
(IISTE, 2017) Edward, Okonjo; Dorcas, Yole; Dorington, Ogoyi
Evaluation of the Knowledge and Activities of a Local Community in Mwea Endemic with Schistosomiasis
Exposure assessment to staphylococcus enterotoxins in Nile tilapia supplied through semi-regulated and unregulated value chains
(Elsevier Ltd, 2021-01-01) Onjong, Hillary Adawo; Ntuli, Victor; Mwaniki, Mercy; Njage, Patrick Murigu Kamau
The objective of this study was to estimate the risk associated with staphylococcal enterotoxin (SE) exposure from the consumption of Nile tilapia supplied through the semi-regulated and unregulated value chains in Kenya. The fish supply chain was modeled from landing to consumption of unprocessed (fresh) and processed (salted and sun-dried, smoked, filleted) fish. Data related to the prevalence of Staphylococcus aureus in fish, taking into account survey information on handling, storage, processing and consumption of Nile tilapia were collected from recently completed studies in Kenya. Other model inputs were complemented with data from published and unpublished literature. A probabilistic exposure model was developed with Monte Carlo simulation in Excel add-in software using @Risk software. The simulated levels of S. aureus in fish after handling and storage of salted and sun-dried and smoked fish ranged between 4 log CFU/g and 9.01 log CFU/g (maximum population density), while in fillet, levels of S. aureus following growth during display at retail shops was between 3.10 log CFU/g (5% percentile) and 9.01 log CFU/g (95% percentile). Estimated SE dose per-serving in fish supplied after processing was significantly higher (p < 0.05) in the unregulated (ranged between 0.000150 ng (5% percentile) and 30.0 ng (95% percentile)) than semi-regulated chain. The model revealed that the factors with the highest impact on dose of SE per-serving were the time taken to sell the fish at street markets under ambient conditions and refrigerated fish fillets at retail shops followed by cross-contamination from fish handlers most. The model simulated a zero risk of exposure to SEs from fish supplied via the semi-regulated and unregulated value chain if cross-contamination from handlers was eliminated. Therefore, this highlighted the need for good hygiene practices during the handling and storage of fish along the value chain. A significant reduction in the risk of exposure to SE in processed fish was noted when shelf-life was reduced to a maximum of 72 h. Although the model can be used in risk assessments of fish supplied under the same scenarios, the current study revealed data gaps that need to be addressed to improve the risk assessment.
Frontiers | Milk Composition for Admixed Dairy Cattle in Tanzania
(Frontiers Media, 2018-04-24) Cheruiyot, Evans K.; Bett, Rawlynce C.; Amimo, Joshua O.; Mujibi, Fidalis D. N.
It is well established that milk composition is affected by the breed and genotype of a cow. The present study investigated the relationship between the proportion of exotic genes and milk composition in Tanzanian crossbred dairy cows. Milk samples were collected from 209 animals kept under smallholder production systems in Rungwe and Lushoto districts of Tanzania. The milk samples were analyzed for the content of components including fat, protein, casein, lactose, solids-not-fat (SNF), and the total solids (TS) through infrared spectroscopy using Milko-Scan FT1 analyzer (Foss Electric, Denmark). Hair samples for DNA analysis were collected from individual cows and breed composition determined using 150,000 single nucleotide polymorphism (SNP) markers. Cows were grouped into four genetic classes based on the proportion of exotic genes present: 25–49, 50–74, 75–84, and >84%, to mimic a backcross to indigenous zebu breed, F1, F2, and F3 crosses, respectively. The breed types were defined based on international commercial dairy breeds as follows: RG (Norwegian Red X Friesian, Norwegian Red X Guernsey, and Norwegian Red X Jersey crosses); RH (Norwegian Red X Holstein crosses); RZ (Norwegian Red X Zebu and Norwegian Red X N’Dama crosses); and ZR (Zebu X GIR, Zebu X Norwegian Red, and Zebu X Holstein crosses). Results obtained indicate low variation in milk composition traits between genetic groups and breed types. For all the milk traits except milk total protein and casein content, no significant differences (p < 0.05) were observed among genetic groups. Protein content was significantly (p < 0.05) higher for genetic group 75–84% at 3.4 ± 0.08% compared to 3.18 ± 0.07% for genetic group >84%. Casein content was significantly lower for genetic group >84% (2.98 ± 0.05%) compared to 3.18 ± 0.09 and 3.16 ± 0.06% for genetic group 25–49 and 75–84%, respectively (p < 0.05). There was no significant difference (p < 0.05) between breed types with respect to milk composition traits. These results suggest that selection of breed types to be used in smallholder systems need not pay much emphasis on milk quality differences as most admixed animals would have similar milk composition profiles. However, a larger sample size would be required to quantify any meaningful differences between groups.
Functionalization of sweet potato leaf polyphenols by nanostructured composite β-lactoglobulin particles from molecular level complexations: A review
(Food Chemistry, 2022-03-15) Shadrack Isaboke Makori; Tai-Hua Mu; Hong-Nan Sun
Sweet potato leaf polyphenols (SPLPs) have shown potential health benefits in the food and pharmaceutical industries. Nowadays, consumption of SPLPs from animal feeds to foodstuff is becoming a trend worldwide. However, the application of SPLPs is limited by their low bioavailability and stability. β-lactoglobulin (βlg), a highly regarded whey protein, can interact with SPLPs at the molecular level to form reversible or irreversible nanocomplexes (NCs). Consequently, the functional properties and final quality of SPLPs are directly modified. In this review, the composition and structure of SPLPs and βlg, as well as methods of molecular complexation and mechanisms of formation of SPLPsβlgNCs, are revisited. The modified functionalities of SPLPsβlgNCs, especially protein conformational structures, antioxidant activity, solubility, thermal stability, emulsifying, and gelling properties including allergenic potential, digestibility, and practical applications are discussed for SPLPs future development.
Growth Performance, Metabolic Efficiency and Nutrient Utilization of BALB/C Mice Fed with Diet Made from Leftovers from Cocos nucifera Pulp
(Science Publishing Group, 2019) Ouma, Omondi Gilbert; Bonface, Malala Joel; Baya, Msanzu Joseph; Omukhango, Anjili Christopher; Kamau, Gicharu Gibson; Mae, Huxley Makonde; Mwagandi, Chimbevo Lenny
Shortage of animal feeds as a result of increased demand and competition for scarcely available animal feeds has led to drastic decrease in animal production globally. In Kenya, utilization of various plant parts including leaves, fruits and bark of various plantations is taking center stage. Coconut palm (Cocos nucifera) a member of the pulp family Arecaceae has potential to feed animals from its leftovers after utilization for human food. The study sought to analyze proximate nutritional value composition of Coconut pulp leftovers and its formulated diet as well as in vivo growth performance of BALB/c mice. Formulated coconut pulp leftovers were dried before both phytochemical analysis and in vivo growth performance was determined. The Proximate analysis indicated Coconut pulp leftovers contained; 3.50±0.22% crude protein, 34.15±2.48% dry matter, 65.85±3.97% moisture content, 10.50±1.2422% total sugars and 25.00±0.35% total fats. Analysis of formulated coconut pulp diet indicated elevated crude protein 14.23±0.52%, dry matter 35.97±0.52% and total sugars 20.47±4.26% while moisture content 64.10±0.50% and total fats 22.10±0.50% declined. In vivo results for the Coconut pulp leftovers application on mice model to ascertain growth performance were as follows; weight gain 0.80±0.50%, SGR 0.33±0.29%, FCR 241.67±556.67% and conditional factor 0.47±0.12%. For formulated diet it was weight gain 3.90±3.22%, SGR 1.0483±0.91%, FCR 28.23±28.92% and conditional factor 0.58±0.04%. The result indicates Coconut pulp leftovers have potential for animal feeds diet formulation.

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