NRU :: Browsing by Author "Ongeng, Duncan"

Browsing by Author "Ongeng, Duncan"

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Addition of Orange-Fleshed Sweet Potato and Iron-Rich Beans Improves Sensory, Nutritional and Physical Properties But Reduces Microbial Shelf Life of Cassava-Based Pancake (Kabalagala) Designed for Children 2-5 Years Old
(Journal of Culinary Science & Technology, 2021) Adoko, Melas Cayrol; Olum, Solomon; Elolu, Samuel; Ongeng, Duncan
Innovative use of locally available food resources to develop products of enhanced nutritional quality is one of the strategies believed to alleviate deficiencies of essential micronutrients such as vitamin A and iron that are endemic among children 2–5 years in developing countries such as Uganda. New cassava-based pancake (kabalagala) formulae composed of orange-fleshed sweet potato, iron-rich beans, cassava and sweet banana were developed to target vitamin A and iron needs of children 2–5 years in Uganda. The new products had better sensory appeal and nutrient density, had better physical properties during storage, were stable to oxidative rancidity but had lower microbial shelf-life compared to the original pancake formula (composed of cassava and sweet banana). Notwithstanding bioavailability constraints, theoretical nutritional computation revealed that serving 100 g (approximately four pieces) of the new products would contribute approximately 99–102% of vitamin A and 110–119% of iron requirements of the targeted children.
Agronomic Biofortification from a Stakeholder’s Viewpoint Evidence from Studies on Iodine-Enriched Foods in Uganda
(Vitamins and minerals biofortification of edible plants, 2020) Olum, Solomon; Wesana, Joshua; Odongo, Walter; Mogendi, Joseph; Okello, Collins; Webale, Dominic; Ongeng, Duncan
This chapter provides an overview of two case studies that examine stakeholder reactions toward iodine biofortification in Uganda. The first case applies the protection motivation theory and evaluates the intention of school heads and parents of school-aged children to include iodine-biofortified legumes in school feeding programs. The second case study takes a broader scope of stakeholder groups and applies the analytical hierarchy process, a multicriteria decision-making tool, to understand the stakeholders' evaluation of the relative importance of Strengths, Weaknesses, Opportunities, and Threats (SWOT) factors in implementing agronomic iodine biofortification in Uganda. Results from the two cases demonstrate that stakeholders are generally optimistic about the iodine biofortification strategy to improve iodine intake and address the prevalent iodine deficiency disorders. Both cases provide insights into key factors that need to be considered in implementing iodine biofortification technology in a developing country.
Agronomic Biofortification from a Stakeholder’s Viewpoint Evidence from Studies on Iodine-Enriched Foods in Uganda
(Vitamins and minerals biofortification of edible plants, 2020) Olum, Solomon; Wesana, Joshua; Odongo, Walter; Mogendi, Joseph; Okello, Collins; Webale, Dominic; Makokha, Anselimo; Ongeng, Duncan; Gellynck, Xavier; Steur, Hans De
This chapter provides an overview of two case studies that examine stakeholder reactions toward iodine biofortification in Uganda. The first case applies the protection motivation theory and evaluates the intention of school heads and parents of school-aged children to include iodine-biofortified legumes in school feeding programs. The second case study takes a broader scope of stakeholder groups and applies the analytical hierarchy process, a multicriteria decision-making tool, to understand the stakeholders' evaluation of the relative importance of Strengths, Weaknesses, Opportunities, and Threats (SWOT) factors in implementing agronomic iodine biofortification in Uganda. Results from the two cases demonstrate that stakeholders are generally optimistic about the iodine biofortification strategy to improve iodine intake and address the prevalent iodine deficiency disorders. Both cases provide insights into key factors that need to be considered in implementing iodine biofortification technology in a developing country.
Bacteriophage P22 to Challenge Salmonella in Foods
(International Journal of Food Microbiology, 2014) Zinno, Paola; Devirgiliis, Chiara; Ercolini, Danilo; Ongeng, Duncan; Mauriell, Gianluigi
In this study we considered the influence of phage addition on the fate of Salmonella enterica serovar Typhimurium in different foods. Phage P22 was applied to the following: liquid eggs, energy drinks, whole and skimmed milk, apple juice, chicken breast and chicken mince all spiked with its host, whose growth was monitored for 24 and 48 h at 4 °C. Appreciable host inactivation, generally in the order of 2 log cycles, was achieved compared to phage-free controls in all food matrices when 104 UFC/g host inoculum was used. Furthermore, wild food strains belonging to the serotypes Typhimurium, Enteritidis, Derby Give, Newport, Muenchen and Muenster were assayed towards phage P22. Only isolates of Salmonella Typhimurium as well as Salmonella Derby and Salmonella Enteritidis was inhibited by the presence of P22 phage. Additional challenge experiments were carried out by spiking liquid-eggs, chicken breast and chicken mince with mixes of wild Salmonella Typhimurium (at concentration of about 104 UFC/g) strains along with their relative phage P22. The results showed a reduction of 2–3 log cycles after 48 h at 4 °C depending on both mix of strains and the specific food. Overall, the results indicate that phages may be useful in the control of food-borne pathogens. The food matrices considered, the liquid more than the solid, do not seem to affect the phage ability of infection compared to similar tests performed in vitro.
Brucellosis: Community, Medical and Veterinary Workers’ Knowledge, Attitudes, and Practices in Northern Uganda
(Int J One Health, 2017) Nabirye, Harriet Muloki; Erume, Joseph; Nasinyama, George William; Kungu, Joseph Morison; Nakavuma, Jesca; Ongeng, Duncan; Owiny, David Okello
This study aimed at determining the knowledge, attitudes, and practices of the community, medical and veterinary workers regarding brucellosis.A cross-sectional study was conducted at selected health facilities in Apac, Gulu, Lira, and Pader districts of Northern Uganda using a standardized questionnaire. A total of 251 patients testing positive for brucellosis using the Brucella plate agglutination test, 59 medical and 29 veterinary workers were studied. Chi-square test at 95% confidence level was used to analyze data.Only 8% patients, 15.3% medical, and 21.4% veterinary workers were knowledgeable on transmission methods and symptoms for brucellosis and knowledge differed according to the level of education among patients (p=0.001), medical (p=0.001), and veterinary workers (p=0.012). Over 80% patients, medical and veterinary workers had a positive attitude. Only 8% patients, 13.6% medical, and 7.1% veterinary workers had good practices regarding brucellosis control. Poor knowledge, poor practices, and positive attitude provide an opportunity for health education and policy formulation for the control of brucellosis. The prevalence studies of human and animal brucellosis are recommended to determine the magnitude of the problem.
Consumers Fear for Novel Food Processing Technologies: An Application of Food Technology Neophobia Scale in the Consumption of Processed Milk Products in Northern Uganda
(Applied Food Research, 2022) Okello, Robine; Odongo, Walter; Ongeng, Duncan
New food processing technologies are continuously being introduced in the food industry due to the potential benefits such as longer product shelf life, convenience, sensory appeal, and nutritional superiority. Despite their potential benefits, consumers' perceptions and attitudes towards food processing technologies remain a complex phenomenon as consumers tend to take a more conservative stance concerning novel food processing technologies. This paper applied the Food Technology Neophobia Scale(FTNS) to assess the influence of food technology neophobia, and socio-economic factors on the consumption of processed milk products. Data was collected from 400 milk consumers in northern Uganda using structured questionnaires. Analysis was done in SPSS version 21, and binary logistic regression. Results show that milk consumers in northern Uganda are characterized by a high degree of food technology neophobia towards processed milk products (FTNS score of 62). Education(p=0.04), income(p=0.08), risk perception(p=0.00), healthy choice(p=0.06) and media role (p=0.00) were the major factors that influenced the consumption of processed milk products. The paper concludes that Food technology neophobia, food culture and tradition are the most important factors in the success of foods produced by novel technologies.
Contextual Determinants of Learning Behaviour Differentials amongst Host-farmers of University-Student Outreach in Uganda
(Advances in Agricultural Science, 2019) Kalule, Stephen W.; Sseguya, Haroon; Ongeng, Duncan; Karubanga, Gabriel A.
In Sub-Saharan Africa, a knowledge void still exists on two contextual questions of university-community outreach: 1) how social demographics differences are related to farmer learning behaviour towards student outreach, and 2) how student outreach models compare with public and non-public extension services. A cross-section survey was used to obtain data from a sample of 283 respondents purposively selected from previous hosts of student outreach of Gulu University in Uganda. Results from Kruskal-Wallis method revealed that there were significant differences among host-farmers with respect to farmstead distance to the university for knowledge sharing (?2 (2) = 8.5; P < 0.05) and giving feedback (?2 (2) = 7.6; P < 0.05). Regarding the experience of participating in outreach program, significant differences among host-farmers were found in seeking information (?2 (2) = 12.3; P < 0.01); knowledge sharing (?2 (2) = 10.4; P < 0.01); seeking feedback (?2 (2) = 16.4; P < 0.01) and giving feedback (?2 (2) = 8.1; P < 0.05). Further, Friedman test results showed that host-farmers perceived the university-student outreach to be superior and significantly different from public and non-public agricultural extension. We conclude that university outreach is a useful service to farmer. However, its success in facilitating farmer learning is dependent on farmstead distance to the university and farmers’ level of experience of participating in university activities. We recommend more logistical support from governments to university outreach programs so that outreach services can efficiently complement public and non-public interventions in delivering community-based training and learning approaches.
Development and Validation of a Culture-Based Method Suitable for Monitoring Environmental Survival of Escherichia Coli O157:H7 and Salmonella Enterica Serovar Typhimurium in Developing Countries
(Annals of microbiology, 2011) Ongeng, Duncan; Muyanja, Charles; Ryckeboer, Jaak; Geeraerd, Annemie Helena; Springael, Dirk
A non-GMO culture-based method suitable for studying the fate of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in an agricultural environment in developing countries was developed and validated. This method is based on the use of spontaneous rifampicin-resistant mutants of non-toxigenic variants of E. coli O157:H7 and S. Typhimurium combined with counting of colony-forming units (CFU) on selective media, i.e., Cefixime–Tellurite–Sorbitol MacConkey agar containing 100 μg/ml rifampicin, 50 μg/ml cycloheximide and 50 μg/ml nystatin for E. coli O157:H7 and Xylose–Lysine–Tergitol-4 agar containing the same antimicrobials for S. Typhimurium. Validation experiments using gfp- and ds-red-labelled derivatives of the rifampicin-resistant mutants in a non-sterile manure-soil matrix demonstrated that the new culture method was effective in the selection and recovery of the test strains without any detectable interference from background contaminants both in the short and long term. The rifampicin-resistant-based culture method designed provides a feasible low-cost option to study environmental survival of E. coli O157:H7 and Salmonella spp. in developing countries.
Dietary Intake and Socio-economic Predictors of Inadequate Energy and Nutrient Intake Among Women of Child Bearing Age in Karamoja Sub-region of Uganda
(Research Square, 2021) Muggaga, Christopher; Uma, Ipolto Okello; Kaaya, Archileo Natigo; Taylor, David; Ongeng, Duncan; Mugonola, Basil
Karamoja sub-region is the most food insecure part of Eastern Africa. The poor status of food security in the sub-region is reflected in the high rate of undernutrition among women of child bearing age (WCBA) and children under five years (CUFY). The sub-region is unique in Uganda in terms of cultural diversity, agro-ecology and rainfall pattern, and agricultural practices. However, the influence of these unique characteristics on dietary intake of WCBA in the sub-region is less understood. Therefore, this study examined dietary intake and socio-economic predictors of inadequate energy and nutrient intake among WCBA in Karamoja sub-region. A longitudinal study design was used involving 755 WCBA in the harvesting season where 635 were followed-up in the planting season. Data were collected using 24-hour recall, dietary diversity, and socio-economic and demographic questionnaires. Intake of energy and nutrients were generally significantly higher (p<0.05) during the planting season than in the harvesting season. Irrespective of the district, physiological status and season, household consumption of plant-based foods was far higher than intake of animal-based foods dominated by starchy stables (76-100%), dark green leafy vegetables (70-100%) and legumes, nuts and seeds (22-97%) depending on the district. Majority of the respondents had two meals (breakfast: 65-100%; supper: 90-100%) with up to 45% of WCBA who consumed alcohol across meal times. Overall on average, 57.7, 66.6, 78.5, 60.3, 67.7 and 93.7% of WCBA did not meet the Recommended Daily Allowance (RDA) for energy, protein, calcium, iron, zinc and folic acid, respectively. Binary logistic regression revealed that inadequate intake of energy and nutrients significantly increased (p<0.05) with the status of being Lactating/breastfeeding, and was influenced by age of WCBA, number of women married, education level and occupation of the household head depending on season. This study demonstrated that dietary intake of WCBA in Karamoja sub-region was inadequate. Age of WCBA, number of women married, education level and occupation of the household head and spouse, and being a lactating/breastfeeding mother were the key socio-economic and demographic factors that influenced inadequate intake of energy and nutrients among WCBA.
Disparity in Prevalence and Predictors of Undernutrition in Children under Five Among Agricultural, Pastoral, and Agro-Pastoral Ecological Zones of Karamoja Sub-Region, Uganda: A Cross Sectional Study
(BMC pediatrics, 2022) Okidi, Lawrence; Ongeng, Duncan; Muliro, Patrick Simiyu; Matofar, Joseph Wafula
Undernutrition accounts for nearly half of under-five child mortality in developing countries where household nutrition is largely dependent on agriculture. Despite the strong influence of agroecology on agriculture in those countries, limited information exists on whether undernutrition in children under five varies with agro-ecological location. Using Karamoja sub-region of Uganda, one of the most food insecure parts of Eastern Africa as a case area, and applying a multi-stage sampling procedure, and a structured questionnaire, this study examined in a comparative manner, the prevalence and predictors of undernutrition in children under five among the agricultural, pastoral, and agro-pastoral ecological zones. Chi-square test and Kruskal-Wallis test were used to establish the disparity in prevalence of undernutrition and household contextual characteristics, respectively. Binary logistic regression was used to determine the predictors of undernutrition in children under five among the three agro-ecological zones. The level of statistical significance was set at p ≤ 0.05. The prevalence of underweight, stunting, and wasting ranged from 36 to 58% but varied with agroecology in terms of the peak age ranging from 6 to 37 months. Child characteristics, feeding practices, household economic factors, sanitation factors, and caregiver characteristics that predict undernutrition among children under five were identified (p ≤ 0.05). Caregiver handwashing after using latrine (p = 0.005) and diarrhoea in a fortnight (p < 0.001) increased the likelihood of stunting in pastoral agroecology only whereas cereal storage in both sacks and granary in agro-pastoral zone was associated with reduced likelihood of both underweight (p < 0.001 and p = 0.014) and stunting (p = 0.011 and p = 0.018), respectively. A male child was more likely to be underweight and stunted in pastoral (p = 0.002 and p = 0.011) and agro-pastoral (p = 0.017 and p = 0.002) agroecology, respectively. Household expenses reduced the likelihood of both underweight and wasting in pastoral (p = 0.013 and p = 0.005) and agricultural (p = 0.011 and p = 0.021) agroecology, respectively. Flour storage duration increased the stunting likelihood in pastoral (p = 0.032) and agro-pastoral (p = 0.006) agroecologies. This study has revealed that, in a food insecure developing country setting such as Karamoja sub-region of Uganda, undernutrition among children under five varies with agroecology. Thus, nutritional interventions in such locations should be agroecology specific.
Economic Feasibility of Iodine Agronomic Biofortification: A Projective Analysis with Ugandan Vegetable Farmers
(Sustainability, 2021) Olum, Solomon; Gellynck, Xavier; Wesana, Joshua; Odongo, Walter; Aparo, Nathaline Onek; Aloka, Bonny; Ongeng, Duncan; Steur, Hans De
Cost–benefit analysis of (iodine) biofortification at farm level is limited in the literature. This study aimed to analyze the economic feasibility of applying iodine-rich fertilizers (agronomic biofortification) to cabbage and cowpea in Northern Uganda. Data on costs and revenues were obtained from a survey of 100 farmers, and benefits that would accrue from using iodine fertilizers were elicited using consumers’ willingness to pay (WTP) for the iodine-biofortified vegetables. The cost–benefit analysis demonstrated iodine agronomic biofortification as a highly profitable effort, generating average benefit–cost ratios (BCRs) of 3.13 and 5.69 for cabbage and cowpea production, respectively, higher than the conventional production practice. However, the projective analysis showed substantive variations of economic gains from iodine biofortification among farmers, possibly due to differences in farming practices and managerial capabilities. For instance, only 74% of cabbage farmers would produce at a BCR above 1 if they were to apply iodine fertilizer. Furthermore, a sensitivity analysis to estimate the effect of subsidizing the cost of iodine fertilizer showed that a higher proportion of farmers would benefit from iodine biofortification. Therefore, as biofortification is considered a health policy intervention targeting the poor and vulnerable, farmers could be supported through fertilizer subsidies to lower the production cost of iodine-biofortified foods and to avoid passing on the price burden to vulnerable consumers.
The Effect of Micro-architectural Structure of Cabbage Substratum and or Background Bacterial Flora on the Growth of Listeria Monocytogenes
(International journal of food microbiology, 2007) Ongeng, Duncan; Ryckeboer, Jaak; Vermeulen, An; Devlieghere, Frank
The effect of micro-architectural structure of cabbage (Brassica oleracea var. capitata L.) substratum and or background bacterial flora on the growth of Listeria monocytogenes as a function of incubation temperature was investigated. A cocktail mixture of Pseudomonas fluorescens, Pantoea agglomerans and Lactobacillus plantarum was constituted to a population density of approximately 5 log CFU/ml in order to pseudo-simulate background bacterial flora of fresh-cut cabbage. This mixture was co-inoculated with L. monocytogenes (approximately 3 log CFU/ml) on fresh-cut cabbage or in autoclaved cabbage juice followed by incubation at different temperatures (4–30 °C). Data on growth of L. monocytogenes were fitted to the primary growth model of Baranyi in order to generate the growth kinetic parameters of the pathogen. During storage, microbial ecology was dominated by P. fluorescens and L. plantarum at refrigeration and abuse temperature, respectively. At all temperatures investigated, lag duration (λ, h), maximum specific growth rate (μmax, h− 1) and maximum population density (MPD, log CFU/ml) of L. monocytogenes were only affected by medium micro-architectural structure, except at 4 °C where it had no effect on the μmax of the pathogen. Comparison of observed values of μmax with those obtained from the Pathogen Modelling Program (PMP), showed that PMP overestimated the growth rate of L. monocytogenes on fresh-cut cabbage and in cabbage juice, respectively. Temperature dependency of μmax of L. monocytogenes, according to the models of Ratkowsky and Arrhenius, showed linearity for temperature range of 4–15 °C, discontinuities and linearity again for temperature range of 20–30 °C. The results of this experiment have shown that the constituted background bacterial flora had no effect on the growth of L. monocytogenes and that micro-architectural structure of the vegetable was the primary factor that limited the applicability of PMP model for predicting the growth of L. monocytogenes on fresh-cut cabbage. A major limitation of this study however is that nutrient profile of the autoclaved cabbage juice may be different from that of the raw juice thus compromising realistic comparison of the behaviour of L. monocytogenes as affected by micro-architectural structure.
The Efficacy of Electrolysed Oxidising Water for Inactivating Spoilage Microorganisms in Process Water and on Minimally Processed Vegetables
(International Journal of Food Microbiology, 2006) Ongeng, Duncan; Devlieghere, Frank; Debevere, Johan; Cooseman, Jozef; Ryckeboer, Jaak
The efficacy of Electrolysed Oxidising Water (EOW) for inactivating spoilage microorganisms in process water and on minimally processed vegetables was investigated. The direct effect of EOW on three important spoilage bacteria namely; Pseudomonas fluorescens, Pantoea agglomerans or Rahnella aquatilis was determined by inoculating tap water or “artificial process water” with approximately 8 log CFU/ml pure culture and electrolysing the resultant solutions. The three bacteria were each reduced to undetectable levels at low (0.5 A) and relatively higher levels (1.0 A) of current in tap water and “artificial process water”, respectively. The residual effect of EOW on P. fluorescens, P. agglomerans or R. aquatilis was determined by incubating at room temperature 1 ml (approximately 9 log CFU/ml) pure culture suspensions in 9 ml of EOW-T (EOW produced from tap water), EOW-A (EOW produced from “artificial process water” supplemented with approximately 60.7 mg Cl−/l and 39.3 mg Na+/l) or deionised water (control) for 0, 15, 45 or 90 min. The bactericidal activity of both EOW-T and EOW-A increased with the concentration of free oxidants and incubation period and the three bacteria were completely reduced at free oxidants-incubation period combinations of 3.88 mg/l–45 min and 5.1 mg/l–90 min in EOW-T and EOW-A, respectively. Two types of industrial vegetable process water; salad-mix and soup process water, which had each a total psychrotrophic count of approximately 8 log CFU/ml were then electrolysed. Without any NaCl addition, only 1.2 and 2.1 log reductions of the psychrotrophs in soup and salad-mix process water was attained respectively. Supplementation of the process water with approximately 60.7 mg Cl−/l and 39.3 mg Na+/l afterwards resulted in complete reduction of the psychrotrophic count in both process waters, but soup process water required relatively higher levels of current compared to salad-mix water. Finally, fresh-cut lettuce was washed in EOW-T containing 3.62 mg free oxidants/l, EOW-IP (EOW produced from industrial process water) containing 2.8 mg free oxidants/l or tap water (control) for 1 or 5 min. Washing the vegetables for 1 min in EOW-T resulted in 1.9, 1.2, and 1.3 log reductions of psychrotrophs, lactic acid bacteria and Enterobacteriacae, respectively, which increased to 3.3, 2.6, and 1.9 log reductions after washing for 5 min instead. EOW-IP tested in this work had no bactericidal effect on the microflora of fresh-cut lettuce. Electrolysis could therefore be used to decontaminate process water for vegetable pre-washing and to sanitise tap water for final rinsing of vegetables, respectively.
Facilitating Conditions for Farmer Learning Behaviour in the Student-to-Farmer University Outreach
(The journal of agricultural education and extension, 2019) Kalule, Stephen W.; Sseguya, Haroon; Ongeng, Duncan; Karubanga, Gabriel
This study elucidates on how faculty supervision support to students during farm placements and other facilitating conditions influence farmer learning in the student-centred university outreach. Cross-sectional data were collected from a sample of 283 farmers who had previously hosted students of Gulu University in the student-to-farmer university outreach. Structural equation modelling was used to analyse how faculty supervision support to students in combination with other facilitating conditions affect the formation of intentions for learning and actual farmer learning behaviour. Faculty supervision support in the student-to-farmer outreach was found to significantly influence formation of intentions for learning (β = 0.380; t = 5.263; P < .01) and actual farmer learning behaviour (β = 0.182; t = 2.081; P < .05). Faculty supervision support to students is critical to fostering lasting learning relationships in university outreach. Thus, it needs to be a part of the transformation agenda of the higher education sector for improved community linkages and innovation. Empirical data obtained from the context of student-centred university outreach is used to extend the model of facilitating conditions. The study addresses how faculty supervision support together with farmers’ perception of student attitudes and the value of the learning content influence farmers’ learning behaviour during university outreach.
Farmers’ Adoption of Agricultural Innovations: A Systematic Review on Willingness to Pay Studies
(Outlook on Agriculture, 2020) Olum, Solomon; Gellynck, Xavier; Juvinal, Joel; Ongeng, Duncan; Steur, Hans De
Unlike most studies that focused on specific innovations, this study systematically analyzed farmers’ adoption of agricultural innovations in general. It reports willingness to pay (WTP; willingness to accept (WTA)) as a proxy for adoption, its determinants, applied methods, and statistical models. After searching and screening, 80 studies qualified for review. Majority (n = 30) of studies focused on farmers’ WTP for innovations in agricultural water provision or environmental and crop protection (n = 35), while the remaining studies handled crop or animal improvement innovations. Most studies were performed in developing countries, using stated preference methods for economic valuation, with 55% of the studies (n = 44) applying contingent valuation compared to 39% taking choice modeling approach. While farmers are generally willing to pay premium for improvement in agriculture technologies, WTP (WTA) depends on the innovation (system). For example, premiums ranged from about 0.125 to 2 USD/m3 of water depending on water supply (e.g. ground vs. surface water). Furthermore, the determinants of farmers’ WTP can be grouped into sociodemographic, biophysical, technological, institutional, and behavioral factors. As illustrated by relatively high WTP, the review demonstrates that farmers embrace most innovations, regardless of the context and methods applied.
Fate of Escherichia Coli O157:H7 and Salmonella Enterica in the Manure-Amended Soil-Plant Ecosystem of Fresh Vegetable Crops: A Review
(Critical reviews in microbiology, 2015) Ongeng, Duncan; Geeraerd, Annemie Hellena; Springael, Dirk; Ryckeboer, Jaak; Muyanja, Charles; Mauriello, Gianluigi
Enterohemorrhagic Escherichia coli (EHEC) and Salmonella enterica have been implicated in several disease outbreaks linked to consumption of fresh vegetables. Both ruminant and non-ruminant animals carry EHEC and S. enterica in their gastrointestinal tracts and can shed the pathogens in the faecal matter both in symptomatic and asymptomatic states. Application of animal waste in soil fertility management and irrigation of crops with contaminated waste water has been recognised as an important route through which EHEC and S. enterica can contaminate fresh vegetables during primary production. The behavior of E. coli O157:H7 and S. enterica in the agricultural environment has been extensively studied in the last decades. Several microbiological detection methods have been applied. This review therefore puts together current knowledge on the behavior of E. coli O157:H7 and S. enterica in the manure-amended soil-plant ecosystem of fresh vegetable crops during cultivation under various environmental conditions. The review focuses on methodological issues involved in undertaking survival studies and makes comparative analysis of experimental results obtained from studies conducted under controlled environmental conditions integrating results obtained from field experiments. Finally, a theoretical discussion on the potential likely impact of climate change on pre-harvest safety of field-cultivated vegetables is highlighted.
In Vitro Bioavailability-Based Assessment of the Contribution of Wild Fruits and Vegetables to Household Dietary Iron Requirements Among Rural Households in a Developing Country Setting: The Case of Acholi Subregion of Uganda
(Food Science & Nutrition, 2021) Tuyizere, Jean Damascene; Okidi, Lawrence; Elolu, Samuel; Ongeng, Duncan
Wild fruits and vegetables (WFV) are believed to contain substantial quantities of micronutrients and are commonly consumed in rural areas of developing countries endowed with natural vegetation. Previous studies that provided evidence on the contribution of WFV to household micronutrient intake in a developing country setting did not consider the effect of antinutritional factors. Therefore, applying the in vitro bioavailability assessment technique and using the Acholi subregion of Uganda a case area, this study examined the contribution of commonly consumed WFV to the pooled annual household dietary requirement for iron. Laboratory analysis showed that the concentration of antinutrients varied with plant species but the pool was dominated by phytate (10.5–150 mg/100 g) and phenolic substances (38.6–41.7 mg GAE/g). In vitro iron bioavailability varied with plant species was quantitatively higher from vegetables than fruits by 27% although total concentration of the micronutrient was higher in fruits than vegetables by 142%. Nutritional computation, taking into account, household composition, and physiological status revealed that consumption of WFV resulted in a median contribution of 1.8% (a minimum of 0.02 and a maximum of 34.7%) to the pooled annual household dietary iron requirements on the basis of bioavailable iron fraction. These results demonstrate that WFV contributes meagerly to household iron needs but may serve other dietary and non-nutrient health purposes.
Iodine Agronomic Biofortification of Cabbage (Brassica oleracea var. capitata) and Cowpea (Vigna unguiculata L.) Is Effective under Farmer Field Conditions
(Agronomy, 2019) Ojok, Joe; Omara, Peter; Opolot, Emmanuel; Odongo, Walter; Olum, Solomon; Gijs, Du Laing; Gellynck, Xavier; Steur, Hans De; Ongeng, Duncan
Iodine (I) is an essential micronutrient, which plays a critical role in human metabolism. However, its concentration is known to be low in most soils, making it deficient in crops. With most I agronomic biofortification studies conducted under controlled environments, limited information currently exists on this approach of enriching I deficient crops under farmer field conditions. Two-year field experiments were conducted in 2017 and 2018 to examine efficacy of cowpea and cabbage in the uptake of foliar applied potassium iodide (KI) and potassium iodate (KIO3), each with 0, 5, 10, and 15 kg I ha−1 under farmer field conditions. Results indicate that KI was 34% more efficient than KIO3. Iodine concentration increased with application rate. In cabbage, the lowest I concentration (8.2 mg kg−1) was registered at 5 kg I ha−1 with KIO3 while the highest was 109.1 mg kg−1 at 15 kg I ha−1 with KI. Cowpea registered the lowest I concentration of 531.5 mg kg−1 at 5 kg I ha−1 with KIO3 while the highest (5854.2 mg kg−1) was registered at 15 kg I ha−1 with KI. Therefore, cowpea and cabbage can be effectively biofortified through foliar application of both KI and KIO3 under farmer field conditions.
Microencapsulation by Vibrating Technology of the Probiotic Strain Lactobacillus Reuteri DSM 17938 to Enhance its Survival in Foods and in Gastrointestinal Environment
(LWT-Food Science and Technology, 2015) Prisco, Annachiara De; Maresca, Diamante; Ongeng, Duncan; Mauriello, Gianluigi
The probiotic strain Lactobacillus reuteri DSM 17938 was microencapsulated in alginate (MC) and in chitosan-alginate (CMC) matrix by vibrating technology with the main purpose to improve its tolerance to adverse environments. Microencapsulation procedure proved to not affect cell viability as indicated by a high encapsulation yield (97%) as well as further chitosan coating that minimally affected cell population. The viability of microencapsulated probiotic was evaluated under several stress conditions such as 28 days storage in different solutions at 4 and 20 °C, simulated gastrointestinal passage and osmotic stress conditions. Also reuterin production and diffusion through microcapsules were assessed. Results of survival assays showed that in most of tested conditions microencapsulation significantly (P < 0.05) improved L. reuteri DSM 17938 resistance. Furthermore, microcapsules were freeze dried in skimmed milk and no significant variations in cell viability and microcapsules morphology were observed. Morphological analysis revealed some differences between MC and CMC although both microcapsules had a diameter of 110 ± 5 μm, a spherical shape and a uniform and continuous surface. This study proved that microencapsulation by n chitosan-alginate matrix could improve tolerance of L. reuteri DSM 17938 towards stress conditions encountered in food processing as well as preserve its functional properties.
The Mix of Good Nutritional Attitude and Poor Nutritional Knowledge is Associated with Adequate Intake of Vitamin A and Iron from Wild Fruits and Vegetables among Rural Households in Acholi Subregion of Northern Uganda
(Food Science & Nutrition, 2018) Okidi, Lawrence; Odongo, Walter; Ongeng, Duncan
Nutritional knowledge and attitude of a population greatly affect intake of essential micronutrients. Much of the understanding on the impact of nutritional knowledge and attitude on nutrient intake has been derived from studies conducted among affluent societies using commercial food products. However, information on the link between status of nutritional knowledge and attitude on intake of essential nutrients from wild fruits and vegetables among rural communities is largely lacking. This study examined the status of nutritional knowledge and attitude associated with intake of vitamin A and iron from wild fruits and vegetables among rural households in Acholi subregion of northern Uganda. A cross-sectional study design making use of individual household questionnaire and proximate dietary recall of a calendar year consumption period involving 248 randomly selected rural households was applied. Results showed that households had good nutritional attitude but poor nutritional knowledge. Status of knowledge was dependent on nutrition training (p = 0.028; coefficient, β = 0.710) and age of the respondent (p = 0.044; β = −0.023), whereas status of attitude was predicted by age of the respondent (p = 0.014; β = 0.048). Consumption of wild fruits and vegetables contributed adequately to the dietary vitamin A and iron requirements of the households. The results have demonstrated that intake of vitamin A and iron from wild fruits and vegetables among rural households is associated with good nutritional attitude but poor nutritional knowledge. A concerted effort is necessary to improve household nutritional knowledge for better utilization of wild fruits and vegetables.

Browsing by Author "Ongeng, Duncan"

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