In spite of the documented success of Pathogen Reduction and Hazard Analysis and Critical Control Points (PR/HACCP) at the processing level, farm-level and retail-level application is optional. Several factors impact the gap of food safety regulations from farm to fork. This thesis focuses on the retail level. At the retail level, pathogen survival and the associated ability to cause further disease to humans even after being subjected to certain processing and packaging conditions have varying implications on the probability of sickness or death. This issue also arises over the fact that, sometimes, appropriate handling and processing instructions are not properly followed by consumers. The primary goals of the project are to develop an optimal food safety intervention strategy that incorporates risk, cost, and the value of pathogen reduction with alternative control mechanism. We wish to evaluate incentives for PR/HACCP-like planning and adherence to best management practices that promote safe food production. These incentives will be evaluated for the retail level. In addition, we will develop optimal intervention strategies for ready-to-eat meats and poultry products that incorporate risk assessment, cost of intervention, and the value of risk reduction of alternative strategies for the farm-to-table continuum. The model adopted in this study is an expansion of the stochastic optimization model developed by Nganje, Kaitibie, and Sorin (2005) to include the optimal intervention strategy at the retail ( consumer) level. These components are simulated with firm-level microbial data at the processing and retail level using stochastic optimizer software. Stochastic dominance was also used to compare across the optimal strategies and determine if there is one clear choice that is preferred. This allowed us incorporate risk preferences of firms. The scenario method was used to determine what factors would likely affect the adoption of PR/HACCP at the retail level. Finally, this thesis provides firms and policymakers a direction for future options concerning risk mitigation strategies.

Qualità e sicurezza degli alimenti, inclusa la loro tracciabilità ed autenticità, è diventato ngli ultimi anni obiettivo primario per la salute e il benessere dei consumatori. Il progetto è diretto allo sviluppo e applicazione di metodiche DNA-based per la tracciabilità di specie vegetali, varietà di frumento duro e microorganismi a difesa della qualita’, salubrita’ ed autenticità della filiera grano e prodotti processati. Le attività progettuali dello studio sono finanziate da industria (Barilla S.P.A.) con il coinvolgimento di enti pubblici di ricerca (Università Cattolica Del Sacro Cuore Di Piacenza, CREA-GB di Fiorenzuola D’arda). Il progetto si articola in tre argomenti principali: WP1.Tracciabilità di specie vegetali nella filiera pasta. Tracciabilità di varietà di frumento duro nella filiera pasta A questo scopo sono state intraprese nel secondo anno di attività due azioni dirette allo sviluppo e validazione di due diverse metodiche di fingerprinting varietale. Partendo dalle direttive UPOV in materia di impiego di marcatori molecolari per la caratterizzazione varietale è stata applicata e validata su di un pool di 26 varietà di interesse per l’industria un’ analisi basata su di una combinazione di marcatori SSR (Simple Sequence Repeats) che ha consentito di identificare in maniera univoca ciascuna delle varietà in esame. Il saggio è stato trasferito ai laboratori dell’industria che lo applica attualmente nella routine per il controllo di partite di granella. A fronte della robustezza dell’analisi SSR si pongono però i lunghi tempi analitici. Per ottimizzare questo aspetto si è completata un’attività di sequenziamento parziale del genoma di 28 varietà presenti in due repliche biologiche (52 campioni) e 12 mix di DNA di due varietà (4 differenti percentuali per ogni coppia di varietà miscelate). I dati ottenuti hanno fornito circa 15.000 marcatori molecolari DArT-seq (Diversity Array Technology ) e SNP (Simple Nucleotide Polimorphisms). Dall’intero set di marcatori è stato quindi individuato, attraverso una procedura bioinformatica, un set ridotto di marcatori ad alta informatività in grado di identificare univocamente le singole varietà e di predire la presenza di altre varietà in miscela e la percentuale di contaminazione. WP2.Tracciabilità Di Microrganismi Fungini Nella Filiera Pasta Questo studio è volto al controllo e identificazione di specie microbiche patogene che possono svilupparsi lungo la filiera grano con conseguente impatto negativo sulla salubrità di granella, di semole e dei prodotti finiti. A questo scopo sono stati prodotti campioni di granella a contaminazione controllata. Si è costituita attraverso l’analisi delle sequenze Barcode una ceppoteca che comprende i maggiori patogeni fungini che possono contaminare la granella durante la crescita della pianta in campo o durante lo stoccaggio della granella. Dopo l’inoculo artificiale dei singoli ceppi in due varietà di frumento duro, sono stati raccolti, a tempi crescenti, campioni di spighe e granella. La metodica è risultata rapida e sensibile nell’identificazione di DNA fungino fin dalle prime fasi dell’infezione, quando i sintomi della malattia risultavano ancora non ancora visibili. Le informazioni di sequenza Barcoding, in prospettiva, potranno essere utilizzate per sviluppare nuovi metodi di identificazione fungina più sensibili e rapidi. WP3. Identificazione molecolare di microrganismi vivi o morti in pesto L’obiettivo di questo lavoro è stato quello di sviluppare metodiche di V-qPCR (Viability-PCR), per permettere l’identificazione, quantificazione e discriminazione cellule microbiche vive o morte in alimentiprocessati, come il pesto. Per lo studio è stato scelto il batterio patogeno B.cereus, microrganismo ubiquitario, patogeno e sporigeno di difficile identificazione soprattutto in matrici complesse. Durante questo lavoro è stato sviluppato un protocollo analitico che prevede l’estrazione del DNA batterico da pesto, matrice interferente e complessa. Parte del lavoro è stata svolta presso l’Istituto di Microbiologia dell’Università Cattolica e l’Istituto IATA CSIC Institut d’Agroquímica i Tecnologia dels Aliments in Valencia. / Food quality and safety, including food traceability and authenticity, have become crucial in the last decades. Today, molecular and genetic progress can support the agri-food industry, due to the improvement of new analytical tools. Among the available applications, DNA-based methods can detect the presence of a particular species or variety along the food supply chain, verify the genetic identity of food and feed ingredients and detecting the presence of contaminating organisms, thus becoming an essential tool to study patterns, causes, and risk factors of diseases and outbreaks. As a consequence, genetic analysis has become increasingly popular even among non-specialists and highly beneficial for consumers, agricultural farmers, governments, and the private sector (Reid, O’Donnell, and Downey 2006). In this framework, the research developed in this thesis arises by active collaboration between the private company Barilla G. & R. Fratelli S.p.A., the public research institute CREA-GB (Consiglio per la Ricerca in agricoltura e l'analisi dell Economia Agraria) and Università Cattolica del Sacro Cuore, to develop a set of DNA-based methods to improve the traceability and authenticity of plant and microbial species and durum wheat varieties applicable from farm to fork. Following these aims, the research developed in this thesis includes: 1. The optimization and validation of qPCR assay for the discrimination of plant species along the pasta production chain through the organization of a ring test involving nine Italian public and private laboratories. The results obtained in this study were published in the Journal of Cereal Science (Chapter 2); 2. The discrimination of durum wheat varieties by selecting SSRs and DarT molecular markers as reliable methods for variety fingerprinting (Chapter 3). The results confirm the sensitivity of the method and the feasibility to 7 protect the food industry from fraud and ensure the consumer a certified pasta quality; 3. The application of the Barcoding technique and the development of qPCR assay for the identification and quantification of field fungi (Fusarium, Alternaria, Michrodochium, Cochliobolus spp.) and saprophytic fungi (Aspergillus, Penicillium, Rhizopus spp) along the wheat chain (Chapter 3). The sensitivity of the method was investigated by inoculating potted durum wheat plants at full anthesis and wheat kernels (pre and postharvest trials). The DNA-based methods demonstrate a key role in pathogen detection and the application in several points of the wheat chain (e.g., for control of both locally and imported grains, for storage lots, to evaluate the environmental risk associated with grain powder for farmers and workers); 4. The optimization of Viability q-PCR (V-qPCR) for the discrimination of dead and alive Bacillus cereus, a spore-forming bacteria (Chapter 4). The results of PMAxx, combined with qPCR, have demonstrated the selective discrimination of B.cereus viable cells, with no false-positive signals determined by dead cells, a peculiar aspect of thermally treated food; 5. The comparison of two DNA extraction kits (FastDNA® SPIN Kit for Soil – MB and NucleoSpin Tissue - Macherey Nagel) by detecting B.cereus spores in basil pesto sauce, selected as a model food matrix. Despite the limit of detection (LOD) achieved (respectively 1.8x102 spores/gr by using Fast DNA TM SPIN and 2.7 x 105 spores/gr by using NucleoSpin®), the principal challenge remains the spores' DNA extraction from the complex matrix. Lastly, the results obtained during the doctoral research project were globally discussed (Chapter 5).

MPH / Department of Public Health

<p>We followed up with about 2,000 smallholder households in Senegal, two years after these households participated in a randomized controlled trial (RCT) aimed at reducing levels of aflatoxins in smallholders’ stored maize. In the initial intervention, treated households were provided with training on proper post-harvest practices, low-cost moisture meters for testing if maize was sufficiently dry to store, plastic tarps for drying maize of the ground, and hermetic (airtight) storage bags to mitigate aflatoxin development in stored maize. Using cross-sectional follow up data on aflatoxins levels and drying and storage practices from 2019 along with baseline demographic data from 2016, we estimate both the longer-term intention-to-treat (ITT) effects and the treatment on the treated (TOT) effects that the four inputs provided on households’ aflatoxins levels in stored maize. The ITT analyses estimate the intervention’s average effect by treatment group, but this may underestimate the true impact for households who complied with recommended post-harvest practices and adopted the recommended technologies. The TOT analyses estimate the local average treatment effects (LATE) of the intervention, that is its impacts on those who were driven by the intervention to follow best practices or use a given technology. Since the decision to follow these practices or adopt a technology was not random, we instrumented the usage decision with the exogenous, random treatment group assignment to get an unbiased estimate. Outside of our main models, we conducted a heterogeneity analysis to test if households with different characteristics benefit differently from the intervention. We interacted each treatment assignment with various household characteristics, including the woman’s level of involvement in the intervention. Additionally, we estimate the cost-effectiveness of providing training and a tarp, according to WHO guidelines for public health interventions. </p>

Background Food handlers knowledge and related attitude and practices towards food hygiene plays a significant role in reducing food-borne disease, which represents a growing concern for public health interest. Aim To explore the knowledge, attitudes and practices of food hygiene among food handlers in Bangladeshi homes located in urban areas exposed to climate change. Methodology A descriptive cross sectional study was conducted to perform this study. An online questionnaire survey was used as a tool for data collection. Food handlers were selected through convenience sampling method. Data were statistically analyzed using SPSS software version 27. Results In case of food hygiene knowledge, attitudes and practices, study participants had good knowledge (78.77%), moderate attitude (57.4%) and good practice level (88.82%) in food hygiene at home. There is no significant difference between men and women in their knowledge level but had significant difference in their attitude and practice level. Besides, there is no significant difference in food hygiene knowledge of food handlers based on their educational level but results showed significant difference in their attitude and practices of food hygiene. Conclusion Food handlers in Bangladeshi homes were knowledgeable with moderate attitude and good practice level. Continuous food safety education, health education and media campaigns will help them to reduce the risk of diarrhea and food-borne illness.

Text in English / Fungal species and their mycotoxins are the most predorminant contaminants of dried agricultural products in sub-Saharan Africa (SSA) and the main species of fungi that can synthesize mycotoxins are Aspergillus, Fusarium and Penicillium. In Africa, aflatoxin is labelled as a great threat to human and animal health due to its high contamination levels reported of aflatoxins in foods. The aim of this study was to survey fungi and aflatoxin contamination of small-scale processed foodstuffs sold at informal retail outlets in the Johannesburg metropolis, South Africa. A total of 270 food samples (10 starch and legume based foods, 11 meat and fish based foods, 22 spices and local condiments, 14 dried fruits and vegetables) were collected from retailers; and analysed four (4) times in different seasons of spring, summer, autumn and winter. Out of the 270 samples analysed, only 27.8% were contaminated with fungal. Of all the six categories of foods analysed, roots and tubers (60.0%), nuts and seeds (40.0%), dried vegetables (37.1%), and the Meat and Insect foods (33.3%) respectively, had the most contaminated samples with fungal respectively. The least contaminated food groups were the fish foods (10.0%) and spices and local condiments (16.7%) respectively. Twenty percent of the 270 dried food analysed were contaminated by Aspergillus species out of which 61.1% of the contaminated samples had fungal counts above 103 cfu/g. Aspergillus niger was the most predominant Aspergillus species identified in all the categories of food samples analysed. Fruits and vegetables (24.4%) and the nuts and seeds (20.0%) food groups had the highest number of samples contaminated with aflatoxin. Peanut flour and Cardamom had the most incidence of aflatoxin. AFB1, AFB2 & AFG1 were the most prominent aflatoxin types recovered from the food samples. Almost all the food samples in which aflatoxin were identified had aflatoxin values above 10μg/ml. / Life and Consumer Sciences / M.Sc. (Life Science)

Street-vended foods are convenient and cheap meals, but their contamination can lead to foodborne illness. This study aimed to evaluate food safety knowledge of street food vendors in Ulundi and AbaQulusi local municipalities of Zululand District, South Africa and compliance of their street food vending environment to sanitary requirements. A cross sectional survey design was utilised to gather data from 400 street food vendors using interviews. A piloted checklist was used to collect data on the sanitary characteristics from 200 randomly selected street food vending facilities. Most of the street food vendors were black (99%), females (73%), and above 35 years (55%). Only the minority of street food vendors had attended a high school (47%) and the vast majority (77%) of them had not attended any food safety training course. The majority (64.7%) of respondents knew that food should not be handled when they have diarrhoea, even if their hands were washed regularly, neither when they have flu, colds, cough, or catarrh. The minority (43%) of street food vendors knew that the use of separate cutting boards for meat and salad, and washing them between uses are the safest ways to avoid cross-contamination. The majority (79.4%) of street food vendors were aware that microorganisms could cause foodborne diseases that may lead to death. The vast majority (76%) of street food vendors had low food safety knowledge and only 14% of the street food vending sites had high compliance with sanitary conditions. In conclusion, most street food vendors possessed inadequate food safety knowledge in key food safety parameters and most of the street food vending facilities were noncompliant. Furthermore, most of them operate under poor sanitary conditions. Street food vendors should be provided with compliant waste disposal and standard kitchen facilities with water resources to ensure hygienic preparation and serving of food. / Life and Consumer Sciences / M. Cons. Sci.

No description available.

Two studies were conducted to investigate potential factors that affect consumers' perception towards home meal kits, and potential foodborne illness risks factors of home meal kits usage. <div>In study 1, a cross-sectional data collection was performed by using an online, self-administrated questionnaire. The participants who were the adults residing in U.S. were asked to answer the survey using the Likert scales. Multiple linear regression and moderation analyses were conducted to determine the associations between variables. The differences between HMK users and non-users were assessed by an independent t-test.</div><div>In study 2, three studies were developed to investigate the risks factors, including the (1) analysis of the available food safety-related information and delivery protocol collected from the vendors’ websites, (2) examination of the actual commercial HMK shipments, and (3) examination of the temperature changes inside the insulated HMK packages held under the average summer temperatures over time. Potential risk factors retrieved from the three studies were analyzed and the suggested guidelines to control those risks were identified.</div>

La presenten investigación busca determinar el efecto del nivel educativo de los jefes del hogar sobre la seguridad alimentaria de los hogares peruanos. El análisis se realiza a través del modelo Tobit con el fin de evidenciar cuales son los factores y en que cantidad; es decir, busca determinar si el impacto del nivel educativo de los padres es positivo o negativo, junto a otros determinantes dentro del hogar, y cuánta es la probabilidad de ocurrencia de que un hogar cuente con seguridad alimentaria. La investigación concluye que un hogar cuente con seguridad alimentaria, medida como el gasto alimentario del hogar, si los jefes del hogar tienen un nivel educativo más alto junto con mayores ingresos. / This research project aims to determine the effect of the educational level of household heads on the food security of Peruvian households. The analysis is carried out through the TOBIT model in order to show which are the factors and in what quantity. That is, aims to determine whether the impact of the parent’s educational level is positive or negative, together with other determinants within the household has food security. The research concludes that a household has food security, measured as the household’s food expenditure, if the heads of the household have a higher educational level along with higher income. / Trabajo de investigación