Shining light on food microbiology; applications of luciferase-tagged microorganisms in the food industry

Bioluminescence is the production of light by living organisms as a result of a number of enzyme catalysed reactions caused by enzymes termed luciferases. The lux genes responsible for the emission of light can be cloned from one bioluminescent microorganism into one that is not bioluminescent. The light emitted can be monitored and quantified and will provide information on the metabolic activity, quantity and location of cells in a particular environment, in real-time. The primary aim of this thesis was to investigate and identify several food industry related applications of lux-tagged microorganisms. The first aim was to monitor a lux-tagged Cronobacter sakazakii in reconstituted infant milk formula, in realtime. The second aim was to investigate a bioluminescent-based early warning system for starter culture disruption by bacteriophages and antibiotic residues. The third of this thesis was to examine the use of a bioluminescent-based assay to test the activity of bioengineered Nisin derivatives M21V and S29A against foodborne pathogens in laboratory media and selected foods.

Physico-chemical properties and component interactions in high solids food systems

The present study aimed to investigate interactions of components in the high solids systems during storage. The systems included (i) lactose–maltodextrin (MD) with various dextrose equivalents at different mixing ratios, (ii) whey protein isolate (WPI)–oil [olive oil (OO) or sunflower oil (SO)] at 75:25 ratio, and (iii) WPI–oil– {glucose (G)–fructose (F) 1:1 syrup [70% (w/w) total solids]} at a component ratio of 45:15:40. Crystallization of lactose was delayed and increasingly inhibited with increasing MD contents and higher DE values (small molecular size or low molecular weight), although all systems showed similar glass transition temperatures at each aw. The water sorption isotherms of non-crystalline lactose and lactose–MD (0.11 to 0.76 aw) could be derived from the sum of sorbed water contents of individual amorphous components. The GAB equation was fitted to data of all non-crystalline systems. The protein–oil and protein–oil–sugar materials showed maximum protein oxidation and disulfide bonding at 2 weeks of storage at 20 and 40°C. The WPI–OO showed denaturation and preaggregation of proteins during storage at both temperatures. The presence of G–F in WPI–oil increased Tonset and Tpeak of protein aggregation, and oxidative damage of the protein during storage, especially in systems with a higher level of unsaturated fatty acids. Lipid oxidation and glycation products in the systems containing sugar promoted oxidation of proteins, increased changes in protein conformation and aggregation of proteins, and resulted in insolubility of solids or increased hydrophobicity concomitantly with hardening of structure, covalent crosslinking of proteins, and formation of stable polymerized solids, especially after storage at 40°C. We found protein hydration transitions preceding denaturation transitions in all high protein systems and also the glass transition of confined water in protein systems using dynamic mechanical analysis.

Public evaluations of novel food technologies: a qualitative citizen-scientist deliberative discourse approach

This qualitative research expands understanding of how information about a range of Novel Food Technologies (NFTs) is used and assimilated, and the implications of this on the evolution of attitudes and acceptance. This work enhances theoretical and applied understanding of citizens’ evaluative processes around these technologies. The approach applied involved observations of interactive exchanges between citizens and information providers (i.e. food scientists), during which they discussed a specific technology. This flexible, yet structured, approach revealed how individuals construct meaning around information about specific NFTs. A rich dataset of 42 ‘deliberate discourse’ and 42 postdiscourse transcripts was collected. Data analysis encompassed three stages: an initial descriptive account of the complete dataset based on the top-down bottom-up (TDBU) model of attitude formation, followed by inductive and deductive thematic analysis across the selected technology groups. The hybrid thematic analysis undertaken identified a Conceptual Model, which represents a holistic perspective on the influences and associated features directing ‘sense-making’ and ultimate evaluations around the technology clusters. How individuals make sense of these technologies is shaped by: their beliefs, values and personal characteristics; their perceptions of power and control over the application of the technology; and, the assumed relevance of the technology and its applications within different contexts. These influences form the frame for the creation of sense-making around the technologies. Internal negotiations between these influences are evident and evaluations are based on the relative importance of each influence to the individual, which tend to contribute to attitude ambivalence and instability. The findings indicate the processes of forming and changing attitudes towards these technologies are: complex; dependent on characteristics of the individual, technology, application and product; and, impacted by the nature and forms of information provided. Challenges are faced in engaging with the public about these technologies, as levels of knowledge, understanding and interest vary.

Assessing the vulnerability of food crop systems in Africa to climate change

Africa is thought to be the region most vulnerable to the impacts of climate variability and change. Agriculture plays a dominant role in supporting rural livelihoods and economic growth over most of Africa. Three aspects of the vulnerability of food crop systems to climate change in Africa are discussed: the assessment of the sensitivity of crops to variability in climate, the adaptive capacity of farmers, and the role of institutions in adapting to climate change. The magnitude of projected impacts of climate change on food crops in Africa varies widely among different studies. These differences arise from the variety of climate and crop models used, and the different techniques used to match the scale of climate model output to that needed by crop models. Most studies show a negative impact of climate change on crop productivity in Africa. Farmers have proved highly adaptable in the past to short- and long-term variations in climate and in their environment. Key to the ability of farmers to adapt to climate variability and change will be access to relevant knowledge and information. It is important that governments put in place institutional and macro-economic conditions that support and facilitate adaptation and resilience to climate change at local, national and transnational level.

The socioeconomics of food crop production and climate change vulnerability: a global scale quantitative analysis of how grain crops are sensitive to drought

Many studies warn that climate change may undermine global food security. Much work on this topic focuses on modelling crop-weather interactions but these models do not generally account for the ways in which socio-economic factors influence how harvests are affected by weather. To address this gap, this paper uses a quantitative harvest vulnerability index based on annual soil moisture and grain production data as the dependent variables in a Linear Mixed Effects model with national scale socio-economic data as independent variables for the period 1990-2005. Results show that rice, wheat and maize production in middle income countries were especially vulnerable to droughts. By contrast, harvests in countries with higher investments in agriculture (e.g higher amounts of fertilizer use) were less vulnerable to drought. In terms of differences between the world's major grain crops, factors that made rice and wheat crops vulnerable to drought were quite consistent, whilst those of maize crops varied considerably depending on the type of region. This is likely due to the fact that maize is produced under very different conditions worldwide. One recommendation for reducing drought vulnerability risks is coordinated development and adaptation policies, including institutional support that enables farmers to take proactive action.

An introduction to the ‘new’ politics of agriculture and food

The agricultural policy agenda has been broadened with farm policy issues now interlinking with other policy domains (food safety, energy supplies, environmental protection, development aid, etc.). New actors promoting values which sometimes conflict, or which are not always easily reconcilable, with those previously guiding agricultural policy have entered the broader agricultural and food policy domain. The studies of various new policy issues inter-linking with the agricultural policy domain included in this special issue show that value conflicts are addressed in different ways and thus result in inter-institutional coordination and conflict unfolding differently. Studies of inter-institutional policy making in the agricultural policy sector have the potential to contribute to theoretical developments in public policy analysis in much the same way as agricultural policy studies did in the past.

Social innovation in local food in Japan: Choku-bai-jo markets and Teikei cooperative practices

The working paper depicts two innovative examples from Japan of the direct supply of food, which involves the development of closer producer-consumer relations, as well as closer producer-producer networks. Choku-bai-jo and Teikei networks are considered as examples of practices implicated in alternative food networks (AFNs). One example has become a quasi-public endeavour and is seen by the Japanese state as a legitimate part of rural development and is promoted in support of small producers. The other is borne from consumer concern over food quality and, despite its long-lived status, this arrangement remains marginal and with little institutional or governmental support. A model which blends the organization and aims of both examples holds potential for a more sustainable eco-economic future.

Qualifying instrument for evaluation of food and nutritional care in hospital

Establishing criteria for hospital nutrition care ensures that quality care is delivered to patients. The responsibility of the Hospital Food and Nutrition Service (HFNS) is not always well defined, despite efforts to establish guidelines for patient clinical nutrition practice. This study describes the elaboration of an Instrument for Evaluation of Food and Nutritional Care (IEFNC) aimed at directing the actions of the Hospital Food and Nutrition Service. This instrument was qualified by means of a comparative analysis of the categories related to hospital food and nutritional care, published in the literature. Elaboration of the IEFNC comprised the following stages: (a) a survey of databases and documents for selection of the categories to be used in nutrition care evaluation, (b) a study of the institutional procedures for nutrition practice at two Brazilian hospitals, in order to provide a description of the sequence of actions that should be taken by the HFNS as well as other services participating in nutrition care, (c) design of the IEFNC based on the categories published in the literature, adapted to the sequence of actions observed in the routines of the hospitals under study, (d) application of the questionnaire at two different hospitals that was mentioned in the item (b), in order to assess the time spent on its application, the difficulties in phrasing the questions, and the coverage of the instrument, and (e) finalization of the instrument. The IEFNC consists of 50 open and closed questions on two areas of food and nutritional care in hospital: inpatient nutritional care and food service quality. It deals with the characterization and structure of hospitals and their HFNS, the actions concerning the patients' nutritional evaluation and monitoring, the meal production system, and the hospital diets. "This questionnaire is a tool that can be seen as a portrait of the structure and characteristics of the HFNS and its performance in clinical and meal management dietitian activities." (Nutr Hosp. 2012;27:1170-1177) DOI:10.3305/nh.2012.27.4.5868

Work ability among hospital food service professionals: multiple associated variables require comprehensive intervention

The work of hospital food service is characterized by demands that can be associated with work ability - WA. The aim of this study was to evaluate factors associated with WA among hospital food service professionals and recommend intervention measures. This is a cross sectional study carried out in 2009, conducted in a hospital of Sao Paulo, Brazil. Participants were 76 (96.2%) of the eligible. They filled out a questionnaire including socio-demographic data, life styles, working conditions and WA. Multivariate linear regression analyses were performed. Factors associated with WA were age (p=0.051), over commitment (p=0.011), effort-reward ratio (p=0.002) and work injuries (p<0.001). In spite was a young population, age was associated with WA. Association with work injuries is consistent with the theoretical model that demonstrated that health status is the basis to maintain the WA. The association of effort-reward imbalance shows that issues related with work organization are relevant for these workers. The association of overcommittment suggests that workers recognize their responsibility with the therapeutic processes of patients. Results showed a number of features of different nature that should be taken into account when implementing measures to improve the WA, to be applied at different levels: individual, task and institutional.

Carbon sequestration in community forests: trade-offs, multiple outcomes and institutional diversity in the Bolivian Amazon

Carbon sequestration in community forests presents a major challenge for the Reducing Emissions from Deforestation and Forest Degradation (REDD+) programme. This article uses a comparative analysis of the agricultural and forestry practices of indigenous peoples and settlers in the Bolivian Amazon to show how community-level institutions regulate the trade-offs between community livelihoods, forest species diversity, and carbon sequestration. The authors argue that REDD+ implementation in such areas runs the risk of: 1) reinforcing economic inequalities based on previous and potential land use impacts on ecosystems (baseline), depending on the socio-cultural groups targeted; 2) increasing pressure on land used for food production, possibly reducing food security and redirecting labour towards scarce off-farm income opportunities; 3) increasing dependence on external funding and carbon market fluctuations instead of local production strategies; and 4) further incentivising the privatization and commodification of land to avoid transaction costs associated with collective property rights. The article also advises against taking a strictly economic, market-based approach to carbon sequestration, arguing that such an approach could endanger fragile socio-ecological systems. REDD+ schemes should directly support existing efforts towards forest sustainability rather than simply compensating local land users for avoiding deforestation and forest degradation

Innovative Agricultural Approaches of Promoting Food Security in Eritrea: Trends, Challenges and Opportunities for Growth: Proceedings of the Workshop of the Association of Eritreans in Agricultural Sciences (AEAS)

Eritrea is a Sahel country in terms of climate, and rainfall is low and highly variable. Shortage of food is thus a recurrent problem, and food security one of the key issues in development. The present publication presents the results of a nationwide workshop organised in 2006 in Asmara, Eritrea, by the Association of Eritreans in Agricultural Sciences (AEAS). The workshop was attended by over 200 participants from government administration, academia, development circles including NGOs and UN organisations. Specifically, the present publication deals with themes such as biotechnology, non-wood forest products, spate irrigation, the role of women relating to food security, and institutional and organisational aspects of food security. It also contains a chapter with policy recommendations, as well as an extensive summary of the main findings (paper abstracts) in Tigrinya.

Strengthening the food systems governance evidence base: Supporting commensurability of research through a systematic review of methods

Governance of food systems is a poorly understood determinant of food security. Much scholarship on food systems governance is non-empirical, while existing research is often case study-based and theoretically and methodologically incommensurable. This frustrates aggregation of evidence and generalisation. We undertook a systematic review of methods used in food systems governance research with a view to identifying a core set of indicators for future research. We gathered literature through a structured consultation and sampling from recent reviews. Indicators were identified and classified according to the levels and sectors they investigate. We found a concentration of indicators in food production at local to national levels and a sparseness in distribution and consumption. Unsurprisingly, many indicators of institutional structure were found, while agency-related indicators are moderately represented. We call for piloting and validation of these indicators and for methodological development to fill gaps identified. These efforts are expected to support a more consolidated future evidence base and eventual meta-analysis.

The Financialization of Food: An Inquiry into the 2008-2011 Food Price Spikes

This dissertation investigates the question: has financial speculation contributed to global food price volatility since the mid 2000s? I problematize the mainstream academic literature on the 2008-2011 food price spikes as being dominated by neoclassical economic perspectives and offer new conceptual and empirical insights into the relationship between financial speculation and food. Presented in three journal style manuscripts, manuscript one uses circuits of capital to conceptualize the link between financial speculators in the global north and populations in the global south. Manuscript two argues that what makes commodity index speculation (aka ‘index funds’ or index swaps) novel is that it provides institutional investors with what Clapp (2014) calls “financial distance” from the biopolitical implications of food speculation. Finally, manuscript three combines Gramsci’s concepts of hegemony and ‘the intellectual’ with the concept of performativity to investigate the ideological role that public intellectuals and the rhetorical actor the market play in the proliferation and governance of commodity index speculation. The first two manuscripts take an empirically mixed method approach by combining regression analysis with discourse analysis, while the third relies on interview data and discourse analysis. The findings show that financial speculation by index swap dealers and hedge funds did indeed significantly contribute to the price volatility of food commodities between June 2006 and December 2014. The results from the interview data affirm these findings. The discourse analysis of the interview data shows that public intellectuals and rhetorical characters such as ‘the market’ play powerful roles in shaping how food speculation is promoted, regulated and normalized. The significance of the findings is three-fold. First, the empirical findings show that a link does exist between financial speculation and food price volatility. Second, the findings indicate that the post-2008 CFTC and the Dodd-Frank reforms are unlikely to reduce financial speculation or the price volatility that it causes. Third, the findings suggest that institutional investors (such as pension funds) should think critically about how they use commodity index speculation as a way of generating financial earnings.

The Art of Enduring Contradictory Goals: Challenges in the Institutional Co‐construction of a ‘Good Death’

This paper focuses on the normative notion of ‘good death’, its practical relevance as a frame of reference for ‘death work’ procedures in institutional elder care in Switzerland and the ways in which it may be challenged within migrant ‘dying trajectories’. In contemporary palliative care, the concept of ‘good death’ focuses on the ideal of an autonomous dying person, cared for under a specialised biomedical authority. Transferred to the nursing home context, characterised by long-term basic care for the very old under conditions of scarce resources, the notion of ‘good death’ is broken down into ready-to-use, pragmatic elements of daily routines. At the same time, nursing homes are increasingly confronted with socially and culturally diversified populations. Based on ethnographic findings, we give insight into current practices of institutional ‘death work’ and tensions arising between contradicting notions of a ‘good death’, by referring to decision-making, life-prolonging measures, notions on food/feeding and the administration of sedative painkillers.

Past, Present, and Future: The Food Service Industry and Its Changes

In the article - Past, Present, and Future: The Food Service Industry and Its Changes - by Brother Herman E. Zaccarelli, International Director, Restaurant, Hotel and Institutional Management Institute at Purdue University, Brother Zaccarelli initially states: “Educators play an important role in the evolution of the food service industry. The author discusses that evolution and suggests how educators can be change agents along with management in that evolutionary progression.” The author goes on to wax philosophically, as well as speak generically about the food service industry; to why it offers fascinating and rewarding careers. Additionally, he writes about the influence educators have on students in this regard. “Educators can speak about how the food service industry has benefited them both personally and professionally,” says Brother Zaccarelli. “We get excited about alerting students to the many opportunities and, in fact, serve as “salespersons” for the industry to whoever (school administrators, legislators, and peers in the educational institution) will listen.” Brother Zaccarelli also speaks to growth and changes in food service, and even more importantly about the people and faces behind everything that food service, and hospitality in general comprise. The author will have you know, that people are what drive an educator. “What makes the food service industry so great? At the heart of this question's answer is people: the people whom it serves in institutional and commercial operations of all types; the people who work within it; the people who provide the goods, services, and equipment to it; the people who study it,” says Brother Zaccarelli. “All of these groups have, of course, a vested personal and/or professional interest in seeing our industry improve.” Another concept the author would like you to absorb, and it’s even more so true today than yesterday, is the prevalence of convergence and divergence within food service. For food service and beyond, it is the common denominators and differences that make the hospitality-food service industry so dynamic and vibrant. These are the winds of change presented to an educator who wants to have a positive impact on students. The author warns that the many elements involved in the food service industry conspire to erode quality of service in an industry that is also persistently expanding, and whose cornerstone principles are underpinned by service itself. “The three concerns addressed - quality, employees, and marketing - are intimately related,” Brother Zaccarelli says in stripping-down the industry to bare essentials. He defines and addresses the issues related to each with an eye toward how education can reconcile said issues.